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https://issues.apache.org/jira/browse/PDFBOX-1893?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13906633#comment-13906633
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Fred Hansen commented on PDFBOX-1893:
-------------------------------------
By localizing code, I hope this makes it easier to navigate away from awt for
Android.
> Refactor color spaces
> ---------------------
>
> Key: PDFBOX-1893
> URL: https://issues.apache.org/jira/browse/PDFBOX-1893
> Project: PDFBox
> Issue Type: Improvement
> Components: Rendering
> Affects Versions: 2.0.0
> Reporter: John Hewson
> Assignee: John Hewson
> Labels: color
> Fix For: 2.0.0
>
>
> I'm currently working on this, so I wanted to open an issue to let everyone
> know.
> Color spaces need to be refactored in 2.0.0. Tilman noticed slowness in
> PDFBOX-1851 due to using ICC profiles and calling ColorSpace#toRGB for every
> pixel. For example, the file from PDFBOX-1851 went from rendering in 4
> seconds to taking over 60 seconds.
> The solution is to use ColorConvertOp to convert an entire BufferedImage in
> one go, taking advantage of AWT's native color management module. Color
> conversions done this way are almost instantaneous, even for large images.
> The current design of color spaces within PDFBox depends upon conversions
> being done on a per-pixel basis, so a significant refactoring is needed in
> order to convert images using ColorConvertOp without having to resort to
> per-pixel calls in cases such as a Separation color space which uses a CMYK
> alternate color space via a tint-transform.
> The color space handling code is also tightly coupled to image handling. The
> various classes which read images each have their own color handling code
> which rely on per-pixel conversions. For this reason any color space
> refactoring must also included a significant refactoring of image handling
> code. This is an opportunity to refactor all color handling so that it is
> encapsulated within the color space classes, allowing downstream users to
> call toRGB(float[]) or toRGB(BufferedImage) and not need to worry about tint
> transforms and the like.
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