Functions
FASTCV_API void	fcvCornerFast9u8 (const uint8_t __restrict src, unsigned int srcWidth, unsigned int srcHeight, unsigned int srcStride, int barrier, unsigned int border, uint32_t __restrict xy, unsigned int nCornersMax, uint32_t *__restrict nCorners)
	Extracts FAST corners from the image. This function tests the whole image for corners (apart from the border). FAST-9 looks for continuous segments on the pixel ring of 9 pixels or more.
FASTCV_API void	fcvCornerFast9InMasku8 (const uint8_t __restrict src, unsigned int srcWidth, unsigned int srcHeight, unsigned int srcStride, int barrier, unsigned int border, uint32_t __restrict xy, unsigned int nCornersMax, uint32_t __restrict nCorners, const uint8_t __restrict mask, unsigned int maskWidth, unsigned int maskHeight)
	Extracts FAST corners from the image. This function takes a bit mask so that only image areas masked with '0' are tested for corners (if these areas are also not part of the border). FAST-9 looks for continuous segments on the pixel ring of 9 pixels or more.
FASTCV_API void	fcvCornerFast10u8 (const uint8_t __restrict src, uint32_t srcWidth, uint32_t srcHeight, uint32_t srcStride, int32_t barrier, uint32_t border, uint32_t __restrict xy, uint32_t nCornersMax, uint32_t *__restrict nCorners)
	Extracts FAST corners from the image. This function tests the whole image for corners (apart from the border). FAST-10 looks for continuous segments on the pixel ring of 10 pixels or more.
FASTCV_API void	fcvCornerFast10InMasku8 (const uint8_t __restrict src, uint32_t srcWidth, uint32_t srcHeight, uint32_t srcStride, int32_t barrier, uint32_t border, uint32_t __restrict xy, uint32_t nCornersMax, uint32_t __restrict nCorners, const uint8_t __restrict mask, uint32_t maskWidth, uint32_t maskHeight)
	Extracts FAST corners from the image. This function takes a bit mask so that only image areas masked with '0' are tested for corners (if these areas are also not part of the border). FAST-10 looks for continuous segments on the pixel ring of 10 pixels or more.
FASTCV_API void	fcvCornerHarrisu8 (const uint8_t __restrict src, unsigned int srcWidth, unsigned int srcHeight, unsigned int srcStride, unsigned int border, uint32_t __restrict xy, unsigned int nCornersMax, uint32_t *__restrict nCorners, int threshold)
	Extracts Harris corners from the image. This function tests the whole image for corners (apart from the border).
FASTCV_API unsigned int	fcvLocalHarrisMaxu8 (const uint8_t __restrict src, unsigned int srcWidth, unsigned int srcHeight, unsigned int srcStride, unsigned int posX, unsigned int posY, unsigned int maxX, unsigned int maxY, int maxScore)
	Local Harris Max applies the Harris Corner algorithm on an 11x11 patch within an image to determine if a corner is present.
FASTCV_API void	fcvCornerHarrisInMasku8 (const uint8_t __restrict src, unsigned int srcWidth, unsigned int srcHeight, unsigned int srcStride, unsigned int border, uint32_t __restrict xy, unsigned int nCornersMax, uint32_t __restrict nCorners, int threshold, const uint8_t __restrict mask, unsigned int maskWidth, unsigned int maskHeight)
	Extracts Harris corners from the image. This function takes a bit mask so that only image areas masked with '0' are tested for corners (if these areas are also not part of the border).
FASTCV_API void	fcvCornerHarrisAdaptiveu8 (const uint8_t __restrict src, uint32_t srcWidth, uint32_t srcHeight, uint32_t srcStride, uint32_t border, float32_t __restrict xy, uint32_t nCornersMax, uint32_t *__restrict nCorners, int32_t threshold)
	Extracts Harris corners from the image. This function tests the whole image for corners (apart from the border). It is an improved version which is more robust to low contrast images.
FASTCV_API fcvStatus	fcvCornerHarrisScoreu8 (const uint8_t __restrict src, uint32_t srcWidth, uint32_t srcHeight, uint32_t srcStride, float32_t __restrict harrisResp, uint32_t respStride, uint32_t __restrict xy, uint32_t nCornersMax, uint32_t __restrict nCorners, float32_t threshold, float32_t sensitivity, uint32_t kernelSize, uint32_t blockSize, uint32_t nmsEnabled, float32_t minDistance, uint32_t normalizeResponse)
	Extracts Harris corners from the image. ATTENTION: Compared to fcvCornerHarrisu8, this API gives more accurate results in exchange for slower execution time. .
FASTCV_API void	fcvCornerFast9Scoreu8 (const uint8_t __restrict src, unsigned int srcWidth, unsigned int srcHeight, unsigned int srcStride, int barrier, unsigned int border, uint32_t __restrict xy, uint32_t __restrict scores, unsigned int nCornersMax, uint32_t __restrict nCorners)
	Extracts FAST corners and scores from the image.
FASTCV_API void	fcvCornerFast9InMaskScoreu8 (const uint8_t __restrict src, unsigned int srcWidth, unsigned int srcHeight, unsigned int srcStride, int barrier, unsigned int border, uint32_t __restrict xy, uint32_t __restrict scores, unsigned int nCornersMax, uint32_t __restrict nCorners, const uint8_t *__restrict mask, unsigned int maskWidth, unsigned int maskHeight)
	Extracts FAST corners and scores from the image.
FASTCV_API void	fcvCornerFast9Scoreu8_v2 (const uint8_t __restrict src, unsigned int srcWidth, unsigned int srcHeight, unsigned int srcStride, int barrier, unsigned int border, uint32_t __restrict xy, uint32_t __restrict scores, unsigned int nCornersMax, uint32_t __restrict nCorners, uint32_t nmsEnabled, void *__restrict tempBuf)
	Extracts FAST corners and scores from the image.
FASTCV_API void	fcvCornerFast9InMaskScoreu8_v2 (const uint8_t __restrict src, unsigned int srcWidth, unsigned int srcHeight, unsigned int srcStride, int barrier, unsigned int border, uint32_t __restrict xy, uint32_t __restrict scores, unsigned int nCornersMax, uint32_t __restrict nCorners, const uint8_t __restrict mask, unsigned int maskWidth, unsigned int maskHeight, uint32_t nmsEnabled, void __restrict tempBuf)
	Extracts FAST corners and scores from the image based on the mask. The mask specifies pixels to be ignored by the detector.
FASTCV_API void	fcvCornerFast10Scoreu8 (const uint8_t __restrict src, uint32_t srcWidth, uint32_t srcHeight, uint32_t srcStride, int32_t barrier, uint32_t border, uint32_t __restrict xy, uint32_t __restrict scores, uint32_t nCornersMax, uint32_t __restrict nCorners, uint32_t nmsEnabled, void *__restrict tempBuf)
	Extracts FAST corners and scores from the image.
FASTCV_API void	fcvCornerFast10InMaskScoreu8 (const uint8_t __restrict src, uint32_t srcWidth, uint32_t srcHeight, uint32_t srcStride, int32_t barrier, uint32_t border, uint32_t __restrict xy, uint32_t __restrict scores, uint32_t nCornersMax, uint32_t __restrict nCorners, const uint8_t __restrict mask, uint32_t maskWidth, uint32_t maskHeight, uint32_t nmsEnabled, void __restrict tempBuf)
	Extracts FAST corners and scores from the image based on the mask. The mask specifies pixels to be ignored by the detector.
FASTCV_API void	fcvBoundingRectangle (const uint32_t __restrict xy, uint32_t numPoints, uint32_t rectTopLeftX, uint32_t rectTopLeftY, uint32_t rectWidth, uint32_t *rectHeight)
	Function to find the bounding rectangle of a set of points.
FASTCV_API uint32_t	fcvKMeansTreeSearch36x10s8 (const int8_t __restrict nodeChildrenCenter, const uint32_t __restrict nodeChildrenInvLenQ32, const uint32_t __restrict nodeChildrenIndex, const uint8_t __restrict nodeNumChildren, uint32_t numNodes, const int8_t *__restrict key)
	Search K-Means tree, where each node connects to up to 10 children, and the center (mean) is a 36-tuple vector of 8-bit signed value.
FASTCV_API int	fcvLinearSearchPrepare8x36s8 (uint32_t __restrict dbLUT, uint32_t numDBLUT, int8_t __restrict descDB, uint32_t __restrict descDBInvLenQ38, uint16_t __restrict descDBTargetId, uint32_t *__restrict descDBOldIdx, uint32_t numDescDB)
	Sorts in-place the pairs of <descDB, descDBInvLenQ38 > according to descDBTargetId.
FASTCV_API void	fcvLinearSearch8x36s8 (const uint32_t __restrict dbLUT, uint32_t numDBLUT, const int8_t __restrict descDB, const uint32_t __restrict descDBInvLenQ38, const uint16_t __restrict descDBTargetId, uint32_t numDescDB, const int8_t __restrict srcDesc, const uint32_t __restrict srcDescInvLenQ38, const uint32_t __restrict srcDescIdx, uint32_t numSrcDesc, const uint16_t __restrict targetsToIgnore, uint32_t numTargetsToIgnore, uint32_t maxDistanceQ31, uint32_t __restrict correspondenceDBIdx, uint32_t __restrict correspondenceSrcDescIdx, uint32_t __restrict correspondenceDistanceQ31, uint32_t maxNumCorrespondences, uint32_t __restrict numCorrespondences)
	Perform linear search of descriptor in a database.
FASTCV_API void	fcvFindContoursExternalu8 (uint8_t __restrict src, uint32_t srcWidth, uint32_t srcHeight, uint32_t srcStride, uint32_t maxNumContours, uint32_t __restrict numContours, uint32_t __restrict numContourPoints, uint32_t __restrict contourStartPoints, uint32_t __restrict pointBuffer, uint32_t pointBufferSize, int32_t hierarchy[][4], void *contourHandle)
	Finds only extreme outer contours in a binary image. There is no nesting relationship between contours. It sets hierarchy[i][2]=hierarchy[i][3]=-1 for all the contours.
FASTCV_API void	fcvFindContoursListu8 (uint8_t __restrict src, uint32_t srcWidth, uint32_t srcHeight, uint32_t srcStride, uint32_t maxNumContours, uint32_t __restrict numContours, uint32_t __restrict numContourPoints, uint32_t __restrict contourStartPoints, uint32_t __restrict pointBuffer, uint32_t pointBufferSize, void *contourHandle)
	Finds contours in a binary image without any hierarchical relationships.
FASTCV_API void	fcvFindContoursCcompu8 (uint8_t __restrict src, uint32_t srcWidth, uint32_t srcHeight, uint32_t srcStride, uint32_t maxNumContours, uint32_t __restrict numContours, uint32_t __restrict holeFlag, uint32_t __restrict numContourPoints, uint32_t *__restrict contourStartPoints, uint32_t __restrict pointBuffer, uint32_t pointBufferSize, int32_t hierarchy[][4], void *contourHandle)
	Finds contours in a binary image and organizes them into a two-level hierarchy. At the top level, there are external boundaries of the components. At the second level, there are boundaries of the holes. If there is another contour inside a hole of a connected component, it is still put at the top level.
FASTCV_API void	fcvFindContoursTreeu8 (uint8_t __restrict src, uint32_t srcWidth, uint32_t srcHeight, uint32_t srcStride, uint32_t maxNumContours, uint32_t __restrict numContours, uint32_t __restrict holeFlag, uint32_t __restrict numContourPoints, uint32_t *__restrict contourStartPoints, uint32_t __restrict pointBuffer, uint32_t pointBufferSize, int32_t hierarchy[][4], void *contourHandle)
	Finds contours in a binary image and reconstructs a full hierarchy of nested contours.
FASTCV_API void *	fcvFindContoursAllocate (uint32_t srcStride)
	Allocates assistant and intermediate data for contour.
FASTCV_API void	fcvFindContoursDelete (void *contourHandle)
	Deallocates assistant and intermediate data for contour.
FASTCV_API int	fcvKDTreeCreate36s8f32 (const int8_t __restrict vectors, const float32_t __restrict invLengths, int numVectors, fcvKDTreeDatas8f32 **kdtrees)
	create KDTrees for dataset of 36D vectors
FASTCV_API int	fcvKDTreeDestroy36s8f32 (fcvKDTreeDatas8f32 *kdtrees)
	release KDTrees data structures
FASTCV_API int	fcvKDTreeQuery36s8f32 (fcvKDTreeDatas8f32 kdtrees, const int8_t __restrict query, float32_t queryInvLen, int maxNNs, float32_t maxDist, int maxChecks, const uint8_t __restrict mask, int32_t numNNsFound, int32_t __restrict NNInds, float32_t __restrict NNDists)
	find nearest neighbors (NN) for query
FASTCV_API void	fcvHoughCircleu8 (const uint8_t __restrict src, uint32_t srcWidth, uint32_t srcHeight, uint32_t srcStride, fcvCircle __restrict circles, uint32_t __restrict numCircle, uint32_t maxCircle, uint32_t minDist, uint32_t cannyThreshold, uint32_t accThreshold, uint32_t minRadius, uint32_t maxRadius, void __restrict data)
	Finds circles in a grayscale image using Hough transform.
FASTCV_API void	fcvHoughLineu8 (const uint8_t __restrict src, uint32_t srcWidth, uint32_t srcHeight, uint32_t srcStride, float32_t threshold, uint32_t maxLines, uint32_t __restrict pNumLines, fcvLine *__restrict pLines)
	Performs Hough Line detection.
FASTCV_API void	fcvImageMomentsu8 (const uint8_t __restrict src, uint32_t srcWidth, uint32_t srcHeight, uint32_t srcStride, fcvMoments moments, uint8_t binary)
	Computes weighted average (moment) of the image pixels' intensities.
FASTCV_API void	fcvImageMomentss32 (const int32_t __restrict src, uint32_t srcWidth, uint32_t srcHeight, uint32_t srcStride, fcvMoments moments, uint8_t binary)
	Computes weighted average (moment) of the image pixels' intensities.
FASTCV_API void	fcvImageMomentsf32 (const float32_t __restrict src, uint32_t srcWidth, uint32_t srcHeight, uint32_t srcStride, fcvMoments moments, uint8_t binary)
	Computes weighted average (moment) of the image pixels' intensities.
FASTCV_API void	fcvImageDetectEdgePixelsu8 (const int16_t __restrict gxgy, const uint32_t __restrict mag, uint32_t gradStride, uint32_t topLeftX, uint32_t topLeftY, uint32_t width, uint32_t height, uint32_t gridSize, float32_t threshold, uint32_t nEdgePixelsMax, uint32_t __restrict nEdgePixels, uint32_t __restrict coordEdgePixels)
	Extracts edge locations from the image. This function tests for edges a grid of pixels within a bounding box.
FASTCV_API fcvStatus	fcvGLBPu8 (const uint8_t __restrict src, uint32_t srcWidth, uint32_t srcHeight, uint32_t srcStride, uint32_t radius, uint32_t neighbors, uint8_t __restrict dst, uint32_t dstStride)
	Computes the Generalized Local Binary Pattern Features for a single channel image.
FASTCV_API fcvStatus	fcvCornerRefineSubPixu8 (const uint8_t __restrict src, uint32_t srcWidth, uint32_t srcHeight, uint32_t srcStride, uint32_t blockWidth, uint32_t blockHeight, uint32_t maxIterations, float32_t stopCriteria, const uint32_t __restrict xyInitial, uint32_t nCorners, float32_t *__restrict xyOut)
	Refine corner location.
FASTCV_API fcvStatus	fcvGoodFeatureToTracku8 (const uint8_t __restrict src, uint32_t srcWidth, uint32_t srcHeight, uint32_t srcStride, float32_t distanceMin, uint32_t border, float32_t barrier, uint32_t __restrict xy, uint32_t maxnumcorners, uint32_t *__restrict numcorners)
	Extract strong corners from image to track.
FASTCV_API fcvStatus	fcvFindMultipleMaximau8 (const uint8_t __restrict src, uint32_t srcWidth, uint32_t srcHeight, uint32_t srcStride, const float32_t __restrict pos, const float32_t __restrict normal, uint32_t maxDistance, uint32_t maxNumMaxima, int32_t minGradient, float32_t maxAngleDiff, float32_t __restrict maxima, uint32_t *__restrict numMaxima)
	Find multiple maxima along the normal direction of the line.
FASTCV_API fcvStatus	fcvImageDetectLineSegmentsu8 (const fcvPyramidLevel_v2 __restrict srcPyr, uint32_t pyrLevel, uint32_t doBlurImage, float32_t maxLineAngle, uint32_t minLineLength, uint32_t minMagnitude, uint32_t maxLineNum, uint32_t __restrict indexBuffer, fcvLineSegment __restrict lineSegments, uint32_t __restrict numLineSegments)
	Extract the straight line segments from the image.

