let dst = &mut dst[doff..];
let src = &src[EDGE_PRE + EDGE_PRE * sstride..];
for (out, src) in dst.chunks_mut(dstride).take(size).zip(src.chunks(sstride)) {
let dst = &mut dst[doff..];
let src = &src[EDGE_PRE + EDGE_PRE * sstride..];
for (out, src) in dst.chunks_mut(dstride).take(size).zip(src.chunks(sstride)) {