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gfl + jpeg2000 + changing quality

Posted: Sun Mar 11, 2007 10:09 am
by stolarz
hi people, i'm using the jpeg 2000 plugin with the gfl library and i don't know how to change the quality when compressing to this format. i'm using gflSaveBitmapIntoMemory() and filling GFL_SAVE_PARAMS structure. been trying to modify the Quality member but it seems that it works for regular jpegs only. can anyone help me?

Re: gfl + jpeg2000 + changing quality

Posted: Tue Mar 13, 2007 2:26 pm
by xnview
stolarz wrote:hi people, i'm using the jpeg 2000 plugin with the gfl library and i don't know how to change the quality when compressing to this format. i'm using gflSaveBitmapIntoMemory() and filling GFL_SAVE_PARAMS structure. been trying to modify the Quality member but it seems that it works for regular jpegs only. can anyone help me?
Quality doesn't change anything????

:(

Posted: Wed Mar 14, 2007 8:37 pm
by stolarz
:( you are right... i tested it once again, the results differ. it is 1288438 bytes for quality 95 and 99025 bytes for quality 5. i haven't noticed that fact before cause i was using gflSaveBitmapIntoMemory. But what worries me most is why i thought Quality parameter doesn't change anything - i was compressing the picture with quality 95 and 5 and they both lasted 10 seconds...

lossless

Posted: Wed Mar 14, 2007 10:53 pm
by stolarz
btw, is there any lossless compression in gfl? like lossless jpeg? i see there is GFL_LZW for tiff. any other?

Re: lossless

Posted: Thu Mar 15, 2007 7:38 am
by xnview
stolarz wrote:btw, is there any lossless compression in gfl? like lossless jpeg? i see there is GFL_LZW for tiff. any other?
All format like tiff, png, bmp are lossless