Detailed Description

Fast corner detection, harris corner detection, canny edge detection, etc.

Function Documentation

FASTCV_API void fcvBoundingRectangle	(	const uint32_t *__restrict	xy,
		uint32_t	numPoints,
		uint32_t *	rectTopLeftX,
		uint32_t *	rectTopLeftY,
		uint32_t *	rectWidth,
		uint32_t *	rectHeight
	)

Function to find the bounding rectangle of a set of points.

Parameters:

[in]	xy	Set of points (x,y) for which the bounding rectangle has to be found. The points are expressed in interleaved format: [x1,y1,x2,y2....]
[in]	numPoints	Number of points in the array.
[out]	rectTopLeftX	Lower left's X value for the rectangle.
[out]	rectTopLeftY	Lower Left's Y value for the rectangle;
[out]	rectWidth	Width of the rectangle.
[out]	rectHeight	Height of the rectangle.

FASTCV_API void fcvCornerFast10InMaskScoreu8	(	const uint8_t *__restrict	src,
		uint32_t	srcWidth,
		uint32_t	srcHeight,
		uint32_t	srcStride,
		int32_t	barrier,
		uint32_t	border,
		uint32_t *__restrict	xy,
		uint32_t *__restrict	scores,
		uint32_t	nCornersMax,
		uint32_t *__restrict	nCorners,
		const uint8_t *__restrict	mask,
		uint32_t	maskWidth,
		uint32_t	maskHeight,
		uint32_t	nmsEnabled,
		void *__restrict	tempBuf
	)

Extracts FAST corners and scores from the image based on the mask. The mask specifies pixels to be ignored by the detector.

Parameters:

src	8-bit grayscale image where keypoints are detected NOTE: data should be 128-bit aligned.
srcWidth	image width NOTE: should be a multiple of 8.
srcHeight	Image height
srcStride	Stride of image (i.e., how many pixels between column 0 of row 1 and column 0 of row 2). NOTE: should be a multiple of 8.
barrier	FAST threshold. The threshold is used to compare difference between intensity value of the central pixel and pixels on a circle surrounding this pixel.
border	Number for pixels to ignore from top,bottom,right,left of the image WARNING: If border < 3, it will be default to 3. WARNING: srcWidth and srcHeight must be > 2 x border
xy	Pointer to the output array cointaining the interleaved x,y position of the detected corners. NOTE: Remember to allocate double the size of
nCornersMax	NOTE: data should be 128-bit aligned.
scores	Pointer to the output array containing the scores of the detected corners. The score is the highest threshold that can still validate the detected corner. Must be greater than barrier. A higher score value indicates a stronger corner feature. For example, a corner of score 108 is stronger than a corner of score 50. NOTE: data should be 128-bit aligned.
nCornersMax	Maximum number of corners. The function exits when the maximum number of corners is exceeded. NOTE: This number should account for the number of key points before non-maximum suppression.
nCorners	pointer to an integer storing the number of corners detected
mask	Mask used to omit regions of the image. For allowed mask sizes refer to
maskWidth	and
maskHeight.	The mask is so defined to work with multiple scales if necessary. For any pixel set to '1' in the mask, the corresponding pixel in the image will be ignored. NOTE: data should be 128-bit aligned.
maskWidth	Width of the mask. Both width and height of the mask must be 'k' times image width and height, where k = 1/2, 1/4 , 1/8 , 1, 2, 4 and 8.
maskHeight	Height of the mask. Both width and height of the mask must be 'k' times image width and height, where k = 1/2, 1/4 , 1/8 , 1, 2, 4 and 8.
nmsEnabled	Enable non-maximum suppresion to prune weak key points (0=disabled, 1=enabled) NOTE: When NMS is enabled, be sure to assign large enough nCornersMax to store raw key points before NMS
tempBuf	Pointer to scratch buffer if nms is enabled, otherwise it can be NULL. Size of buffer: (3nCornersMax+srcHeight+1)4 bytes NOTE: data should be 128-bit aligned.

