jpegtran lossless rotation?
Hello. I'm a bit confused. jpegtran is supposed to provide lossless
transformation on jpg files. Understanding nothing about the internals of
graphic formats, I'd expect that original and transformed files had the same
number of bytes. However, if I apply it to some file from my digital camera,
jpegtran -rotate 90 -copy all pict0069.jpg > l.jpg
-rw-r--r-- 1 vmunoz vmunoz 436513 Jan 24 19:06 l.jpg
-r--r--r-- 1 vmunoz vmunoz 440635 Jan 24 18:39 pict0069.jpg
which is almost the same. Does anybody know where do the 'lost' bytes belong
to? Exif data? I checked 'exif l.jpg', and 'exif pict0069.jpg', and
the output is exactly the same.
I know I'm being obsessive, but does anyone know?