image.convolve(src,dst,kernel) performs a convolution on the Tensor src Tensor dst. The convolution uses the Tensor kernel to perform the convolution.

image.convolve(src,nil,kernel) performs the same as above, except it creates a destination Tensor the same size as src and returns it.

image.convolve(src,kernel,pad_const) performs a convolution on the Tensor src and stores the result in-place. The convolution uses the Tensor kernel to perform the convolution. A constant value pad_const is placed around the edges of src so that dst is the same size as src.