A derivativekernel \(h\) in \(x\) has values \(-1\) on the left and \(+1\) on the right. Using the convolution defined in this concept (kernel flipped), what sign does the output have at an edge where intensity rises from left to right?
When convolving, the kernel is flipped and the output is \(f[x-1]-f[x+1]\), negative when intensity rises. With correlation the sign would be positive.
2D convolution is the operation that combines an image \(f(x,y)\) with a kernel \(h(x,y)\) by sliding the kernel and summing products at each position.