Hi Fred, I tried it out, but for me, it doesnt find conv() in package cuda_ndarray gpuval = cuda_ndarray.conv(img, kern, mode, subsample). So, made the changes in the test_conv_cuda_ndarray _test_dummy().

I see that the cpu version is computed using py_conv(), which in turn calls scipy.signal.convolve2d. How can the result 'gpuval' now be the same as scipy.signal.convolve2d instead of the scipy.signal.correlate?

Also, this still passes tests for all image, kernel, channel and batch sizes: https://github.com/stencilman/Theano-1/blob/fb66035292ef070b86466bf61c9c42b8faaa0a1c/theano/sandbox/cuda/tests/test_conv_gemm.py