OpenCV 2.3.1 stitching module GPU?
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I've been trying the stitching module in OpenCV recently but I'm having some problems.

There are many parameters for users to tune. Two of them are "preview" and "try_gpu".

According to the instruction in the code:

        "  --preview\n"
        "      Run stitching in the preview mode. Works faster than usual mode,\n"
        "      but output image will have lower resolution.\n"
        "  --try_gpu (yes|no)\n"
        "      Try to use GPU. The default value is 'no'. All default values\n"
        "      are for CPU mode.\n"

Both of their default values are "false". I set them to be "true" so as to make use of GPU to deal with part of the algorithms involved in the program and then I ran the program with the other parameters unchanged, whereas the result wasn't even much quicker than that with all parameters left default. The whole program takes about 5 seconds to stitch two pictures with a resolution of 500x375.
Even though I switched the 2 parameters mentioned above to be "true", it still takes roughly 5 seconds to finish the whole step.

I know that Nvidia has been supporting CUDA for OpenCV for a long time... The Graphic card I use is GTX 460, which is supposed to have CUDA.

I was expecting that by setting Try_gpu = true would make the program run faster, but the outcome didn't seem to be that way.

Did I misunderstand something or is there any other settings involed and I missed them?


Thanks for all the helps in advance.