void camVolbergFwd(CamImage *source, CamImage *dest, CamVolbergFwdParams *params)
{
int x,y;
CamImage intermediate;
CAM_PIXEL *scanlinesrc,*scanlinedst,*intptr,*dstptr;
double *mapping;
camAllocateImage(&intermediate,dest->width,source->height,source->depth);
// First resampling : horizontal
mapping=(double*)malloc((source->width+1)*sizeof(double));
for (y=0;y<intermediate.height;y++) {
for (x=0;x<=source->width;x++) {
params->hfwd(x,y,&mapping[x]);
}
// Call Volberg's algorithm
camVolbergFwdScanline((CAM_PIXEL*)(source->imageData+y*source->widthStep), source->width,
(CAM_PIXEL*)(intermediate.imageData+y*intermediate.widthStep), intermediate.width,
mapping);
}
free(mapping);
// Second resampling : vertical
mapping=(double*)malloc((intermediate.height+1)*sizeof(double));
scanlinesrc=(CAM_PIXEL*)malloc(intermediate.height*sizeof(CAM_PIXEL));
scanlinedst=(CAM_PIXEL*)malloc(dest->height*sizeof(CAM_PIXEL));
for (x=0;x<dest->width;x++) {
intptr=((CAM_PIXEL*)intermediate.imageData)+x;
for (y=0;y<intermediate.height;y++) {
params->vfwd(x,y,&mapping[y]);
scanlinesrc[y]=*intptr;
intptr=((CAM_PIXEL*)(((char*)intptr)+intermediate.widthStep));
}
params->vfwd(x,y,&mapping[y]);
// Call Volberg's algorithm
camVolbergFwdScanline(scanlinesrc, intermediate.height,
scanlinedst, dest->height,
mapping);
dstptr=((CAM_PIXEL*)dest->imageData)+x;
for (y=0;y<dest->height;y++) {
*dstptr=scanlinedst[y];
dstptr=((CAM_PIXEL*)(((char*)dstptr)+dest->widthStep));
}
}
free(scanlinesrc);
free(scanlinedst);
free(mapping);
camDeallocateImage(&intermediate);
}
int camIntegralImage(CamImage *src, CamImage *dest)
{
int x, y;
int width, height;
CAM_PIXEL *srcptr, *srctmpptr;
unsigned long *dstptr, *dsttmpptr;
CamInternalROIPolicyStruct iROI;
unsigned long val;
#ifdef CAM_VECTORIZE
int i;
union i4vector v1, v2;
#endif
CAM_CHECK_ARGS2(camIntegralImage, src->imageData != NULL, "source image is not allocated");
if (dest->imageData==NULL) {
// Automatic allocation
camAllocateImage(dest, src->width, src->height, CAM_DEPTH_32U);
}
CAM_CHECK(camIntegralImage, camInternalROIPolicy(src, dest, &iROI, 0));
CAM_CHECK_ARGS(camIntegralImage, iROI.nChannels == 1);
CAM_CHECK_ARGS(camIntegralImage, (src->depth & CAM_DEPTH_MASK) >= 8);
CAM_CHECK_ARGS(camIntegralImage, (src->depth & CAM_DEPTH_MASK) <= (sizeof(CAM_PIXEL) * 8));
CAM_CHECK_ARGS(camIntegralImage, (dest->depth & CAM_DEPTH_MASK) == 32);
CAM_CHECK_ARGS(camIntegralImage, !(src->depth & CAM_DEPTH_SIGN));
/*
// One pass algorithm
width = iROI.srcroi.width;
height = iROI.srcroi.height;
srcptr = (CAM_PIXEL*)iROI.srcptr;
dstptr = (unsigned long*)iROI.dstptr;
srctmpptr = srcptr;
dsttmpptr = dstptr;
val = 0;
for (x = 0; x < width; x++, srcptr += iROI.srcinc, dstptr++) {
val += *srcptr;
*dstptr = val;
}
srcptr = (CAM_PIXEL*)(((char*)srctmpptr) + src->widthStep);
dstptr = (unsigned long*)(((char*)dsttmpptr) + dest->widthStep);
for (y = 1; y < height; y++) {
srctmpptr = srcptr;
dsttmpptr = dstptr;
val = 0;
for (x = 0; x < width; x++, srcptr += iROI.srcinc, dstptr++) {
val += *srcptr;
