In my
"Plain C Resampling DLL", following Libor Tinka's (
"Image Resizing - outperform GDI+") approach, I discarded the out-of-border contributions in the weighted sum, i.e. something like:
for (j = left; j<= right; j++)
{
if ( j < 0 || j >= iw) continue;
weight = (*pFnFilter)( (center - j) * FILTER_FACTOR);
if (weight == 0.0) continue;
n = h_count[i];
p_pixel[n] = j;
p_weight[n] = weight;
h_wsum[i] += weight;
h_count[i]++;
}
:)