Could you explain more about the “usual” format? I.e. does a specific library return volumes as HWD or is there any other convention? I’m currently seeing it more as CHW (PIL) vs. HWC (OpenCV), which might be annoying sometimes but both memory layouts have certain advantages. I’m not sure what the advantage of HWD vs. DHW would be. E.g. is there any expected performance gain using your layout?