*dstptr = val + *(unsigned long*)(((char*)dstptr) - dest->widthStep);
}
srcptr = (CAM_PIXEL*)(((char*)srctmpptr) + src->widthStep);
dstptr = (unsigned long*)(((char*)dsttmpptr) + dest->widthStep);
}
*/
// Two passes algorithm
// First pass
width = iROI.srcroi.width;
height = iROI.srcroi.height;
srcptr = (CAM_PIXEL*)iROI.srcptr;
dstptr = (unsigned long*)iROI.dstptr;
for (y = 0; y < height; y++) {
srctmpptr = srcptr;
dsttmpptr = dstptr;
val = 0;
for (x = 0; x < width; x++, srcptr += iROI.srcinc, dstptr++) {
val += *srcptr;
*dstptr = val;
}
srcptr = (CAM_PIXEL*)(((char*)srctmpptr) + src->widthStep);
dstptr = (unsigned long*)(((char*)dsttmpptr) + dest->widthStep);
}
#ifndef CAM_VECTORIZE
// Second pass
dstptr = (unsigned long*)iROI.dstptr;
dstptr = (unsigned long*)(((char*)dstptr) + dest->widthStep);
for (y = 1; y < height; y++) {
dsttmpptr = dstptr;
for (x = 0; x < width; x++, dstptr++) {
*dstptr += *(unsigned long*)(((char*)dstptr) - dest->widthStep);
}
dstptr = (unsigned long*)(((char*)dsttmpptr) + dest->widthStep);
}
#else
// Second pass / SSE2 vectorized
dstptr = (unsigned long*)iROI.dstptr;
dstptr = (unsigned long*)(((char*)dstptr) + dest->widthStep);
for (y = 1; y < height; y++) {
dsttmpptr = dstptr;
for (x = 0; x < width; x+=4) {
// Add 4 pixels at once
for (i = 0; i != 4; i++, dstptr++) {
v1.i[i] = *dstptr;
v2.i[i] = *(unsigned long*)(((char*)dstptr) - dest->widthStep);
}
v1.v = v1.v + v2.v;
dstptr -= (iROI.dstinc<<2);
for (i = 0; i != 4; i++, dstptr++) *dstptr = v1.i[i];
}
for (; x < width; x++, dstptr += iROI.dstinc) {
*dstptr += *(unsigned long*)(((char*)dstptr) - dest->widthStep);
}
dstptr = (unsigned long*)(((char*)dsttmpptr) + dest->widthStep);
}
#endif
camInternalROIPolicyExit(&iROI);
return 1;
}
void test_camRecursiveKeypoints()
{
CamImage image, dest;
CamKeypoints points;
int i;
const int x = 8;
int angle;
double costheta;
double sintheta;
const int xp[4] = {-1, 1, 1, -1};
const int yp[4] = {-1, -1, 1, 1};
CamWarpingParams params;
printf("Recursive keypoints detection :\n");
camAllocateImage(&image, 256, 256, CAM_DEPTH_8U);
camAllocateKeypoints(&points, 100);
camSet(&image, 0);
// camDrawRectangle(&image, 102, 120, 156, 152, 128);
// camFillColor(&image, 103, 121, 128, -1);
camDrawRectangle(&image, 120, 50, 150, 70, 28);
camDrawRectangle(&image, 100, 35, 180, 90, 180);
// camFillColor(&image, 123, 36, 128, -1);
//
// camDrawCircle(&image, 50, 50, 10, 128);
// camFillColor(&image, 50, 50, 128, -1);
// camDrawCircle(&image, 80, 50, 5, 128);
// camFillColor(&image, 80, 50, 128, -1);
// camDrawCircle(&image, 100, 50, 3, 128);
// camFillColor(&image, 100, 50, 128, -1);
#if 1
angle = 20;
costheta = cos(angle * 2 * M_PI / 360);
sintheta = sin(angle * 2 * M_PI / 360);
for (i = 0; i < 4; i++) {
params.p[i].x = (int)floor((costheta * xp[i] - sintheta * yp[i]) * 15 + 0.5);
params.p[i].y = (int)floor((sintheta * xp[i] + costheta * yp[i]) * 15 + 0.5);
params.p[i].x += 192;
params.p[i].y += 192;
}
for (i = 0; i < 4; i++) {
camDrawLine(&image, params.p[i].x, params.p[i].y, params.p[(i+1)%4].x, params.p[(i+1)%4].y, 128);