FASTCV_API void fcvCornerFast10InMasku8	(	const uint8_t *__restrict	src,
		uint32_t	srcWidth,
		uint32_t	srcHeight,
		uint32_t	srcStride,
		int32_t	barrier,
		uint32_t	border,
		uint32_t *__restrict	xy,
		uint32_t	nCornersMax,
		uint32_t *__restrict	nCorners,
		const uint8_t *__restrict	mask,
		uint32_t	maskWidth,
		uint32_t	maskHeight
	)

Extracts FAST corners from the image. This function takes a bit mask so that only image areas masked with '0' are tested for corners (if these areas are also not part of the border). FAST-10 looks for continuous segments on the pixel ring of 10 pixels or more.

Parameters:

src	pointer to grayscale image with one byte per pixel WARNING: should be 128-bit aligned.
srcWidth	image width WARNING: must be <= 2048. WARNING: should be a multiple of 8.
srcHeight	image height
srcStride	Stride of image (i.e., how many pixels between column 0 of row 1 and column 0 of row 2).
barrier	FAST threshold. The threshold is used to compare difference between intensity value of the central pixel and pixels on a circle surrounding this pixel.
border	Number for pixels to ignore from top,bottom,right,left of the image WARNING: If border < 3, it will be default to 3. WARNING: srcWidth and srcHeight must be > 2 x border
xy	pointer to the output array containing the interleaved x,y position of the detected corners WARNING: should be 128-bit aligned. NOTE: Remember to allocate double the size of
nCornersMax
nCornersMax	Maximum number of corners. The function exists when the maximum number of corners is exceeded
nCorners	pointer to an integer storing the number of corners detected
mask	Per-pixel mask for each pixel represented in input image. If a bit set to 0, pixel will be a candidate for corner detection. If a bit set to 1, pixel will be ignored.
maskWidth	Width of the mask. Both width and height of the mask must be 'k' times image width and height, where k = 1/2, 1/4 , 1/8 , 1, 2, 4 and 8.
maskHeight	Height of the mask. Both width and height of the mask must be 'k' times image width and height, where k = 1/2, 1/4 , 1/8 , 1, 2, 4 and 8.

FASTCV_API void fcvCornerFast10Scoreu8	(	const uint8_t *__restrict	src,
		uint32_t	srcWidth,
		uint32_t	srcHeight,
		uint32_t	srcStride,
		int32_t	barrier,
		uint32_t	border,
		uint32_t *__restrict	xy,
		uint32_t *__restrict	scores,
		uint32_t	nCornersMax,
		uint32_t *__restrict	nCorners,
		uint32_t	nmsEnabled,
		void *__restrict	tempBuf
	)

Extracts FAST corners and scores from the image.

non-maximum suppression can be enabled to reduce the number of false corners.

Parameters:

src	8-bit image where keypoints are detected. Size of buffer is srcStridesrcHeight bytes. NOTE:* should be 128-bit aligned.
srcWidth	Image width, the number of pixels in a row. NOTE: should be a multiple of 8.
srcHeight	Image height
srcStride	Stride of image is the number of bytes between column 0 of row 1 and column 0 of row 2 in data memory. If left at 0 srcStride is default to srcWidth. NOTE: should be a multiple of 8.
barrier	FAST threshold. The threshold is used to compare difference between intensity value of the central pixel and pixels on a circle surrounding this pixel.
border	Number for pixels to ignore from top,bottom,right,left of the image WARNING: If border < 3, it will be default to 3. WARNING: srcWidth and srcHeight must be > 2 x border
xy	Pointer to the output array cointaining the interleaved x,y position of the detected corners. NOTE: Remember to allocate double the size of
nCornersMax	NOTE: should be 128-bit aligned.
scores	Pointer to the output array containing the scores of the detected corners. The score is the highest threshold that can still validate the detected corner. Must be greater than barrier. A higher score value indicates a stronger corner feature. For example, a corner of score 108 is stronger than a corner of score 50. NOTE: should be 128-bit aligned. NOTE: size of buffer is
nCornersMax
nCornersMax	Maximum number of corners. The function exits when the maximum number of corners is exceeded. NOTE: This number should account for the number of key points before non-maximum suppression.
nCorners	pointer to an integer storing the number of corners detected
nmsEnabled	Enable non-maximum suppresion to prune weak key points (0=disabled, 1=enabled) NOTE: When NMS is enabled, be sure to assign large enough nCornersMax to store raw key points before NMS
tempBuf	Pointer to scratch buffer if nms is enabled, otherwise it can be NULL. Size of buffer: (3nCornersMax+srcHeight+1)4 bytes NOTE: should be 128-bit aligned.

FASTCV_API void fcvCornerFast10u8	(	const uint8_t *__restrict	src,
		uint32_t	srcWidth,
		uint32_t	srcHeight,
		uint32_t	srcStride,
		int32_t	barrier,
		uint32_t	border,
		uint32_t *__restrict	xy,
		uint32_t	nCornersMax,
		uint32_t *__restrict	nCorners
	)

Extracts FAST corners from the image. This function tests the whole image for corners (apart from the border). FAST-10 looks for continuous segments on the pixel ring of 10 pixels or more.

Parameters:

src	Pointer to grayscale image with one byte per pixel WARNING: should be 128-bit aligned.
srcWidth	Input image width WARNING: should be a multiple of 8. WARNING: must be <= 2048.
srcHeight	Image height
srcStride	Stride of image (i.e., how many pixels between column 0 of row 1 and column 0 of row 2). If 0 is passed, srcStride is set to width.
barrier	FAST threshold. The threshold is used to compare difference between intensity value of the central pixel and pixels on a circle surrounding this pixel.
border	Number for pixels to ignore from top,bottom,right,left of the image WARNING: If border < 3, it will be default to 3. WARNING: srcWidth and srcHeight must be > 2 x border
xy	pointer to the output array containing the interleaved x,y position of the detected corners e.g. struct { int x, y; } xy; WARNING: should be 128-bit aligned. NOTE: Remember to allocate double the size of
nCornersMax
nCornersMax	Maximum number of corners. The function exists when the maximum number of corners is exceeded
nCorners	pointer to an integer storing the number of corners detected

FASTCV_API void fcvCornerFast9InMaskScoreu8	(	const uint8_t *__restrict	src,
		unsigned int	srcWidth,
		unsigned int	srcHeight,
		unsigned int	srcStride,
		int	barrier,
		unsigned int	border,
		uint32_t *__restrict	xy,
		uint32_t *__restrict	scores,
		unsigned int	nCornersMax,
		uint32_t *__restrict	nCorners,
		const uint8_t *__restrict	mask,
		unsigned int	maskWidth,
		unsigned int	maskHeight
	)

Extracts FAST corners and scores from the image.

Parameters:

src	Grayscale image with one byte per pixel NOTE: should be 128-bit aligned.
srcWidth	image width NOTE: should be a multiple of 8. WARNING: must be <= 2048.
srcHeight	image height
srcStride	Stride of image (i.e., how many pixels between column 0 of row 1 and column 0 of row 2).
barrier	FAST threshold. The threshold is used to compare difference between intensity value of the central pixel and pixels on a circle surrounding this pixel.
border	Number for pixels to ignore from top,bottom,right,left of the image WARNING: If border < 3, it will be default to 3. WARNING: srcWidth and srcHeight must be > 2 x border
xy	Pointer to the output array cointaining the interleaved x,y position of the detected corners. NOTE: Remember to allocate double the size of
nCornersMax	NOTE: should be 128-bit aligned.
scores	Pointer to the output array containing the scores of the detected corners. The score is the highest threshold that can still validate the detected corner. Must be greater than barrier. A higher score value indicates a stronger corner feature. For example, a corner of score 108 is stronger than a corner of score 50. NOTE: should be 128-bit aligned.
nCornersMax	Maximum number of corners. The function exits when the maximum number of corners is exceeded.
nCorners	pointer to an integer storing the number of corners detected
mask	Per-pixel mask for each pixel represented in input image. If a bit set to 0, pixel will be a candidate for corner detection. If a bit set to 1, pixel will be ignored.
maskWidth	Width of the mask. Both width and height of the mask must be 'k' times image width and height, where k = 1/2, 1/4 , 1/8 , 1, 2, 4 and 8.
maskHeight	Height of the mask. Both width and height of the mask must be 'k' times image width and height, where k = 1/2, 1/4 , 1/8 , 1, 2, 4 and 8.

FASTCV_API void fcvCornerFast9InMaskScoreu8_v2	(	const uint8_t *__restrict	src,
		unsigned int	srcWidth,
		unsigned int	srcHeight,
		unsigned int	srcStride,
		int	barrier,
		unsigned int	border,
		uint32_t *__restrict	xy,
		uint32_t *__restrict	scores,
		unsigned int	nCornersMax,
		uint32_t *__restrict	nCorners,
		const uint8_t *__restrict	mask,
		unsigned int	maskWidth,
		unsigned int	maskHeight,
		uint32_t	nmsEnabled,
		void *__restrict	tempBuf
	)

Extracts FAST corners and scores from the image based on the mask. The mask specifies pixels to be ignored by the detector.

ATTENTION: This function is a duplication of fcvCornerFast9InMaskScoreu8() with the addition of extra parameters. This function has been added to allow for backward compatibility with the original function. When the 2.0.0 release of this library is made, this function will be renamed to: fcvCornerFast9InMaskScoreu8, fcvCornerFast9InMaskScoreu8_v2 will be removed, and the current signature for fcvCornerFast9InMaskScoreu8 will be removed. Until 2.0.0, the developer should use this implementation with the expectation of renaming it to fcvCornerFast9InMaskScoreu8 when transitioning to 2.0.0.

non-maximum suppression can be enabled to reduce the number of false corners.

