float getMedian(float arr[], int n)
{
float *temP = (float *) malloc(sizeof(float) * n);
// int i;
// for (i = 0; i < n; i++)
// {
// temP[i] = arr[i];
// }
memcpy(temP, arr, sizeof(float) * n);
float median;
median = getMedianUnmanaged(temP, n);
free(temP);
return median;
}
/**
* Calculates the new (moved and resized) Bounding box.
* Calculation based on all relative distance changes of all points
* to every point. Then the Median of the relative Values is used.
*/
int predictbb(float *bb0, CvPoint2D32f *pt0, CvPoint2D32f *pt1, int nPts,
float *bb1, float *shift)
{
float *ofx = (float *) malloc(sizeof(float) * nPts);
float *ofy = (float *) malloc(sizeof(float) * nPts);
int i;
int j;
int d = 0;
float dx, dy;
int lenPdist;
float *dist0;
float *dist1;
float s0, s1;
for(i = 0; i < nPts; i++)
{
ofx[i] = pt1[i].x - pt0[i].x;
ofy[i] = pt1[i].y - pt0[i].y;
}
dx = getMedianUnmanaged(ofx, nPts);
dy = getMedianUnmanaged(ofy, nPts);
free(ofx);
ofx = 0;
free(ofy);
ofy = 0;
//m(m-1)/2
lenPdist = nPts * (nPts - 1) / 2;
dist0 = (float *) malloc(sizeof(float) * lenPdist);
dist1 = (float *) malloc(sizeof(float) * lenPdist);
for(i = 0; i < nPts; i++)
{
for(j = i + 1; j < nPts; j++, d++)
{
dist0[d]
= sqrt(pow(pt0[i].x - pt0[j].x, 2) + pow(pt0[i].y - pt0[j].y, 2));
dist1[d]
= sqrt(pow(pt1[i].x - pt1[j].x, 2) + pow(pt1[i].y - pt1[j].y, 2));
dist0[d] = dist1[d] / dist0[d];
}
}
//The scale change is the median of all changes of distance.
//same as s = median(d2./d1) with above
*shift = getMedianUnmanaged(dist0, lenPdist);
free(dist0);
dist0 = 0;
free(dist1);
dist1 = 0;
s0 = 0.5 * (*shift - 1) * getBbWidth(bb0);
s1 = 0.5 * (*shift - 1) * getBbHeight(bb0);
//Apply transformations (translation& scale) to old Bounding Box
bb1[0] = bb0[0] - s0 + dx;
bb1[1] = bb0[1] - s1 + dy;
bb1[2] = bb0[2] + s0 + dx;
bb1[3] = bb0[3] + s1 + dy;
//return absolute scale change
// shift[0] = s0;
// shift[1] = s1;
return 1;
}