On Mon, 2005-01-24 at 19:18 +0900, Victor Munoz wrote: > 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, > the command: > > jpegtran -rotate 90 -copy all pict0069.jpg > l.jpg > > yields: > > -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? That 1% difference in file size probably has to do with how it encodes different patterns of colors and intensities. -- ----------------------------------------------------------------- Ron Johnson, Jr. Jefferson, LA USA PGP Key ID 8834C06B I prefer encrypted mail. 296,443 sq mi (767,787 sq km) are needed for 6 billion people to live at the same population density as Manhattan, New York. That is ~ Arizona or Nevada. Alternatively, that ~ double the size of Japan or Zimbabwe
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