Parameters:

src	8-bit grayscale image where keypoints are detected. Size of buffer is srcStridesrcHeight bytes. NOTE:* should be 128-bit aligned.
srcWidth	Image width, the number of pixels in a row. NOTE: should be a multiple of 8.
srcHeight	Image height
srcStride	Stride of image is the number of bytes between column 0 of row 1 and column 0 of row 2 in data memory. If left at 0 srcStride is default to srcWidth. NOTE: should be a multiple of 8.
barrier	FAST threshold. The threshold is used to compare difference between intensity value of the central pixel and pixels on a circle surrounding this pixel.
border	Number for pixels to ignore from top,bottom,right,left of the image WARNING: If border < 3, it will be default to 3. WARNING: srcWidth and srcHeight must be > 2 x border
xy	Pointer to the output array cointaining the interleaved x,y position of the detected corners. NOTE: Remember to allocate double the size of
nCornersMax	NOTE: should be 128-bit aligned.
scores	Pointer to the output array containing the scores of the detected corners. The score is the highest threshold that can still validate the detected corner. Must be greater than barrier. A higher score value indicates a stronger corner feature. For example, a corner of score 108 is stronger than a corner of score 50. NOTE: should be 128-bit aligned. NOTE: size of buffer is
nCornersMax
nCornersMax	Maximum number of corners. The function exits when the maximum number of corners is exceeded. NOTE: This number should account for the number of key points before non-maximum suppression.
nCorners	Pointer to an integer storing the number of corners detected
mask	Mask used to omit regions of the image. For allowed mask sizes refer to
maskWidth	and
maskHeight	. The mask is so defined to work with multiple scales if necessary. For any pixel set to '1' in the mask, the corresponding pixel in the image will be ignored. NOTE: should be 128-bit aligned.
maskWidth	Width of the mask. Both width and height of the mask must be 'k' times image width and height, where k = 1/2, 1/4 , 1/8 , 1, 2, 4 and 8.
maskHeight	Height of the mask. Both width and height of the mask must be 'k' times image width and height, where k = 1/2, 1/4 , 1/8 , 1, 2, 4 and 8.
nmsEnabled	Enable non-maximum suppresion to prune weak key points (0=disabled, 1=enabled) NOTE: When NMS is enabled, be sure to assign large enough nCornersMax to store raw key points before NMS
tempBuf	Pointer to scratch buffer if nms is enabled, otherwise it can be NULL. Size of buffer: (3nCornersMax+srcHeight+1)4 bytes NOTE: should be 128-bit aligned.

FASTCV_API void fcvCornerFast9InMasku8	(	const uint8_t *__restrict	src,
		unsigned int	srcWidth,
		unsigned int	srcHeight,
		unsigned int	srcStride,
		int	barrier,
		unsigned int	border,
		uint32_t *__restrict	xy,
		unsigned int	nCornersMax,
		uint32_t *__restrict	nCorners,
		const uint8_t *__restrict	mask,
		unsigned int	maskWidth,
		unsigned int	maskHeight
	)

Extracts FAST corners from the image. This function takes a bit mask so that only image areas masked with '0' are tested for corners (if these areas are also not part of the border). FAST-9 looks for continuous segments on the pixel ring of 9 pixels or more.

Parameters:

src	pointer to grayscale image with one byte per pixel WARNING: should be 128-bit aligned.
srcWidth	image width WARNING: must be <= 2048. WARNING: should be a multiple of 8.
srcHeight	image height
srcStride	Stride of image (i.e., how many pixels between column 0 of row 1 and column 0 of row 2). WARNING: should be a multiple of 8. If left at 0 srcStride is default to srcWidth.
barrier	FAST threshold. The threshold is used to compare difference between intensity value of the central pixel and pixels on a circle surrounding this pixel.
border	Number for pixels to ignore from top,bottom,right,left of the image WARNING: If border < 3, it will be default to 3. WARNING: srcWidth and srcHeight must be > 2 x border
xy	pointer to the output array containing the interleaved x,y position of the detected corners WARNING: should be 128-bit aligned. NOTE: Remember to allocate double the size of
nCornersMax
nCornersMax	Maximum number of corners. The function exits when the maximum number of corners is exceeded
nCorners	pointer to an integer storing the number of corners detected
mask	Per-pixel mask for each pixel represented in input image. If a bit set to 0, pixel will be a candidate for corner detection. If a bit set to 1, pixel will be ignored.
maskWidth	Width of the mask. Both width and height of the mask must be 'k' times image width and height, where k = 1/2, 1/4 , 1/8 , 1, 2, 4 and 8.
maskHeight	Height of the mask. Both width and height of the mask must be 'k' times image width and height, where k = 1/2, 1/4 , 1/8 , 1, 2, 4 and 8.

FASTCV_API void fcvCornerFast9Scoreu8	(	const uint8_t *__restrict	src,
		unsigned int	srcWidth,
		unsigned int	srcHeight,
		unsigned int	srcStride,
		int	barrier,
		unsigned int	border,
		uint32_t *__restrict	xy,
		uint32_t *__restrict	scores,
		unsigned int	nCornersMax,
		uint32_t *__restrict	nCorners
	)

Extracts FAST corners and scores from the image.

Parameters:

src	8-bit image NOTE: should be 128-bit aligned.
srcWidth	Image width NOTE: should be a multiple of 8. WARNING: must be <= 2048.
srcHeight	image height
srcStride	Stride of image (i.e., how many pixels between column 0 of row 1 and column 0 of row 2).
barrier	FAST threshold. The threshold is used to compare difference between intensity value of the central pixel and pixels on a circle surrounding this pixel.
border	Number for pixels to ignore from top,bottom,right,left of the image WARNING: If border < 3, it will be default to 3. WARNING: srcWidth and srcHeight must be > 2 x border
xy	pointer to the output array cointaining the interleaved x,y position of the detected corners. NOTE: Remember to allocate double the size of
nCornersMax	NOTE: should be 128-bit aligned.
scores	Pointer to the output array containing the scores of the detected corners. The score is the highest threshold that can still validate the detected corner. Must be greater than barrier. A higher score value indicates a stronger corner feature. For example, a corner of score 108 is stronger than a corner of score 50. NOTE: should be 128-bit aligned.
nCornersMax	Maximum number of corners. The function exits when the maximum number of corners is exceeded.
nCorners	pointer to an integer storing the number of corners detected

FASTCV_API void fcvCornerFast9Scoreu8_v2	(	const uint8_t *__restrict	src,
		unsigned int	srcWidth,
		unsigned int	srcHeight,
		unsigned int	srcStride,
		int	barrier,
		unsigned int	border,
		uint32_t *__restrict	xy,
		uint32_t *__restrict	scores,
		unsigned int	nCornersMax,
		uint32_t *__restrict	nCorners,
		uint32_t	nmsEnabled,
		void *__restrict	tempBuf
	)

Extracts FAST corners and scores from the image.

ATTENTION: This function is a duplication of fcvCornerFast9Scoreu8() with the addition of extra parameters. This function has been added to allow for backward compatibility with the original function. When the 2.0.0 release of this library is made, this function will be renamed to: fcvCornerFast9Scoreu8, fcvCornerFast9Scoreu8_v2 will be removed, and the current signature for fcvCornerFast9Scoreu8 will be removed. Until 2.0.0, the developer should use this implementation with the expectation of renaming it to fcvCornerFast9Scoreu8 when transitioning to 2.0.0.

non-maximum suppression can be enabled to reduce the number of false corners.

Parameters:

src	8-bit image where keypoints are detected. Size of buffer is srcStridesrcHeight bytes. NOTE:* should be 128-bit aligned.
srcWidth	Image width, the number of pixels in a row. NOTE: should be a multiple of 8.
srcHeight	Image height
srcStride	Stride of image is the number of bytes between column 0 of row 1 and column 0 of row 2 in data memory. If left at 0 srcStride is default to srcWidth. NOTE: should be a multiple of 8.
barrier	FAST threshold. The threshold is used to compare difference between intensity value of the central pixel and pixels on a circle surrounding this pixel.
border	Number for pixels to ignore from top,bottom,right,left of the image WARNING: If border < 3, it will be default to 3. WARNING: srcWidth and srcHeight must be > 2 x border
xy	Pointer to the output array cointaining the interleaved x,y position of the detected corners. NOTE: Remember to allocate double the size of
nCornersMax	NOTE: should be 128-bit aligned.
scores	Pointer to the output array containing the scores of the detected corners. The score is the highest threshold that can still validate the detected corner. Must be greater than barrier. A higher score value indicates a stronger corner feature. For example, a corner of score 108 is stronger than a corner of score 50. NOTE: should be 128-bit aligned. NOTE: size of buffer is
nCornersMax
nCornersMax	Maximum number of corners. The function exits when the maximum number of corners is exceeded. NOTE: This number should account for the number of key points before non-maximum suppression.
nCorners	Pointer to an integer storing the number of corners detected
nmsEnabled	Enable non-maximum suppresion to prune weak key points (0=disabled, 1=enabled) NOTE: When NMS is enabled, be sure to assign large enough nCornersMax to store raw key points before NMS
tempBuf	Pointer to scratch buffer if nms is enabled, otherwise it can be NULL. Size of buffer: (3nCornersMax+srcHeight+1)4 bytes NOTE: should be 128-bit aligned.

FASTCV_API void fcvCornerFast9u8	(	const uint8_t *__restrict	src,
		unsigned int	srcWidth,
		unsigned int	srcHeight,
		unsigned int	srcStride,
		int	barrier,
		unsigned int	border,
		uint32_t *__restrict	xy,
		unsigned int	nCornersMax,
		uint32_t *__restrict	nCorners
	)

Extracts FAST corners from the image. This function tests the whole image for corners (apart from the border). FAST-9 looks for continuous segments on the pixel ring of 9 pixels or more.

Parameters:

src	Pointer to grayscale image with one byte per pixel WARNING: should be 128-bit aligned.
srcWidth	Input image width WARNING: should be a multiple of 8. WARNING: must be <= 2048.
srcHeight	Image height
srcStride	Stride of image (i.e., how many pixels between column 0 of row 1 and column 0 of row 2). If 0 is passed, srcStride is set to width. WARNING: should be a multiple of 8.
barrier	FAST threshold. The threshold is used to compare difference between intensity value of the central pixel and pixels on a circle surrounding this pixel.
border	Number for pixels to ignore from top,bottom,right,left of the image WARNING: If border < 3, it will be default to 3. WARNING: srcWidth and srcHeight must be > 2 x border
xy	pointer to the output array containing the interleaved x,y position of the detected corners e.g. struct { int x, y; } xy; WARNING: should be 128-bit aligned. NOTE: Remember to allocate double the size of
nCornersMax
nCornersMax	Maximum number of corners. The function exits when the maximum number of corners is exceeded
nCorners	pointer to an integer storing the number of corners detected

FASTCV_API void fcvCornerHarrisAdaptiveu8	(	const uint8_t *__restrict	src,
		uint32_t	srcWidth,
		uint32_t	srcHeight,
		uint32_t	srcStride,
		uint32_t	border,
		float32_t *__restrict	xy,
		uint32_t	nCornersMax,
		uint32_t *__restrict	nCorners,
		int32_t	threshold
	)

Extracts Harris corners from the image. This function tests the whole image for corners (apart from the border). It is an improved version which is more robust to low contrast images.

