static void zoom(int keycode, t_env *env)
{
if (keycode == KEYCODE_PLUS)
apply_zoom(env, ZOOM_IN);
else if (keycode == KEYCODE_MINUS)
apply_zoom(env, ZOOM_OUT);
if (keycode == KEYCODE_ARROW_UP)
env->iter_max += 20;
else if (keycode == KEYCODE_ARROW_DWN && env->iter_max > 20)
env->iter_max -= 20;
}
void compute_sift_keypoints(float *input, keypointslist& keys, int width, int height, siftPar &par)
{
flimage image;
/// Make zoom of image if necessary
float octSize = 1.0f;
if (par.DoubleImSize){
//printf("... compute_sift_keypoints :: applying zoom\n");
image = alloc_image<float>(2*width, 2*height);
apply_zoom(input,image.data,2.0,par.order,width,height);
octSize *= 0.5f;
} else
image = alloc_image( make_image(input,width,height) );
/// Apply initial smoothing to input image to raise its smoothing to par.InitSigma.
/// We assume image from camera has smoothing of sigma = 0.5, which becomes sigma = 1.0 if image has been doubled.
/// increase = sqrt(Init^2 - Current^2)
float curSigma=0.5f;
if (par.DoubleImSize) curSigma *= 2.0f;
if (par.InitSigma > curSigma ) {
if (DEBUG) printf("Convolving initial image to achieve std: %f \n", par.InitSigma);
float sigma = (float)sqrt(par.InitSigma*par.InitSigma -
curSigma*curSigma);
gaussian_convolution(image.data, image.data, image.w, image.h, sigma);
}
/// Convolve by par.InitSigma at each step inside OctaveKeypoints by steps of
/// Subsample of factor 2 while reasonable image size
/// Keep reducing image by factors of 2 until one dimension is
/// smaller than minimum size at which a feature could be detected.
int minsize = 2 * par.BorderDist + 2;
//printf("... compute_sift_keypoints :: maximum number of scales : %d\n", par.OctaveMax);
for(int i=(par.DoubleImSize?-1:0);
i<=par.OctaveMax && image.w>minsize && image.h>minsize;
i++) {
if(DEBUG) printf("Calling OctaveKeypoints \n");
OctaveKeypoints(image, octSize, keys,par);
// image is blurred inside OctaveKeypoints and therefore can be sampled
flimage aux = alloc_image<float>(image.w/2, image.h/2);
if(DEBUG) printf("Sampling initial image \n");
sample(image.data, aux.data, 2.0f, image.w, image.h);
free(image.data);
image = aux;
octSize *= 2.0f;
}
free(image.data);
/* printf("sift:: %d keypoints\n", keys.size());
printf("sift:: plus non correctly localized: %d \n", par.noncorrectlylocalized);*/
}