}
camFillColor(&image, 192, 192, 128, -1);
angle = 30;
costheta = cos(angle * 2 * M_PI / 360);
sintheta = sin(angle * 2 * M_PI / 360);
for (i = 0; i < 4; i++) {
params.p[i].x = (int)floor((costheta * xp[i] - sintheta * yp[i]) * 10 + 0.5);
params.p[i].y = (int)floor((sintheta * xp[i] + costheta * yp[i]) * 10 + 0.5);
params.p[i].x += 50;
params.p[i].y += 192;
}
for (i = 0; i < 4; i++) {
camDrawLine(&image, params.p[i].x, params.p[i].y, params.p[(i+1)%4].x, params.p[(i+1)%4].y, 128);
}
camFillColor(&image, 50, 192, 128, -1);
#endif
dest.imageData = NULL;
camKeypointsRecursiveDetector(&image, NULL, &points, 20, 0);
for (i = 0; i < points.nbPoints; i++) {
printf("x=%d y=%d value=%d scale=%d size=%d angle=%d\n", points.keypoint[i]->x, points.keypoint[i]->y, points.keypoint[i]->value, points.keypoint[i]->scale, points.keypoint[i]->size, points.keypoint[i]->angle);
}
camDrawKeypoints(&points, &image, 192);
camSavePGM(&image, "output/keypoints_recursive.pgm");
camDeallocateImage(&image);
camDeallocateImage(&dest);
camFreeKeypoints(&points);
}
int
camKeypointsRecursiveDetector(CamImage *source, CamImage *integral, CamKeypoints *points, int nb_max_keypoints, int options)
{
CamImage filter;
CamInternalROIPolicyStruct iROI;
CamROI *roi, roix;
int i, width, height;
CamKeypointShort *keypoints;
int pnb_keypoints;
int nb_keypoints = 0;
unsigned int *abs_value_lines[2];
int *value_lines[2];
unsigned char *scale_lines[2];
unsigned char *lmax_lines[2];
unsigned int *lmax[2], nblmax[2];
int widthStep;
camPatchSizeParam = 16; //32 * 2 / 3; // Equivalent optimal value wrt SURF (the descriptor can partially lie outside screen)
// Parameters checking
CAM_CHECK(camKeypointsRecursiveDetector, camInternalROIPolicy(source, NULL, &iROI, 1));
CAM_CHECK_ARGS(camKeypointsRecursiveDetector, (source->depth & CAM_DEPTH_MASK) >= 8);
CAM_CHECK_ARGS(camKeypointsRecursiveDetector, points->allocated >= 0);
CAM_CHECK_ARGS(camKeypointsRecursiveDetector, source->nChannels == 1 || ((source->nChannels == 3) && (source->dataOrder == CAM_DATA_ORDER_PLANE)));
width = iROI.srcroi.width;
height = iROI.srcroi.height;
if (!integral)
{
// Compute integral image
integral = (CamImage*)malloc(sizeof(CamImage));
integral->imageData = NULL;
roi = source->roi;
camSetMaxROI(&roix, source);
roix.coi = 1;
source->roi = &roix;
camIntegralImage(source, integral); // Computed on the whole frame, not only on ROI
integral->roi = &iROI.srcroi;
source->roi = roi;
}
widthStep = integral->widthStep / 4;
// Allocate temp memory for keypoints
keypoints = (CamKeypointShort*)malloc(CAM_MAX_KEYPOINTS * sizeof(CamKeypointShort));
points->nbPoints = 0;
// Allocate value and scale lines
for (i = 0; i < 2; i++) {
scale_lines[i] = (unsigned char*)malloc(width * sizeof(unsigned char));
value_lines[i] = (int*)malloc(width * sizeof(int));
abs_value_lines[i] = (unsigned int*)malloc(width * sizeof(unsigned int));
lmax_lines[i] = (unsigned char*)malloc(width * sizeof(unsigned char));
lmax[i] = (unsigned int*)malloc(width * sizeof(unsigned int));
nblmax[i] = 0;
}
// Go !