Parameters:

src	Pointer to grayscale image with one byte per pixel WARNING: should be 128-bit aligned.
srcWidth	Input image width
srcHeight	Image height
srcStride	Stride of image (i.e., how many pixels between column 0 of row 1 and column 0 of row 2). WARNING: should be a multiple of 8.
border	Number for pixels to ignore from top,bottom,right,left of the image
xy	pointer to the output array containing the interleaved x,y position of the detected corners WARNING: should be 128-bit aligned. NOTE: Remember to allocate double the size of
nCornersMax
nCornersMax	Maximum number of corners. The function exits when the maximum number of corners is exceeded
nCorners	pointer to an integer storing the number of corners detected
threshold	Minimum "Harris Score" or "Harris Corner Response" of a pixel for it to be regarded as a corner.

FASTCV_API void fcvCornerHarrisInMasku8	(	const uint8_t *__restrict	src,
		unsigned int	srcWidth,
		unsigned int	srcHeight,
		unsigned int	srcStride,
		unsigned int	border,
		uint32_t *__restrict	xy,
		unsigned int	nCornersMax,
		uint32_t *__restrict	nCorners,
		int	threshold,
		const uint8_t *__restrict	mask,
		unsigned int	maskWidth,
		unsigned int	maskHeight
	)

Extracts Harris corners from the image. This function takes a bit mask so that only image areas masked with '0' are tested for corners (if these areas are also not part of the border).

Parameters:

src	pointer to grayscale image with one byte per pixel WARNING: should be 128-bit aligned.
srcWidth	image width WARNING: should be a multiple of 8.
srcHeight	image height
srcStride	Stride of image (i.e., how many pixels between column 0 of row 1 and column 0 of row 2).
border	Number for pixels to ignore from top,bottom,right,left of the image
xy	pointer to the output array containing the interleaved x,y position of the detected corners WARNING: should be 128-bit aligned.
nCornersMax	Maximum number of corners. The function exits when the maximum number of corners is exceeded
nCorners	pointer to an integer storing the number of corners detected
threshold	Minimum "Harris Score" or "Harris Corner Respose" of a pixel for it to be regarded as a corner.
mask	Per-pixel mask for each pixel represented in input image. If a bit set to 0, pixel will be a candidate for corner detection. If a bit set to 1, pixel will be ignored.
maskWidth	Width of the mask. Both width and height of the mask must be 'k' times image width and height, where k = 1/2, 1/4 , 1/8 , 1, 2, 4 and 8.
maskHeight	Height of the mask. Both width and height of the mask must be 'k' times image width and height, where k = 1/2, 1/4 , 1/8 , 1, 2, 4 and 8.

Returns:: 0 if successful.

FASTCV_API fcvStatus fcvCornerHarrisScoreu8	(	const uint8_t *__restrict	src,
		uint32_t	srcWidth,
		uint32_t	srcHeight,
		uint32_t	srcStride,
		float32_t *__restrict	harrisResp,
		uint32_t	respStride,
		uint32_t *__restrict	xy,
		uint32_t	nCornersMax,
		uint32_t *__restrict	nCorners,
		float32_t	threshold,
		float32_t	sensitivity,
		uint32_t	kernelSize,
		uint32_t	blockSize,
		uint32_t	nmsEnabled,
		float32_t	minDistance,
		uint32_t	normalizeResponse
	)

Extracts Harris corners from the image.
ATTENTION: Compared to fcvCornerHarrisu8, this API gives more accurate results in exchange for slower execution time.

.

DO NOT USE THIS API unless for testing purposes. This API can be removed without notice.

This function extracts Harris Corner features from the image. The input is an unsigned 8 bit image. Based on the values of the kernel size, the block size, the sensitivity, the function generates a Harris Response map (Harris Score). This map is then thresholded using the threshold parameter to locate local maxima. Additionally, if the Non Maximum Suppression flag is enabled, the function performs non maximum suppression of the thresholded response using the min distance parameter to calculate the neighborhood.

Parameters:

src	Input unsigned 8 bit image from which corner features are to be detected WARNING: should be 128-bit aligned.
srcWidth	Input image width
srcHeight	Input Image height
srcStride	Input image stride, i.e. the gap (in terms of bytes) between the first element of a row and that of the successive row. If srcStride is equal to 0, it will be set to srcWidth. NOTE: should be a multiple of 8
harrisResp	The computed Harris Response Map of the image. If the
normalizeResponse	flag is set, then all values in the map are normalized between 0 and 255. If the
normalizeResponse	flag is not set, then the map is not normalized to this range. This buffer MUST be allocated as srcWidthsrcHeightsizeof(float32_t).
respStride	Harris response stride, i.e. the gap (in terms of bytes) between the first element of a row and that of the successive row. If respStride is equal to 0, it will be set to srcWidth * sizeof(float32_t). NOTE: should be a multiple of 8
xy	pointer to the output array containing the interleaved x,y positions of the detected corners. WARNING: should be 128-bit aligned. NOTE: Remember to allocate double the size of
nCornersMax
nCornersMax	Maximum number of corners that should be detected. The function exits when the maximum number of corners is exceeded. NOTE: This number should account for the number of key points before non-maximum suppression.
nCorners	pointer to an integer storing the number of corners detected
threshold	Minimum "Harris Score" or "Harris Corner Response" of a pixel for it to be regarded as a corner. If the
normalizeResponse	flag is set, then this parameter MUST be a value between 0 and 255. If the
normalizeResponse	flag is not set, then this parameter can be any value in the range of int32_t. This parameter is used to threshold
harrisResp	to detect corner features.
sensitivity	This parameter represents the sensitivity threshold from the Harris Stephens equation. Typical values are between 0.04 and 0.06
kernelSize	Size of the Sobel Kernel used to compute the gradients from the input image MUST be 3,5 or 7.
blockSize	Size of an average block for computing a derivative covariation matrix over each pixel neighborhood.
nmsEnabled	A flag to enable or disable non maximum suppression. Set flag to 1 to enable it and 0 to disable. NOTE: When NMS is enabled, be sure to assign large enough nCornersMax to store raw key points before NMS
minDistance	The radial euclidean distance to perform non-maximum suppression.
normalizeResponse	This parameter is a flag to enable or disable normalization of the harris response. If it is set, then it enables normalization of the response to the range between 0 and 255. If it is not set, then the response is NOT normalized to this range.

Returns:: FASTCV_SUCCESS upon success. Other status codes upon failure.

FASTCV_API void fcvCornerHarrisu8	(	const uint8_t *__restrict	src,
		unsigned int	srcWidth,
		unsigned int	srcHeight,
		unsigned int	srcStride,
		unsigned int	border,
		uint32_t *__restrict	xy,
		unsigned int	nCornersMax,
		uint32_t *__restrict	nCorners,
		int	threshold
	)

Extracts Harris corners from the image. This function tests the whole image for corners (apart from the border).

Parameters:

src	Pointer to grayscale image with one byte per pixel WARNING: should be 128-bit aligned.
srcWidth	Input image width WARNING: should be a multiple of 8.
srcHeight	Image height
srcStride	Stride of image (i.e., how many pixels between column 0 of row 1 and column 0 of row 2).
border	Number for pixels to ignore from top,bottom,right,left of the image
xy	pointer to the output array containing the interleaved x,y position of the detected corners WARNING: should be 128-bit aligned. NOTE: Remember to allocate double the size of
nCornersMax
nCornersMax	Maximum number of corners. The function exits when the maximum number of corners is exceeded
nCorners	pointer to an integer storing the number of corners detected
threshold	Minimum "Harris Score" or "Harris Corner Response" of a pixel for it to be regarded as a corner.

Returns:: 0 if successful.

FASTCV_API fcvStatus fcvCornerRefineSubPixu8	(	const uint8_t *__restrict	src,
		uint32_t	srcWidth,
		uint32_t	srcHeight,
		uint32_t	srcStride,
		uint32_t	blockWidth,
		uint32_t	blockHeight,
		uint32_t	maxIterations,
		float32_t	stopCriteria,
		const uint32_t *__restrict	xyInitial,
		uint32_t	nCorners,
		float32_t *__restrict	xyOut
	)

Refine corner location.

Refine the detected corners location into sub-Pixels which is more precise than integer pixels

Parameters:

src	Input uint8_t image. Size of buffer is srcStridesrcHeight bytes. WARNING:* should be 128-bit aligned.
srcWidth	Input image width.
srcHeight	Input image height.
srcStride	Input image stride, i.e. the gap (in terms of bytes) between the first element of a row and that of the successive row
blockWidth	Width of the location search window.
blockHeight	Height of the location search window.
maxIterations	Maximum number of iteration to refine
stopCriteria	Improvement threshold, iteration stop if the corner position moves less by this value
xyInitial	Pointer to the initial input array containing the interleaved x,y position of the corner
nCorners	Number of the corners
xyOut	Pointer to the output array containing the refined interleaved x,y position of the corner

FASTCV_API void* fcvFindContoursAllocate ( uint32_t srcStride )

Allocates assistant and intermediate data for contour.

Parameters:

srcStride Stride of image (i.e., how many pixels between column 0 of row 1 and column 0 of row 2).

Returns:: Pointer to allocated data

FASTCV_API void fcvFindContoursCcompu8	(	uint8_t *__restrict	src,
		uint32_t	srcWidth,
		uint32_t	srcHeight,
		uint32_t	srcStride,
		uint32_t	maxNumContours,
		uint32_t *__restrict	numContours,
		uint32_t *__restrict	holeFlag,
		uint32_t *__restrict	numContourPoints,
		uint32_t **__restrict	contourStartPoints,
		uint32_t *__restrict	pointBuffer,
		uint32_t	pointBufferSize,
		int32_t	hierarchy[][4],
		void *	contourHandle
	)

Finds contours in a binary image and organizes them into a two-level hierarchy. At the top level, there are external boundaries of the components. At the second level, there are boundaries of the holes. If there is another contour inside a hole of a connected component, it is still put at the top level.

