There's a fairly common use case for resizing where you have a large image already in CPU memory, and want to create a thumbnail or otherwise downsize. Copying

There's a fairly common use case for resizing where you have a large image already in CPU memory, and want to create a thumbnail or otherwise downsize. Copying the large source image to GPU memory can be expensive enough that it's faster to simply do the resize on the CPU, since the data is already there.