CUDA SDK Histogram Results Order

Hello,

I am using CUDA SDK’s histogram256 function to calculate a 256 bin histogram. For example the histogram I want to get is like this:

0 234 0 2 34 345 0 0 4 …

But SDK’s histogram function gives me the results like below:

234 2 34 345 4 0 0 0 0 …

which means this code only puts the bins which have value bigger than zero to an array. But I need to get all the bins. Is there a way to deactivate the rearrangement of bins?

Thank you.

I am unaware of this problem with the SDK’s histogram code. You can have a look at the histogram whitepaper written by V. Podlozhnyuk, which provides some details about the implementation is the SDK: http://developer.download.nvidia.com/compute/cuda/1_1/Website/projects/histogram256/doc/histogram.pdf
Maybe that will help you to understand the code and repair the problem.

Otherwise, you could also try out a new method of histogramming, which is presented on the website:
http://parse.ele.tue.nl/research/tools (scroll down to the bottom)
It will probably not contain the same bug and might give you a speed increase, but might be a little trickier to get working for arbitrary inputs, as it is part of a research project.