Parameters:

src	Grayscale image with one byte per pixel. Non-zero pixels are treated as 1's. Zero pixels remain 0's, so the image is treated as binary.
srcWidth	Image width
srcHeight	Image height
srcStride	Stride of image (i.e., how many pixels between column 0 of row 1 and column 0 of row 2).
maxNumContours	Maximum number of contours can be found (<= 126)
numContours	Number of actually found contours
holeFlag	Hole flag for each found contour to indicate whether it is a hole or not
numContourPoints	Number of points in each found contour
contourStartPoints	Pointers to the start point of each found contour
pointBuffer	Pointer to point buffer for contour points' coordinates. It should be allocated before calling this function.
pointBufferSize	Size of point buffer in terms of uint32_t
hierarchy	Information about the image topology. It has numContours elements. For each contour i, the elements hierarchy[i][0], hiearchy[i][1], hiearchy[i][2], and hiearchy[i][3] are set to 0-based indices of the next and previous contours at the same hierarchical level, the first child contour and the parent contour, respectively. If for a contour i there are no next, previous, parent, or nested contours, the corresponding elements of hierarchy[i] will be negative.
contourHandle	Pointer to assistant and intermediate data. It should be allocated by fcvFindContoursAllocate() and deallocated by fcvFindContoursDelete().

FASTCV_API void fcvFindContoursDelete ( void * contourHandle )

Deallocates assistant and intermediate data for contour.

Parameters:

contourHandle Pointer to assistant and intermediate data

FASTCV_API void fcvFindContoursExternalu8	(	uint8_t *__restrict	src,
		uint32_t	srcWidth,
		uint32_t	srcHeight,
		uint32_t	srcStride,
		uint32_t	maxNumContours,
		uint32_t *__restrict	numContours,
		uint32_t *__restrict	numContourPoints,
		uint32_t **__restrict	contourStartPoints,
		uint32_t *__restrict	pointBuffer,
		uint32_t	pointBufferSize,
		int32_t	hierarchy[][4],
		void *	contourHandle
	)

Finds only extreme outer contours in a binary image. There is no nesting relationship between contours. It sets hierarchy[i][2]=hierarchy[i][3]=-1 for all the contours.

Parameters:

src	Grayscale image with one byte per pixel. Non-zero pixels are treated as 1's. Zero pixels remain 0's, so the image is treated as binary.
srcWidth	Image width
srcHeight	Image height
srcStride	Stride of image (i.e., how many pixels between column 0 of row 1 and column 0 of row 2).
maxNumContours	Maximum number of contours can be found
numContours	Number of actually found contours
numContourPoints	Number of points in each found contour
contourStartPoints	Pointers to the start point of each found contour
pointBuffer	Pointer to point buffer for contour points' coordinates. It should be allocated before calling this function.
pointBufferSize	Size of point buffer in terms of uint32_t
hierarchy	Information about the image topology. It has numContours elements. For each contour i, the elements hierarchy[i][0], hiearchy[i][1], hiearchy[i][2], and hiearchy[i][3] are set to 0-based indices of the next and previous contours at the same hierarchical level, the first child contour and the parent contour, respectively. If for a contour i there are no next, previous, parent, or nested contours, the corresponding elements of hierarchy[i] will be negative.
contourHandle	Pointer to assistant and intermediate data. It should be allocated by fcvFindContoursAllocate() and deallocated by fcvFindContoursDelete().

FASTCV_API void fcvFindContoursListu8	(	uint8_t *__restrict	src,
		uint32_t	srcWidth,
		uint32_t	srcHeight,
		uint32_t	srcStride,
		uint32_t	maxNumContours,
		uint32_t *__restrict	numContours,
		uint32_t *__restrict	numContourPoints,
		uint32_t **__restrict	contourStartPoints,
		uint32_t *__restrict	pointBuffer,
		uint32_t	pointBufferSize,
		void *	contourHandle
	)

Finds contours in a binary image without any hierarchical relationships.

Parameters:

src	Grayscale image with one byte per pixel. Non-zero pixels are treated as 1's. Zero pixels remain 0's, so the image is treated as binary.
srcWidth	Image width
srcHeight	Image height
srcStride	Stride of image (i.e., how many pixels between column 0 of row 1 and column 0 of row 2).
maxNumContours	Maximum number of contours can be found
numContours	Number of actually found contours
numContourPoints	Number of points in each found contour
contourStartPoints	Pointers to the start point of each found contour
pointBuffer	Pointer to point buffer for contour points' coordinates. It should be allocated before calling this function.
pointBufferSize	Size of point buffer in terms of uint32_t
contourHandle	Pointer to assistant and intermediate data. It should be allocated by fcvFindContoursAllocate() and deallocated by fcvFindContoursDelete().

FASTCV_API void fcvFindContoursTreeu8	(	uint8_t *__restrict	src,
		uint32_t	srcWidth,
		uint32_t	srcHeight,
		uint32_t	srcStride,
		uint32_t	maxNumContours,
		uint32_t *__restrict	numContours,
		uint32_t *__restrict	holeFlag,
		uint32_t *__restrict	numContourPoints,
		uint32_t **__restrict	contourStartPoints,
		uint32_t *__restrict	pointBuffer,
		uint32_t	pointBufferSize,
		int32_t	hierarchy[][4],
		void *	contourHandle
	)

Finds contours in a binary image and reconstructs a full hierarchy of nested contours.

Parameters:

src	Grayscale image with one byte per pixel. Non-zero pixels are treated as 1's. Zero pixels remain 0's, so the image is treated as binary.
srcWidth	Image width
srcHeight	Image height
srcStride	Stride of image (i.e., how many pixels between column 0 of row 1 and column 0 of row 2).
numContours	Number of actually found contours
maxNumContours	Maximum number of contours can be found (<= 126)
holeFlag	Hole flag for each found contour to indicate whether it is a hole or not
numContourPoints	Number of points in each found contour
contourStartPoints	Pointers to the start point of each found contour
pointBuffer	Pointer to point buffer for contour points' coordinates. It should be allocated before calling this function.
pointBufferSize	Size of point buffer in terms of uint32_t
hierarchy	Information about the image topology. It has numContours elements. For each contour i, the elements hierarchy[i][0], hiearchy[i][1], hiearchy[i][2], and hiearchy[i][3] are set to 0-based indices of the next and previous contours at the same hierarchical level, the first child contour and the parent contour, respectively. If for a contour i there are no next, previous, parent, or nested contours, the corresponding elements of hierarchy[i] will be negative.
contourHandle	Pointer to assistant and intermediate data. It should be allocated by fcvFindContoursAllocate() and deallocated by fcvFindContoursDelete().

FASTCV_API fcvStatus fcvFindMultipleMaximau8	(	const uint8_t *__restrict	src,
		uint32_t	srcWidth,
		uint32_t	srcHeight,
		uint32_t	srcStride,
		const float32_t *__restrict	pos,
		const float32_t *__restrict	normal,
		uint32_t	maxDistance,
		uint32_t	maxNumMaxima,
		int32_t	minGradient,
		float32_t	maxAngleDiff,
		float32_t *__restrict	maxima,
		uint32_t *__restrict	numMaxima
	)

Find multiple maxima along the normal direction of the line.

Parameters:

src	8-bit input image
srcWidth	Input image width
srcHeight	Input image height
srcStride	Input image stride
pos	2D position to start searching maximas in the input image
normal	Normalized line normal at pos
maxDistance	Search distance along the normal direction; [-normalmaxDistance, normalmaxDistance]
maxNumMaxima	Maximum maxima to find, e.g., 5
minGradient	Minimum 1D gradient of the pixels on the search line (normal direction)
maxAngleDiff	Cosine value threshold to filter the pixels that have large angle difference
maxima	List of found maxima 1D positions; Actuall 2D position of maxima = (normal * 1D position) + pos
numMaxima	Number of found maxima

Returns:: FASTCV_SUCCESS upon success. Other status codes upon failure.

FASTCV_API fcvStatus fcvGLBPu8	(	const uint8_t *__restrict	src,
		uint32_t	srcWidth,
		uint32_t	srcHeight,
		uint32_t	srcStride,
		uint32_t	radius,
		uint32_t	neighbors,
		uint8_t *__restrict	dst,
		uint32_t	dstStride
	)

Computes the Generalized Local Binary Pattern Features for a single channel image.

The function computes the Circular Local Binary Pattern (LBP) Code of each pixel of an input image "src" A number of neighboring pixels "neighbors" are sampled from a circle of radius "radius" around each pixel to compute the LBP code. In this implementation, it is assumed that the number of neighbors vary between 1 & 8. It is also assumed that the dimensions of the output image "dst" is computed as follows from the size of the input image �src": dstWidth = srcWidth - 2*radius, and dstHeight = srcHeight - 2*radius.

Parameters:

src	Input unsigned 8-bit integer image. Size of buffer is srcStridesrcHeight bytes. WARNING:* should be 128-bit aligned.
srcWidth	Width of the source image.
srcHeight	Height of the source image.
srcStride	Stride of the Image in bytes. NOTE: if 0, srcStride is set as srcWidth. WARNING: should be multiple of 8, and at least as much as srcWidth if not 0.
radius	The radius of the circle centered around each pixel. The value of radius specifies the size of the region around each pixel from which the neighbors are sampled.
neighbors	The number of neighbors sampled from the circle around each pixel. NOTE : MUST be > 0 and less than or equal to 8.
dst	Output unsigned 8-bit integer image. Size of buffer is dstStridesrcHeight bytes. The dimensions of the image are dstWidth = srcWidth - 2radius, and dstHeight = srcHeight - 2*radius.
dstStride	Stride of the output image in bytes. NOTE: dstWidth = srcWidth - 2radius, dstHeight = srcHeight - 2radius. WARNING: should be multiple of 8, and at least as much as dstWidth if not 0.

FASTCV_API fcvStatus fcvGoodFeatureToTracku8	(	const uint8_t *__restrict	src,
		uint32_t	srcWidth,
		uint32_t	srcHeight,
		uint32_t	srcStride,
		float32_t	distanceMin,
		uint32_t	border,
		float32_t	barrier,
		uint32_t *__restrict	xy,
		uint32_t	maxnumcorners,
		uint32_t *__restrict	numcorners
	)

Extract strong corners from image to track.

Extract strong corners from image to track based on the according paper "Good Feature to Track" by J.Shi and C.Tomasi

Parameters:

src	Input uint8_t image. Size of buffer is srcStridesrcHeight bytes. WARNING:* should be 128-bit aligned.
srcWidth	Input image width.
srcHeight	Input image height.
srcStride	Input image stride, i.e. the gap (in terms of bytes) between the first element of a row and that of the successive row
distanceMin	Minimum Euclidean distance between the found corners
border	Number for pixels to ignore from top,bottom
barrier	Quality threshold
xy	Pointer to the output array containing the interleaved x,y position of the detected features

Maximum number of features to detect

Pointer to integer of actual detected features number

FASTCV_API void fcvHoughCircleu8	(	const uint8_t *__restrict	src,
		uint32_t	srcWidth,
		uint32_t	srcHeight,
		uint32_t	srcStride,
		fcvCircle *__restrict	circles,
		uint32_t *__restrict	numCircle,
		uint32_t	maxCircle,
		uint32_t	minDist,
		uint32_t	cannyThreshold,
		uint32_t	accThreshold,
		uint32_t	minRadius,
		uint32_t	maxRadius,
		void *__restrict	data
	)

Finds circles in a grayscale image using Hough transform.