{
int y;
int max_scale_y;
unsigned int *abs_current_value_line, *abs_previous_value_line;
int *current_value_line, *previous_value_line;
unsigned char *current_scale_line, *previous_scale_line;
unsigned char *current_lmax_line, *previous_lmax_line;
unsigned int *current_lmax, *previous_lmax;
unsigned int current_nblmax, previous_nblmax;
current_value_line = value_lines[0];
previous_value_line = value_lines[1];
abs_current_value_line = abs_value_lines[0];
abs_previous_value_line = abs_value_lines[1];
current_scale_line = scale_lines[0];
previous_scale_line = scale_lines[1];
current_lmax_line = lmax_lines[0];
previous_lmax_line = lmax_lines[1];
current_lmax = lmax[0];
previous_lmax = lmax[1];
// Fill the previous value line with a dummy value
for (i = 0; i < width; i++) {
abs_previous_value_line[i] = 0;
previous_value_line[i] = 0;
previous_scale_line[i] = 1;
previous_lmax_line[i] = 0;
}
current_nblmax = 0;
previous_nblmax = 0;
for (y = 0; y < height; y++) {
int x, v;
// max_scale is the biggest scale we may apply. It must be more than 0, otherwise we can't do any image processing
max_scale_y = (y + iROI.srcroi.yOffset) >> 1;
// The preceding formula comes from :
// - When iROI.yOffset is 0, max_scale should be 1 when y is 2 (1 pixel margin due to integral image)
// - When iROI.yOffset is 0, max_scale should be 1 when y is 3 (1 pixel margin due to integral image)
// - When iROI.yOffset is 0, max_scale should be 2 when y is 4 (1 pixel margin due to integral image)
// Check max_scale with the bottom line
v = (source->height - 1 - (y + iROI.srcroi.yOffset)) >> 1;
// The preceding formula comes from "When iROI.yOffset is 0, max_scale should be 1 when y is equal to source->height - 3
if (v < max_scale_y) max_scale_y = v;
if (max_scale_y < 1) {
// We can't compute anything for that line
for (i = 0; i < width; i++) {
current_value_line[i] = 0;
current_scale_line[i] = 1;
}
} else {
int scale_up = 1;
int current_value = 0;
unsigned int abs_current_value = 0;
int current_scale = 1;
unsigned int *ptr = ((unsigned int*)(integral->imageData + (y + iROI.srcroi.yOffset) * integral->widthStep)) + iROI.srcroi.xOffset;
int s1, s2;
for (x = 0; x < width; x++, ptr++) {
int first_scale = current_scale;
int max_scale = max_scale_y;
// Check max_scale with the left side of the frame
v = (x + iROI.srcroi.xOffset) >> 1;
if (v < max_scale) max_scale = v;
// Check max_scale with the right side of the frame
v = (source->width -1 - (x + iROI.srcroi.xOffset)) >> 1;
if (v < max_scale) max_scale = v;
// We need a scale margin in order to compute the descriptor
max_scale -= CAM_SCALE_MARGIN;
// Choose the first scale to evaluate, depending on upper and left results
if (abs_previous_value_line[x] > abs_current_value)
first_scale = previous_scale_line[x];
if (first_scale <= max_scale) {
// Evaluate at first scale
