Re: [Jpeg-users] libjpeg 6c ?

[paul v. d. b. <pau...@gm...>]

On Wed, 26 Nov 2008 21:05:33 +0100
Bill Allombert <Bil...@ma...> wrote:

> Is it an official libjpeg release ? 
> Should I upgrade the Debian package to it ?
> What are the changes ?
 
I have followed http://jpegclub.org/libjpeg-6c.tar.gz for some time.
It is a moving target. I have at least 4 different versions, 2 from 2006
and 2 from 2008. 

The most important changes from the original ijg-release are:

cjpeg -h adds:
  -scale M/N     Scale image by fraction M/N, eg, 1/2

djpeg -h adds:
  -scale M/N     Scale output image by fraction M/N, eg, 1/8

jpegtran -h adds:
  -crop WxH+X+Y  Crop to a rectangular subarea 
[ this is already included in debian, gentoo, suse ..? ]

But if you run 'make -i test' on the 6c source with testimages 
from ijg-source you get:

./djpeg -dct int -ppm -outfile testout.ppm  ./testorig.jpg
./djpeg -dct int -bmp -colors 256 -outfile testout.bmp  ./testorig.jpg
./cjpeg -dct int -outfile testout.jpg  ./testimg.ppm
./djpeg -dct int -ppm -outfile testoutp.ppm ./testprog.jpg
./cjpeg -dct int -progressive -opt -outfile testoutp.jpg ./testimg.ppm
./jpegtran -outfile testoutt.jpg ./testprog.jpg
cmp ./testimg.ppm testout.ppm
./testimg.ppm testout.ppm differ: byte 37, line 4
make: [test] Error 1 (ignored)
cmp ./testimg.bmp testout.bmp
./testimg.bmp testout.bmp differ: byte 59, line 1
make: [test] Error 1 (ignored)
cmp ./testimg.jpg testout.jpg
./testimg.jpg testout.jpg differ: byte 1395, line 7
make: [test] Error 1 (ignored)
cmp ./testimg.ppm testoutp.ppm
./testimg.ppm testoutp.ppm differ: byte 37, line 4
make: [test] Error 1 (ignored)
cmp ./testimgp.jpg testoutp.jpg
./testimgp.jpg testoutp.jpg differ: byte 1582, line 8
make: [test] Error 1 (ignored)
cmp ./testorig.jpg testoutt.jpg


Regards, Paul