This function detect circles in a grayscale image. The number is up to maxCircle. The radius of circle varies from 0 to max(srcWidth, srcHeight).

Parameters:

src	8-bit, single-channel, binary source image. Size of buffer is srcStridesrcHeight bytes. WARNING:* should be 128-bit aligned. must be a 1-channel image.
srcWidth	Width of input image, the number of pixels in a row.
srcHeight	Height of input image.
srcStride	Stride of input image(in bytes) is the number of bytes between column 0 of row 1 and column 0 of row 2 in data memory. If left at 0 srcStride is default to srcWidth. NOTE: should be a multiple of 8.
circles	Pointer to fcvCircle. fcvCircle is a struct including x, y position and radius
numCircle	Pointer to numCircle. numCircle is an algorithm result indicating the number of circle detected by this algorithm.
maxCircle	Maximum number of circles.
minDist	Minimum distance between the centers of the detected circles
cannyThreshold	The higher threshold of the two passed to the Canny() edge detector (the lower one is twice smaller). default is 100.
accThreshold	The accumulator threshold for the circle centers at the detection stage. The smaller it is, the more false circles may be detected. Circles, corresponding to the larger accumulator values, will be returned first. default is 100.
minRadius	Minimum circle radius. default is 0.
maxRadius	Maximum circle radius. default is 0.
data	Pointer to a buffer required by this algorithm. The recommended size is 16 times of input image (16srcStridesrcHeigth in bytes). WARNING: should be 128-bit aligned.

Returns:: void

FASTCV_API void fcvHoughLineu8	(	const uint8_t *__restrict	src,
		uint32_t	srcWidth,
		uint32_t	srcHeight,
		uint32_t	srcStride,
		float32_t	threshold,
		uint32_t	maxLines,
		uint32_t *__restrict	pNumLines,
		fcvLine *__restrict	pLines
	)

Performs Hough Line detection.

This function detects lines in a grayscale image. The maximum number of lines detected is defined by the maxLines parameter.

Parameters:

src	8bit, single-channel, binary source image. Size of buffer is srcStride * srcHeight bytes.
srcWidth	Width of the input image, the number of pixels in a row. should be a multiple of 8.
srcHeight	Input image height in pixels.
srcStride	Stride of input image in bytes is the number of bytes between column 0 of row 1 and column 0 of row 2 in data memory. If left at 0 srcStride will default to srcWidth. NOTE: should be a multiple of 8.
threshold	Controls the minimal length of a detected line. Value must be between 0.0 and 1.0 Values close to 1.0 reduces the number of detected lines. Values close to 0.0 detect more lines, but may be noisy. Recommended value is 0.25.
maxLines	Maximum number of lines to be detected.
pNumLines	Number of lines detected. The memory for this array must be allocated by the user of the function.
pLines	Resulting lines detected. The memory for this array must be allocated by the user of the function.

Returns:: void

FASTCV_API void fcvImageDetectEdgePixelsu8	(	const int16_t *__restrict	gxgy,
		const uint32_t *__restrict	mag,
		uint32_t	gradStride,
		uint32_t	topLeftX,
		uint32_t	topLeftY,
		uint32_t	width,
		uint32_t	height,
		uint32_t	gridSize,
		float32_t	threshold,
		uint32_t	nEdgePixelsMax,
		uint32_t *__restrict	nEdgePixels,
		uint32_t *__restrict	coordEdgePixels
	)

Extracts edge locations from the image. This function tests for edges a grid of pixels within a bounding box.

Parameters:

gxgy	Pointer to gradient direction image array containing the interleaved x,y components of the direction vector.
mag	Pointer to gradient magnitude image array stored as a 4-byte unsigned integer per pixel.
gradStride	gradStride is the number of pixels between column 0 of row 1 and column 0 of row 2 in data memory for gxgy and mag. should be multiple of 8
topLeftX	The x coordinate of the top-left corner of the bounding box.
topLeftY	The y coordinate of the top-left corner of the bounding box.
width	The width of the bounding box.
height	The height of the bounding box.
gridSize	The spacing between pixels that are tested for edges.
threshold	The threshold is used for early filtering edge candidate pixels based on gradient magnitude.
nEdgePixelsMax	Maximum number of edge pixels. The function exits when the maximum number of edges is exceeded.
nEdgePixels	Pointer to an integer storing the number of edge pixels detected.
coordEdgePixels	Pointer to the output array containing the interleaved x,y position of the detected edges.

FASTCV_API fcvStatus fcvImageDetectLineSegmentsu8	(	const fcvPyramidLevel_v2 *__restrict	srcPyr,
		uint32_t	pyrLevel,
		uint32_t	doBlurImage,
		float32_t	maxLineAngle,
		uint32_t	minLineLength,
		uint32_t	minMagnitude,
		uint32_t	maxLineNum,
		uint32_t *__restrict	indexBuffer,
		fcvLineSegment *__restrict	lineSegments,
		uint32_t *__restrict	numLineSegments
	)

Extract the straight line segments from the image.

Parameters:

srcPyr	Pointer to an array of fcvPyramidLevel_v2. Only 2 levels at max will be used to extract the straight line segments.
pyrLevel	Image pyramid level, if it is set to 1, then do not use multi-scale approach. pyrLevel should be greater than or equal to 1.
doBlurImage	Do image-blurring inside the function (if the image is not blurred)
maxLineAngle	Cosine threshold to stop following (extending) pixels, e.g., cos(22.5 deg) maxLineAngle should be between [0.5 - 1.0]
minLineLength	Minimum line segment length in pixels
minMagnitude	Minimum pixel gradient magnitude, e.g., 10
maxLineNum	Maximum line segments from the image
indexBuffer	Optionally store the index(:= y * image_width + x) of the pixels consisting of the line segments into pointsList in fcvLineSegment structure. e.g., One can provide the buffer[maxLineNum*(image width + height)] Pass NULL if it is not necessary.
lineSegments	List of the detected line segments
numLineSegments	Number of found line segments

Returns:: FASTCV_SUCCESS upon success. Other status codes upon failure.

FASTCV_API void fcvImageMomentsf32	(	const float32_t *__restrict	src,
		uint32_t	srcWidth,
		uint32_t	srcHeight,
		uint32_t	srcStride,
		fcvMoments *	moments,
		uint8_t	binary
	)

Computes weighted average (moment) of the image pixels' intensities.

This function computes image moment, i.e., a certain particular weighted average (moment) of the image pixels' intensities, or a function of such moments, usually chosen to have some attractive property or interpretation. Image moments are useful to describe objects after segmentation.

Parameters:

src	Pointer to the original Input of data type float32_t. Size of buffer is srcStridesrcHeight bytes. NOTE:* should be 128-bit aligned.
srcWidth	The width of the input source image.
srcHeight	The height of the input source image.
srcStride	Stride of image is the number of bytes between column 0 of row 1 and column 0 of row 2 in data memory. If left at 0 srcStride is default to srcWidth4. NOTE:* should be a multiple of 8.
moments	Pointer to the a struct of image moments which is a certain particular weighted average (moment) of the image pixels' intensities, it includes 18 elements.
binary	if 1, binary image (0x00-black, oxff-white); if 0, grayscale image

FASTCV_API void fcvImageMomentss32	(	const int32_t *__restrict	src,
		uint32_t	srcWidth,
		uint32_t	srcHeight,
		uint32_t	srcStride,
		fcvMoments *	moments,
		uint8_t	binary
	)

Computes weighted average (moment) of the image pixels' intensities.

This function computes image moment, i.e., a certain particular weighted average (moment) of the image pixels' intensities, or a function of such moments, usually chosen to have some attractive property or interpretation. Image moments are useful to describe objects after segmentation.

Parameters:

src	Pointer to the original input of data type int32_t. Size of buffer is srcStridesrcHeight bytes. NOTE:* should be 128-bit aligned.
srcWidth	The width of the input source image.
srcHeight	The height of the input source image.
srcStride	Stride of image is the number of bytes between column 0 of row 1 and column 0 of row 2 in data memory. If left at 0 srcStride is default to srcWidth4. NOTE:* should be a multiple of 8.
moments	Pointer to the a struct of image moments which is a certain particular weighted average (moment) of the image pixels' intensities, it includes 18 elements.
binary	if 1, binary image (0x00-black, oxff-white); if 0, grayscale image

FASTCV_API void fcvImageMomentsu8	(	const uint8_t *__restrict	src,
		uint32_t	srcWidth,
		uint32_t	srcHeight,
		uint32_t	srcStride,
		fcvMoments *	moments,
		uint8_t	binary
	)

Computes weighted average (moment) of the image pixels' intensities.

This function computes image moment, i.e., a certain particular weighted average (moment) of the image pixels' intensities, or a function of such moments, usually chosen to have some attractive property or interpretation. Image moments are useful to describe objects after segmentation.