int scale = first_scale; // alias
int yoffset = scale * widthStep;
int value;
#define CAM_RECURSIVE_PATTERN \
{ \
unsigned int *ptrAi = ptr - (yoffset + scale); \
unsigned int *ptrDi = ptr + (yoffset + scale); \
unsigned int *ptrBi = ptr - (yoffset - scale); \
unsigned int *ptrCi = ptr + (yoffset - scale); \
unsigned int valin = *ptrDi - *ptrBi - *ptrCi + *ptrAi; \
unsigned int *ptrAo = ptr - ((yoffset + scale) << 1); \
unsigned int *ptrDo = ptr + ((yoffset + scale) << 1); \
unsigned int *ptrBo = ptr - ((yoffset - scale) << 1); \
unsigned int *ptrCo = ptr + ((yoffset - scale) << 1); \
unsigned int valout = *ptrDo - *ptrBo - *ptrCo + *ptrAo; \
value = valout - (valin << 2); \
}
CAM_RECURSIVE_PATTERN;
current_scale = scale;
current_value = value;
abs_current_value = abs(value);
// Let's see if we go upscale or not...
if (scale_up && scale < max_scale) {
// OK. Let's test the upscale
scale++;
yoffset += widthStep;
CAM_RECURSIVE_PATTERN;
s1 = current_scale * current_scale; s2 = scale * scale;
if (((CAM_INT64)abs(value)) * s1 > (CAM_INT64)abs_current_value * s2) {
// Yes. That was a good hint
current_scale = scale;
current_value = value;
abs_current_value = abs(value);
// Let's test again at higher scale
if (scale < max_scale) {
scale++;
yoffset += widthStep;
CAM_RECURSIVE_PATTERN;
s1 = current_scale * current_scale; s2 = scale * scale;
if (((CAM_INT64)abs(value)) * s1 > (CAM_INT64)abs_current_value * s2) {
// Even better
current_scale = scale;
current_value = value;
abs_current_value = abs(value);
// And we stop there, satisfied...
}
}
} else {
// Oh, oh... Apparently, that was not a good hint to go upscale...
// Let's try to downscale then...
scale -= 2;
if (scale > 0 && scale <= max_scale) {
yoffset -= widthStep << 1;
CAM_RECURSIVE_PATTERN;
s1 = current_scale * current_scale; s2 = scale * scale;
if (((CAM_INT64)abs(value)) * s1 > (CAM_INT64)abs_current_value * s2) {
// Yes. It's better
scale_up = 0; // This is the hint for next time
current_scale = scale;
current_value = value;
abs_current_value = abs(value);
}
// And we stop there, satisfied...
}
}
} else {
// OK. Let's test the downscale
scale--;
if (scale > 0 && scale <= max_scale) {
yoffset -= widthStep;
CAM_RECURSIVE_PATTERN;
if (((CAM_INT64)abs(value)) * current_scale * current_scale > (CAM_INT64)abs_current_value * scale * scale) {
// Yes. That was a good hint.
current_scale = scale;
current_value = value;
abs_current_value = abs(value);
// Let's test again at lower scale
scale--;
if (scale > 0 && scale <= max_scale) {
yoffset -= widthStep;
CAM_RECURSIVE_PATTERN;
s1 = current_scale * current_scale; s2 = scale * scale;
if (((CAM_INT64)abs(value)) * s1 > (CAM_INT64)abs_current_value * s2) {
// Even better
current_scale = scale;
current_value = value;
abs_current_value = abs(value);
// And we stop there, satisfied...
