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jpegtran -crop WxH+X+Y photo.jpg > cropped.jpg The upper left corner of the result has to be on a compression block boundary. Those blocks are 8x8, but the Cb
by tropo 7y ago
jpegtran -crop WxH+X+Y photo.jpg > cropped.jpg
The upper left corner of the result has to be on a compression block boundary. Those blocks are 8x8, but the Cb and Cr channels may be half resolution and thus 16x16 in your image.