color of reconstructed png file much darker

[moha23]

I tried compressing and decompressing an image from the kodak dataset (kodim01.png) but the reconstruction seems much darker no matter what psnr value i give/dont give at all.
Commands I used:

/home/mo/Documents/openjpeg-v2.4.0-linux-x86_64/bin/opj_compress -i /home/mo/Downloads/kodim01.png -o /home/mo/Downloads/kodim01.jp2
/home/mo/Documents/openjpeg-v2.4.0-linux-x86_64/bin/opj_decompress -i /home/mo/Downloads/kodim01.jp2 -o /home/mo/Downloads/kodim01recons.png

Is this expected behaviour or am i doing something wrong? When I check the psnr manually it's much lower than what I put in the command.

[moha23]

Oh great! Yeah I tried on a couple other images and it works just fine so figured must be some gamma issue. Thanks a lot for getting back with this detailed info! Just wanted to check out the rate distortion curve for Kodak dataset available online and widely used in research papers. Thanks again.

[jiuzhuanzhuan]

Oh great! Yeah I tried on a couple other images and it works just fine so figured must be some gamma issue. Thanks a lot for getting back with this detailed info! Just wanted to check out the rate distortion curve for Kodak dataset available online and widely used in research papers. Thanks again.

Hi，
Did you get the correct R-D loss of Kodak compressed with OPENJPEG ? When I try to compress Kodak lossly，command as below

opj_compress -i  kodim01.png  -q  xx  -o kodim01.jp2
opj_decompress -i  kodim01.jp2 -o kodim01recons.png

the parameters of q from set of [20,25,30,35,40,45,50].
But the compression rate of OPENJPEG even bad then jpeg. Did you know how to use OPENJPEG correctly?