}
}
} else {
// Oh, oh... Apparently, that was not a good hint to go downscale...
// Let's try to upscale then...
scale += 2;
if (scale > 0 && scale <= max_scale) {
yoffset += widthStep << 1;
CAM_RECURSIVE_PATTERN;
s1 = current_scale * current_scale; s2 = scale * scale;
if (((CAM_INT64)abs(value)) * s1 > (CAM_INT64)abs_current_value * s2) {
// Yes. It's better
scale_up = 1; // This is the hint for next time
current_scale = scale;
current_value = value;
abs_current_value = abs(value);
}
// And we stop there, satisfied...
}
}
} else {
// Oh, oh... Apparently, that was not a good hint to go downscale...
// Let's try to upscale then...
scale += 2;
if (scale > 0 && scale <= max_scale) {
yoffset += widthStep;
CAM_RECURSIVE_PATTERN;
s1 = current_scale * current_scale; s2 = scale * scale;
if (((CAM_INT64)abs(value)) * s1 > (CAM_INT64)abs_current_value * s2) {
// Yes. It's better
scale_up = 1; // This is the hint for next time
current_scale = scale;
current_value = value;
abs_current_value = abs(value);
}
// And we stop there, satisfied...
}
}
}
} else {
// Skip this pixel and go back to small scale
current_value = 0;
abs_current_value = 0;
current_scale = 1;
scale_up = 1;
}
current_value = (current_value << 4) / (current_scale * current_scale);
abs_current_value = abs(current_value);
// Now, we do have the current_value, current_scale and abs_current_value
// Let's check whether it is a local maximum or not
{
// If the current value is strictly greater than all the other values, then this is a local maximum and
// the other pixels are marked as NOT being local maxima
// If the current value is greater or equal to all neighbours, then this ia marked to be a local maximum
// but the other pixels are kept as local maxima
// If the current value is greater than any neighbour, this neighbour is marked as not being a local maximum
int local_maximum = 1;
if (x > 0) {
// Compare to the left and upper-left pixel
if (abs_current_value_line[x - 1] > abs_current_value)
local_maximum = 0;
else current_lmax_line[x - 1] = 0;
if (abs_previous_value_line[x - 1] > abs_current_value)
local_maximum = 0;
else previous_lmax_line[x - 1] = 0;
}
// Compare to pixel above
if (abs_previous_value_line[x] > abs_current_value)
local_maximum = 0;
else previous_lmax_line[x] = 0;
if (x < width - 1) {
// Compare to the upper right pixel
if (abs_previous_value_line[x + 1] > abs_current_value)
local_maximum = 0;
else previous_lmax_line[x + 1] = 0;
}
if (local_maximum && abs_current_value > 0) {
current_lmax[current_nblmax++] = x;
current_lmax_line[x] = 1;
}
}
// Record the data for next line evaluation
current_value_line[x] = current_value;
abs_current_value_line[x] = abs_current_value;
current_scale_line[x] = current_scale;
//if (y == 100) {
//printf("y=%d x=%d value=%d abs=%d scale=%d\n", y, x, current_value, abs_current_value, current_scale);
//}
}
}
// Check the local maxima on the previous line, and record the keypoints IF they are local maxima
for (i = 0; i != previous_nblmax; i++) {
if (previous_lmax_line[previous_lmax[i]]) {
int scale = previous_scale_line[previous_lmax[i]];
if (scale >= CAM_MIN_SCALE) {
// Yes, we have definitely a local maximum
// Record the keypoint
keypoints[nb_keypoints].x = previous_lmax[i];
keypoints[nb_keypoints].y = y - 1;
keypoints[nb_keypoints].scale = scale;
keypoints[nb_keypoints].value = previous_value_line[previous_lmax[i]];
nb_keypoints++;
}
}
}
