for (line1, line2) in data1[pic1.get_offset(comp)..].chunks(pic1.get_stride(comp)).zip(
data2[pic2.get_offset(comp)..].chunks(pic2.get_stride(comp))).take(h) {
for (&pix1, &pix2) in line1[..w].iter().zip(line2.iter()) {
for (line1, line2) in data1[pic1.get_offset(comp)..].chunks(pic1.get_stride(comp)).zip(
data2[pic2.get_offset(comp)..].chunks(pic2.get_stride(comp))).take(h) {
for (&pix1, &pix2) in line1[..w].iter().zip(line2.iter()) {