Tag: nvidia performance primitives

CImg and NVIDIA’s NPP Interop

Apparently, NPP relies on the pixel order of its input arrays (they need to be interleaved). If you are planning on using CImg with NPP, be sure to check this post out before attempting to do so. Failing to permute CImg image axes will result in wrong filtered values for color images.

NPP’s Convoluion with Border Control Only Partially Implemented

One thing I discovered yesterday is that the image convolution filters implemented in NPP (such as nppiFilterBorder_8u) are only partially implemented! These family of functions are asserted to provide border control for the convolution, thus serving as a robust alternative to the regular image convolution functions in NPP (such as nppiFilter_8u). The catch is that the …

Continue reading

NPP’s Box Filter (nppiFilterBox) is Broken

Surprisingly, the box filter function (nppiFilterBox_8u)  that is shipped with CUDA as a part of the NPP library is broken! It is the same function that is used in the “Box Filter with NPP” sample. If you import this sample from the CUDA SDK and try it with masks of size 13 an above, the filter …

Continue reading