// Switch previous and current lines
{
unsigned char *tmp;
tmp = current_scale_line;
current_scale_line = previous_scale_line;
previous_scale_line = tmp;
}{
unsigned int *tmp;
tmp = abs_current_value_line;
abs_current_value_line = abs_previous_value_line;
abs_previous_value_line = tmp;
}{
int *tmp;
tmp = current_value_line;
current_value_line = previous_value_line;
previous_value_line = tmp;
}{
unsigned char *tmp;
tmp = current_lmax_line;
current_lmax_line = previous_lmax_line;
previous_lmax_line = tmp;
}{
unsigned int *tmp;
tmp = current_lmax;
current_lmax = previous_lmax;
previous_lmax = tmp;
}
previous_nblmax = current_nblmax;
current_nblmax = 0;
}
}
for (i = 0; i < 2; i++) {
free(value_lines[i]);
free(abs_value_lines[i]);
free(scale_lines[i]);
free(lmax_lines[i]);
free(lmax[i]);
}
// Post-processing : remove keypoints in a given neighborhood (proportionnal to scale)
for (i = 1; i < nb_keypoints; i++) {
CamKeypointShort *keypoint = &keypoints[i];
int j = i - 1;
int neighborhood = keypoint->scale >> 2;
while (j >= 0 && keypoints[j].y >= keypoint->y - neighborhood) {
CamKeypointShort *keypoint2 = &keypoints[j];
if (keypoint2->x >= keypoint->x - neighborhood && keypoint2->x <= keypoint->x + neighborhood) {
// They are next to each other...
if (abs(keypoint2->value) > abs(keypoint->value))
keypoint->scale = 0; // Let's get rid of this one... It has a lower value
else
keypoint2->scale = 0;
}
j--;
}
}
for (i = 0; i < nb_keypoints; i++)
if (!keypoints[i].scale) keypoints[i].value = 0;
if (options & CAM_UPRIGHT) {
// Remove keypoints the descriptor of which would be outside the frame boundaries
for (i = 0; i < nb_keypoints; i++) {
if (keypoints[i].scale) {
int scale = keypoints[i].scale; // Save the scale
keypoints[i].scale = (scale << 2) + 1;
if (!camKeypointDescriptorCheckBounds(&keypoints[i], integral))
keypoints[i].value = 0;
keypoints[i].scale = scale;
}
}
}
// Sort the features according to value
qsort(keypoints, nb_keypoints, sizeof(CamKeypointShort), camSortKeypointsShort);
for (i = 0; i < nb_keypoints; i++)
if (keypoints[i].value == 0) break;
nb_keypoints = i;
if (nb_keypoints > nb_max_keypoints) nb_keypoints = nb_max_keypoints;
/* Interpolation :
* Maxima : solve([y1=a*(x1-p)^2+b,y2=a*(-p)^2+b,y3=a*(x3-p)^2+b],[a,b,p])
* Maxima yields the following formula for parabolic interpolation
2 2 2 2
x1 y3 + (x3 - x1 ) y2 - x3 y1
p = ------------------------------------
2 x1 y3 + (2 x3 - 2 x1) y2 - 2 x3 y1
*/
// Scale super-resolution
for (i = 0; i < nb_keypoints; i++) {
CamKeypointShort *keypoint = &keypoints[i];
#if 1
int x = keypoint->x, y = keypoint->y;
int v, max_scale;
max_scale = (y + iROI.srcroi.yOffset) >> 1;
v = (source->height - 1 - (y + iROI.srcroi.yOffset)) >> 1;
if (v < max_scale) max_scale = v;
v = (x + iROI.srcroi.xOffset) >> 1;
if (v < max_scale) max_scale = v;
v = (source->width -1 - (x + iROI.srcroi.xOffset)) >> 1;
if (v < max_scale) max_scale = v;
max_scale -= CAM_SCALE_MARGIN;
if (keypoint->scale < max_scale) {
unsigned int *ptr = ((unsigned int*)(integral->imageData + (y + iROI.srcroi.yOffset) * integral->widthStep)) + iROI.srcroi.xOffset + x;
int scale = keypoint->scale - 1;
int yoffset = scale * widthStep;
int value, num, den, x1, x3, y1, y2, y3;
x1 = -1;
x3 = 1;
y2 = keypoint->value;
CAM_RECURSIVE_PATTERN;
y1 = (value << 4) / (scale * scale);
if (y1 > y2) keypoint->scale <<= 2; // This is a problem : this is not a local maximum in scale...
