image optimizer for web

Pingo (a9) Issues With CMYK JPEG File

Alex said, on 10/02/2022 
Pingo has issues when processing a CMYK color model JPEG file.

Sample File: https://en.wikipedia.org/wiki/File:Channel_digital_image_CMYK_color.jpg

Issue 1: Color Shift
Command: pingo.exe -s9 -strip "Input.jpg"

Issue 2: Image Corruption
Command: pingo.exe -strip "Input.jpg"

I had no issues using just the -s9 or -strip-only program switches.
cédric (dev) said, on 10/02/2022 
1 would not be an issue: the file uses ICC and you asked (-strip) to remove it. 2 should be fixed in a10, thanks
Alex said, on 10/02/2022 
Thank you for all your hard work Cédric. I'll test to verify issue 2 is fixed in Pingo (a10) when I get home from work.

Regarding issue 1, is there currently any way for Pingo to strip all metadata in an image file except important color model information (ICC)? If not, I humbly ask you to add such a feature. It would make my life a whole lot easier :)
cédric (dev) said, on 10/02/2022 
this is what is done if you do not use -strip. in the file you provided, there are 18 xFFE2 markers (ICC); sum of them is > 540KB
an alternative here is to use pingo -auto=N file.jpg, or pingo file.jpg — you will get a smaller sRGB JPEG
Alex said, on 11/02/2022 
Thanks for your explanation. I'll only use the -s9 switch on CYMK JPEG files that I don't want the color model to be removed from.

Regarding issue 2, the JPEG file corruption when only using the -strip command is resolved, but a new issue has surfaced. When only using the -strip command on the CYMK sample JPEG file, the output image is lossy instead of lossless.
cédric (dev) said, on 11/02/2022 
that is expected. you have to use -sN for lossless
Alex said, on 11/02/2022 
Got it. Thanks again for the explanations & for fixing the corruption issue. Your hard work is highly appreciated.

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