Legacy ImageMagick Discussions Archive

Hi, all. I would like to propose QBRA (Quantize Bulk Reduce Acceleration) configuration to enable rapid color reduction. The explanation of idea is here. - http://d.hatena.ne.jp/yoya/20130724/im With only a small code addition and without changing the fundamental algorithm we can get a performance ...

Thank you for your quick response. At 6.8.6-5, this modified code has wrong calculation. node_info->quantize_error+=count*sqrt((double) (error.red*error.red+ count*error.green*error.green+count*error.blue*error.blue+ count*error.opacity*error.opacity)); In sqrt all count multiplication must be ...

I found tree walking mistake for RiemersmaDither function. * ImageMagick-6.8.6-4/magick/quantize.c /* Identify the deepest node containing the pixel's color. */ node_info=p->root; for (index=MaxTreeDepth-1; (ssize_t) index > 0; index--) { id=ColorToNodeId(cube_info,&pixel,index); if (node_info ...

quantize_error summarization has been changed at 6.4.1-3 * magick/quantize.c - 6.4.1-2 node_info->quantize_error+=sqrt((double) (error.red*error.red+ error.green*error.green+error.blue*error.blue+error.opacity* error.opacity)); - 6.4.1-3 if (IsColorSimilar(image,p,p+count) == MagickFalse) break ...