Parameters:

src	Pointer to the original Input 8-bit image. Size of buffer is srcStridesrcHeight bytes. NOTE:* should be 128-bit aligned.
srcWidth	The width of the input source image.
srcHeight	The height of the input source image.
srcStride	Stride of image is the number of bytes between column 0 of row 1 and column 0 of row 2 in data memory. If left at 0 srcStride is default to srcWidth. NOTE: should be a multiple of 8.
moments	Pointer to the a struct of image moments which is a certain particular weighted average (moment) of the image pixels' intensities, it includes 18 elements.
binary	if 1, binary image (0x00-black, oxff-white); if 0, grayscale image

FASTCV_API int fcvKDTreeCreate36s8f32	(	const int8_t *__restrict	vectors,
		const float32_t *__restrict	invLengths,
		int	numVectors,
		fcvKDTreeDatas8f32 **	kdtrees
	)

create KDTrees for dataset of 36D vectors

KDTree is very efficient search structure for multidimensional data. Usage: assume we have 36D of type int8_t data e.g. target image feature descriptors in array named vectors

int8_t* descriptors;

the number of descriptors is numVectors

int numDescriptors;

the inverse length of each descriptor in array invLengths

float32_t* invLenghts;

pointer to KDTree structure

fcvKDTreeDatas8f32* kdTree = 0;

kdTree is created as

int err = fcvKDTreeCreate36s8f32( descriptors, invLengths, numDescriptors, kdTree );

Parameters:

vectors	pointer to dataset being array of 36D vectors
invLengths	array of inverse lengths for each vector in the dataset
numVectors	number of 36D vectors in the dataset
kdtrees	address for pointer to the newly created KDTrees

Returns:: 0 - success EINVAL - invalid parameter ENOMEM - not enough memory -1 - other error

FASTCV_API int fcvKDTreeDestroy36s8f32 ( fcvKDTreeDatas8f32 * kdtrees )

release KDTrees data structures

Once we are done with all searches we should release kdTree resources

Parameters:

kdtrees KDTrees to be destroyed

Returns:: 0 - success EINVAL - invalid parameter -1 - other error

FASTCV_API int fcvKDTreeQuery36s8f32	(	fcvKDTreeDatas8f32 *	kdtrees,
		const int8_t *__restrict	query,
		float32_t	queryInvLen,
		int	maxNNs,
		float32_t	maxDist,
		int	maxChecks,
		const uint8_t *__restrict	mask,
		int32_t *	numNNsFound,
		int32_t *__restrict	NNInds,
		float32_t *__restrict	NNDists
	)

find nearest neighbors (NN) for query

Assuming KD tree creation is successful we may start using our kdTree for nearest neighbors (NN) for descriptors of camera features. Let our camera descriptors be in array camDescriptors and their number in numCamDescriptors

int8_t* camDescriptors; int numCamDescriptors;

The inverse lengths of descriptors is in

float* camDescriptorsInvLengths;

Assume we want to find 8 NNs for each camera descriptor. We declare variables for results of NN searches

#define NUM_NN 8 // number of NN required #define MAX_CHECKS 32 // max number of checks in kdtree

int32_t numFound = 0; // for numer of NNs found int32_t foundInds[ NUM_NN ]; // for indices to target descriptors float32_t foundDists[ NUM_NN ]; // for distances to target descriptors float32_t maxDist = 0.1f; // max distance to query allowed

the search for NNs for i-th query would be like this

err = fcvKDTreeQuery36s8f32( kdTree, camDescriptors + i * 36, camDescriptorsInvLengths[ i ], maxDist, MAX_CHECKS, 0, &numFound, foundInds, foundDists );

where maxDists is an upper bound on distance of NN from the query and MAX_CHECKS is max number of comparisons of query to target descriptors. The higher MAX_CHECKS the better NNs we get at the cost of longer search. Assuming everything went fine will return us search results. numFound will contain the number of target descriptors found whose distance to query is less than maxDist. foundInds will contain indices to target descriptors being NNs and foundDists their distances to query.

Parameters:

kdtrees	KDTrees
query	query vector
queryInvLen	inverse length of query vector
maxNNs	max number of NNs to be found
maxDist	max distance between NN and query
maxChecks	max number of leafs to check
mask	array of flags for all vectors in the dataset; may be NULL; if not NULL then its legth must be equal to number of dataset vectors and i-th mask corresponds to i-th vector; values: 0x00 - corresponding vector must not be considered NN regardless of its distance to query 0xFF - corresponding vector may be candidate for NN other - not supported
numNNsFound	for number of NNs found
NNInds	array for indices of found NNs; must have maxNNs length
NNDists	array for NN distances to query; must have maxNNs length

Returns:: 0 - success EINVAL - invalid parameter -1 - other error

FASTCV_API uint32_t fcvKMeansTreeSearch36x10s8	(	const int8_t *__restrict	nodeChildrenCenter,
		const uint32_t *__restrict	nodeChildrenInvLenQ32,
		const uint32_t *__restrict	nodeChildrenIndex,
		const uint8_t *__restrict	nodeNumChildren,
		uint32_t	numNodes,
		const int8_t *__restrict	key
	)

Search K-Means tree, where each node connects to up to 10 children, and the center (mean) is a 36-tuple vector of 8-bit signed value.

Parameters:

nodeChildrenCenter	A pointer to uint8_t [numNodes][10][36], which stores the center vectors of node children. The outer-most dimension represents the nodes in the tree. The middle dimension represents the children of each node. The inner-most dimension represents the tuples of the center vector. WARNING: must be 64-bit aligned.
nodeChildrenInvLenQ32	A pointer to uint32_t [numNodes][10], which stores the inverse lengths of the center vectors. The inverse lengths are in Q32 format. The outer-most dimension represents the nodes in the tree. The inner-most dimension represents the children of each node. WARNING: must be 64-bit aligned.
nodeChildrenIndex	A pointer to uint32_t [numNodes][10], which stores the indices of the children nodes. If the MSB is 0, the index points to a node within the tree. If the MSB is 1, the index (with MSB removed) points to a leaf node, which is returned by this function as the search result. See nodeChildrenInvLenQ32 for the definition of each dimension. WARNING: must be 64-bit aligned.
nodeNumChildren	A pointer to uint8_t [numNodes], which stores the number of children in each node.
numNodes	Number of nodes in the K-Means tree.
key	A pointer to int8_t [36], which stores the key to be searched.

Returns:: Index of the leaf node.

FASTCV_API void fcvLinearSearch8x36s8	(	const uint32_t *__restrict	dbLUT,
		uint32_t	numDBLUT,
		const int8_t *__restrict	descDB,
		const uint32_t *__restrict	descDBInvLenQ38,
		const uint16_t *__restrict	descDBTargetId,
		uint32_t	numDescDB,
		const int8_t *__restrict	srcDesc,
		const uint32_t *__restrict	srcDescInvLenQ38,
		const uint32_t *__restrict	srcDescIdx,
		uint32_t	numSrcDesc,
		const uint16_t *__restrict	targetsToIgnore,
		uint32_t	numTargetsToIgnore,
		uint32_t	maxDistanceQ31,
		uint32_t *__restrict	correspondenceDBIdx,
		uint32_t *__restrict	correspondenceSrcDescIdx,
		uint32_t *__restrict	correspondenceDistanceQ31,
		uint32_t	maxNumCorrespondences,
		uint32_t *__restrict	numCorrespondences
	)

Perform linear search of descriptor in a database.

Parameters:

dbLUT	A pointer to uint32_t [numDBLUT][2], which stores the starting index of descDB and the number of descriptors WARNING: must be 64-bit aligned.
numDBLUT	The size of dbLUT
descDB	A pointer to int8_t [numDescDB][36], which stores descriptors WARNING: must be 64-bit aligned.
descDBInvLenQ38	A pointer to uint32_t [numDescDB], which stores the inverse length of descDB. The value is in Q38 format.
descDBTargetId	A pointer to uint16_t [numDescDB], which stores the target id.
numDescDB	Number of descriptor in the database.
srcDesc	A pointer to int8_t [numSrcDesc][36], which stores descriptors. WARNING: must be 64-bit aligned.
srcDescInvLenQ38	A pointer to uint32_t [numSrcDec], which stores the inverse length of srcDesc. The value is in Q38 format.
srcDescIdx	A pointer to the dbLUT data
numSrcDesc	Number of source descriptor
targetsToIgnore	A list of target IDs to be ignored
numTargetsToIgnore	Number of targets to be ignored
maxDistanceQ31	Maximum distance for correspondences. In Q31 format.
correspondenceDBIdx	A pointer to uint32_t [maxNumCorrespondences], which will be used by this function to output indices of featuresDB as a part of correspondences.
correspondenceSrcDescIdx	A pointer to uint32_t [maxNumCorrespondences], which will be used by this function to output indices of descriptors as a part of correspondences.
correspondenceDistanceQ31	A pointer to uint32_t [maxNumCorrespondences], which will be used by this function to output the distances as a part of correspondences. In Q31 format.
maxNumCorrespondences	Maximum number of correspondences allowed
numCorrespondences	Number of correspondences returned by this function

FASTCV_API int fcvLinearSearchPrepare8x36s8	(	uint32_t *__restrict	dbLUT,
		uint32_t	numDBLUT,
		int8_t *__restrict	descDB,
		uint32_t *__restrict	descDBInvLenQ38,
		uint16_t *__restrict	descDBTargetId,
		uint32_t *__restrict	descDBOldIdx,
		uint32_t	numDescDB
	)

Sorts in-place the pairs of <descDB, descDBInvLenQ38 > according to descDBTargetId.

Parameters:

dbLUT	A pointer to uint32_t [numDBLUT][2], which stores the starting index of descDB and the number of descriptors WARNING: must be 64-bit aligned.
numDBLUT	The size of dbLUT
descDB	A pointer to int8_t [numDescDB][36], which stores descriptors WARNING: must be 64-bit aligned.
descDBInvLenQ38	A pointer to uint32_t [numDescDB], which stores the inverse length of descDB. The value is in Q38 format.
descDBTargetId	A pointer to uint16_t [numDescDB], which stores the target id.
descDBOldIdx	A pointer to uint32_t [numDescDB], which stores the old index of the desc before sorting
numDescDB	Number of descriptor in the database.

FASTCV_API unsigned int fcvLocalHarrisMaxu8	(	const uint8_t *__restrict	src,
		unsigned int	srcWidth,
		unsigned int	srcHeight,
		unsigned int	srcStride,
		unsigned int	posX,
		unsigned int	posY,
		unsigned int *	maxX,
		unsigned int *	maxY,
		int *	maxScore
	)

Local Harris Max applies the Harris Corner algorithm on an 11x11 patch within an image to determine if a corner is present.

Parameters:

src	Pointer to grayscale image with one byte per pixel WARNING: should be 128-bit aligned.
srcWidth	Input image width WARNING: should be a multiple of 8.
srcHeight	Image height
srcStride	Stride of image (i.e., how many pixels between column 0 of row 1 and column 0 of row 2). If srcStride == 0, then will use srcWidth.
posX	Center X coordinate of the search window
posY	Center Y coordinate of the search window
maxX	pointer to the X coordinate identified as a corner
maxY	pointer to the Y coordinate identified as a corner
maxScore	pointer to the Harris score associated with the corner

Returns:: 0 if no corner is found (maxX, maxY, and maxScore are invalid) or if posX and/or posY position the patch outside of the range of the source image. 1 if a corner is found (maxX, maxY, and maxScore are valid)

Functions

Detailed Description

Function Documentation