Forums - Proper usage of "fcvCornerFast9InMasku8" function

Hi,

Thanks for your reply. I got your point but still its not working  if I do follow changes. Actually I am trying the fastcorner example itself, by using mask but its not happening. I dint understand why this is happening.

   int count = dataBufWidth*dataBufHeight; // 
   uint8_t maskArray[count/8];
   memset(maskArray, 0, (count/8)*sizeof(uint8_t));

   int rectX,rectY,rectWidth,rectHeight;
   rectX = 200;//dataBufWidth/4;
   rectY = 120;//dataBufHeight/4;
   rectWidth = 400;//dataBufWidth/2;
   rectHeight = 240;//dataBufHeight/2;

   for (int i = 0; i< rectHeight; i++) {

	   int startPoint = dataBufWidth*(rectY + i) + rectX;
	   for(int j = 0; j < rectWidth; j++ ) {
		   int index = startPoint +j;
		   maskArray[index>>3] |=(0x10000000>>(index%8));
	   }
   }



   fcvCornerFast9InMasku8  ( (uint8_t*)dataBuf,
		   	   	  dataBufWidth,
		   	   	  dataBufHeight,
		   	   	  0,
		   	           state.cornerThreshold,
				7,
				state.corners,
				MAX_CORNERS_TO_DETECT,
				&state.numCorners,
				maskArray,
			         dataBufWidth,
			         dataBufHeight
    );
Cheers,
Shravan

Hi,

I understood the concept of mask. I understood that for every pixel value we use one bit and the 1 or 0 value in the bit will consider that to include or exclude. What I am trying is I want to extract features or points from the image in certain region or in rectangle only. Thats what the for loop I have written there. But when I do that I am getting the dots(points) I mean the features or corners in the entire image. I want to get the corners only in particular region or rectangular area. The output what I am getting is the corners in the entire image. The input I am giving is,

   jimgData = env->GetByteArrayElements( img, &isCopy );

   uint8_t*  dataBuf= (uint8_t*)jimgData; 










Cheers,
Shravan