else {
int found = 0;
scale = keypoint->scale + 1;
do {
yoffset = scale * widthStep;
CAM_RECURSIVE_PATTERN;
y3 = (value << 4) / (scale * scale);
if (y3 <= y2) {
num = (x1 * x1 * y3 + (x3 * x3 - x1 * x1) * y2 - x3 * x3 * y1);
den = x1 * y3 + (x3 - x1) * y2 - x3 * y1;
if (den == 0)
keypoint->scale <<= 2;
else {
int p = (num << 1) / den; // shift only by 1, because den is shifted by 2
keypoint->scale = p + ((scale - 1) << 2);
found = 1;
}
break;
}
y1 = y2;
y2 = y3;
scale++;
} while (scale <= max_scale);
if (!found) keypoint->scale <<= 2;
}
}
else
#endif
keypoint->scale <<= 2;
}
// Angle
if (options & CAM_UPRIGHT) {
for (i = 0; i < nb_keypoints; i++) {
keypoints[i].angle = 0;
}
} else {
camAllocateImage(&filter, CAM_ORIENTATION_STAMP_SIZE, CAM_ORIENTATION_STAMP_SIZE, CAM_DEPTH_16S);
camBuildGaussianFilter(&filter, camSigmaParam);
pnb_keypoints = nb_keypoints;
if (pnb_keypoints > nb_max_keypoints) pnb_keypoints = nb_max_keypoints;
for (i = 0; i < pnb_keypoints; i++) {
nb_keypoints += camKeypointOrientation(source, &keypoints[i], &filter, &keypoints[nb_keypoints]);
}
camDeallocateImage(&filter);
}
// Sort again the features according to value
qsort(keypoints, nb_keypoints, sizeof(CamKeypointShort), camSortKeypointsShort);
// Keypoints allocation
pnb_keypoints = nb_keypoints;
if (pnb_keypoints > nb_max_keypoints) pnb_keypoints = nb_max_keypoints;
if (points->allocated == 0) {
camAllocateKeypoints(points, pnb_keypoints);
} else if (points->allocated < pnb_keypoints) {
camFreeKeypoints(points);
camAllocateKeypoints(points, pnb_keypoints);
}
if (points->bag == NULL) {
#ifdef __SSE2__
points->bag = (CamKeypoint*)_mm_malloc(sizeof(CamKeypoint) * pnb_keypoints, 16);
#else
points->bag = (CamKeypoint*)malloc(sizeof(CamKeypoint) * pnb_keypoints);
#endif
}
for (i = 0; i < pnb_keypoints; i++) {
points->keypoint[i] = &points->bag[i];
points->keypoint[i]->x = keypoints[i].x + iROI.srcroi.xOffset;
points->keypoint[i]->y = keypoints[i].y + iROI.srcroi.yOffset;
points->keypoint[i]->scale = keypoints[i].scale;
points->keypoint[i]->value = keypoints[i].value;
points->keypoint[i]->angle = keypoints[i].angle;
}
points->nbPoints = pnb_keypoints;
free(keypoints);
if (options & CAM_UPRIGHT) {
camKeypointsDescriptor(points, integral, options);
} else {
camKeypointsDescriptor(points, source, options);
}
// Finally, set the points' set
for (i = 0; i < points->nbPoints; i++) {
points->keypoint[i]->set = points;
}
// Integral Image is now useless
camInternalROIPolicyExit(&iROI);
return 1;
}
