remove orientation kernel from keypoint program

openCL/keypoints_cpu.cl

@@ -14,163 +14,6 @@ typedef float4 keypoint;
 
 
 
-/**
- * \brief Assign an orientation to the keypoints.  This is done by creating a Gaussian weighted histogram
- *   of the gradient directions in the region.  The histogram is smoothed and the largest peak selected.
- *    The results are in the range of -PI to PI.
- *
- * Warning:
- * 			-At this stage, a keypoint is: (peak,r,c,sigma)
- 			 After this function, it will be (c,r,sigma,angle)
- *
- * @param keypoints: Pointer to global memory with current keypoints vector.
- * @param grad: Pointer to global memory with gradient norm previously calculated
- * @param ori: Pointer to global memory with gradient orientation previously calculated
- * @param counter: Pointer to global memory with actual number of keypoints previously found
- * @param hist: Pointer to shared memory with histogram (36 values per thread)
- * @param octsize: initially 1 then twiced at each octave
- * @param OriSigma : a SIFT parameter, default is 1.5. Warning : it is not "InitSigma".
- * @param nb_keypoints : maximum number of keypoints
- * @param grad_width: integer number of columns of the gradient
- * @param grad_height: integer num of lines of the gradient
- */
-
-
-__kernel void orientation_assignment(
-	__global keypoint* keypoints,
-	__global float* grad,
-	__global float* ori,
-	__global int* counter,
-	int octsize,
-	float OriSigma, //WARNING: (1.5), it is not "InitSigma (=1.6)"
-	int nb_keypoints,
-	int keypoints_start,
-	int keypoints_end,
-	int grad_width,
-	int grad_height)
-{
-	int gid0 = get_global_id(0);
-	keypoint k = keypoints[gid0];
-	if (!(keypoints_start <= gid0 && gid0 < keypoints_end && k.s1 >=0.0f ))
-		return;
-	int	bin, prev=0, next=0;
-	int i,j,r,c;
-	int old;
-	float distsq, gval, angle, interp=0.0;
-	float hist_prev,hist_curr,hist_next;
-	float hist[36];
-	//memset
-	for (i=0; i<36; i++) hist[i] = 0.0f;
-
-	int	row = (int) (k.s1 + 0.5),
-		col = (int) (k.s2 + 0.5);
-
-	float sigma = OriSigma * k.s3;
-	int	radius = (int) (sigma * 3.0);
-	int rmin = MAX(0,row - radius);
-	int cmin = MAX(0,col - radius);
-	int rmax = MIN(row + radius,grad_height - 2);
-	int cmax = MIN(col + radius,grad_width - 2);
-
-	for (r = rmin; r <= rmax; r++) {
-		for (c = cmin; c <= cmax; c++) {
-			gval = grad[r*grad_width+c];
-
-			float dif = (r - k.s1);	distsq = dif*dif;
-			dif = (c - k.s2);	distsq += dif*dif;
-
-			//distsq = (r-k.s1)*(r-k.s1) + (c-k.s2)*(c-k.s2);
-
-			if (gval > 0.0f  &&  distsq < ((float) (radius*radius)) + 0.5f) {
-				angle = ori[r*grad_width+c];
-				bin = (int) (36.0f * (angle + M_PI_F + 0.001f) / (2.0f * M_PI_F)); //why this offset ?
-				if (bin >= 0 && bin <= 36) {
-					bin = MIN(bin, 35);
-					hist[bin] += exp(- distsq / (2.0f*sigma*sigma)) * gval;
-				}
-			}
-		}
-	}
-
-
-
-	/*
-		Apply smoothing 6 times for accurate Gaussian approximation
-	*/
-
-	for (j = 0; j < 6; j++) {
-		float prev, temp; //it is CRUCIAL to re-define "prev" here, for the line below... otherwise, it won't work
-		prev = hist[35];
-		for (i = 0; i < 36; i++) {
-			temp = hist[i];
-			hist[i] = ( prev + hist[i] + hist[(i + 1 == 36) ? 0 : i + 1] ) / 3.0;
-			prev = temp;
-		}
-	}
-
-
-	/* Find maximum value in histogram */
-
-	float maxval = 0.0f;
-	int argmax = 0;
-	for (i=0; i<36; i++) {
-		if (maxval < hist[i]) {
-			maxval = hist[i];
-			argmax = i;
-		}
-	}
-
-/*
-	This maximum value in the histogram is defined as the orientation of our current keypoint
-*/	
-	prev = (argmax == 0 ? 35 : argmax - 1);
-	next = (argmax == 35 ? 0 : argmax + 1);
-	hist_prev = hist[prev];
-	hist_next = hist[next];
-	if (maxval < 0.0f) {
-		hist_prev = -hist_prev;
-		maxval = -maxval;
-		hist_next = -hist_next;
-	}
-	interp = 0.5f * (hist_prev - hist_next) / (hist_prev - 2.0f * maxval + hist_next);
-	angle = 2.0f * M_PI_F * (argmax + 0.5f + interp) / 36.0f - M_PI_F;
-
-
-	k.s0 = k.s2 *octsize; //c
-	k.s1 = k.s1 *octsize; //r
-	k.s2 = k.s3 *octsize; //sigma
-	k.s3 = angle; 		  //angle
-	keypoints[gid0] = k;
-
-	/*
-		An orientation is now assigned to our current keypoint.
-		We can create new keypoints of same (x,y,sigma) but a different angle.
-		For every local peak in histogram, every peak of value >= 80% of maxval generates a new keypoint
-	*/
-
-	for (i=0; i < 36; i++) {
-		int prev = (i == 0 ? 35 : i - 1);
-		int next = (i == 35 ? 0 : i + 1);
-		float hist_prev = hist[prev];
-		float hist_curr = hist[i];
-		float hist_next = hist[next];
-		if (hist_curr > hist_prev  &&  hist_curr > hist_next && hist_curr >= 0.8f * maxval && i != argmax) {
-			if (hist_curr < 0.0f) {
-				hist_prev = -hist_prev;
-				hist_curr = -hist_curr;
-				hist_next = -hist_next;
-			}
-			float interp = 0.5f * (hist_prev - hist_next) / (hist_prev - 2.0f * hist_curr + hist_next);
-			float angle = 2.0f * M_PI_F * (i + 0.5f + interp) /36.0 - M_PI_F;
-			if (angle >= -M_PI_F && angle <= M_PI_F) {
-				k.s3 = angle;
-				old  = atomic_inc(counter);
-				if (old < nb_keypoints) keypoints[old] = k;
-			}
-		} //end "val >= 80%*maxval"
-	}
-}
-
 /*
 **
  * \brief Compute a SIFT descriptor for each keypoint.