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https://issues.apache.org/jira/browse/PDFBOX-2681?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Jon Wu updated PDFBOX-2681:
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    Attachment: photo-rectangle-overlay-opacity-30.pdf
                photo-rectangle-overlay-opacity-30-photoshop-comparison.jpg

> Colors inaccurate rastered CMYK source w/ gradient + photo
> ----------------------------------------------------------
>
>                 Key: PDFBOX-2681
>                 URL: https://issues.apache.org/jira/browse/PDFBOX-2681
>             Project: PDFBox
>          Issue Type: Bug
>          Components: Rendering
>    Affects Versions: 2.0.0
>         Environment: Tested on OS X 10.10, Java 1.6 / 1.8
>            Reporter: Jon Wu
>         Attachments: Shading2Function2CMYK.pdf, Shading2Function2CMYK.ps, 
> acrobat-vs-pdfbox-swop.png, gradient-test-illustrator.jpg, 
> gradient-test-pdfbox.jpg, gradient-test-photo-illustrator.jpg, 
> gradient-test-photo-pdfbox-us-web-coated-swop-v2.jpg, 
> gradient-test-photo-pdfbox.jpg, gradient-test-photo-rgb-illustrator.jpg, 
> gradient-test-photo-rgb-pdfbox.jpg, gradient-test-photo-rgb.pdf, 
> gradient-test-photo.pdf, gradient-test.pdf, 
> photo-rectangle-overlay-opacity-30-photoshop-comparison.jpg, 
> photo-rectangle-overlay-opacity-30.pdf, purple-gradient-comparison.jpg
>
>
> In the attached gradient-test-photo.pdf, there's a photo with a gradient on 
> top of it. The colors in the gradient are CMYK. When rasterizing this test 
> file with PDFBox 2.0.0 SNAPSHOT 20150209, the resulting image's gradient is 
> different from the original and the colors of the photo under the gradient 
> look significantly different vs the display in Adobe tools like Illustrator 
> or other compliant PDF readers.
> Issues:
> - Color hue is wrong. Is this a CMYK to RGB issue?
> - Opacity of gradient is wrong and much different. The jpg from Illustrator 
> shows much more of the photo without a gradient over it.
> Without a photo, there's still a difference, but it's much harder to see. 
> Example in gradient-test.pdf where the same gradient is drawn over a grey 
> rectangle.
> If I convert the PDF to RGB in Illustrator first and rasterize the RGB PDF 
> with PDFBox, the result is nearly identical between Illustrator and PDFBox so 
> this seems like a CMYK conversion issue in both the general color conversion 
> and maybe how the gradient is calculated.



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