Binary file formats
JPEG lossless crop alignment
Align a crop’s upper-left corner to JPEG MCU boundaries.
Your inputs
Start with an exampleYour result
Example resultAa — A small example of your colors.
How it works
Move the crop origin up/left to its MCU boundary. Expand width and height to preserve the requested right and bottom edges.
A 100×100 crop at (17,17) in 4:2:0 expands to 101×101 at (16,16).
Limits
Uses the selected common sampling layout, not a parsed JPEG. No transform is executed; verify the image’s actual MCU configuration before using the command.