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IPP SAMPLES / IJL / Poor color conversion in YCCK color space

wesson
Beginner
855 Views
Hello,
imho there is an issue with JPEG containing YCrCbA color spaces.

When such JPEG are handled by IJL, the rendered colors seems to be wrong.

the image is exagerately colored, some burned colors stains may occur.

The same JPEG file loaded with The Gimp or Adobe Photoshop give a result that looks much more natural.

I've attached an image representing the issue. Left image is OK, right image is what IJL decodes.

Conversion from YCrCbA to CYMK is done with ippiYCCK444ToCMYKLS_MCU_16s8u_P4C4R,
and conversion from CYMK to RGB is done with the following formula, derivated of the IPPI Manual page 15-17

Cyan = pDst[0];
Magenta = pDst[1];
Yellow = pDst[2];
Key = pDst[3];

R = Cyan * Key / 255;
G = Magenta * Key / 255;
B = Yellow * Key / 255;

Anyone has a clue ? I can provide the full sized source image, it's a huge JPEG file (25 megs - 4080*5440)

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Vladimir_Dudnik
Employee
855 Views

Hello,

it would be nice if you can provide original JPEG file. By the way, could you please try the same image with other IPP JPEG samples (JPEGView or IJG optimized with IPP)?

Regards,
Vladimir

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mr_h_
Beginner
855 Views

Hi,

do you have ijl.lib(X64)?

can you send me? thanks 

my email:493820802@qq.com

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