ICEpdf
  1. ICEpdf
  2. PDF-350

Enhance transparency groups implementation to avoid loss of render quality.

    Details

    • Type: Improvement Improvement
    • Status: Reopened
    • Priority: Major Major
    • Resolution: Unresolved
    • Affects Version/s: 4.2.2
    • Fix Version/s: None
    • Component/s: Core/Parsing
    • Labels:
      None
    • Environment:
      any

      Description

      A few releases ago basic support for transparency group support was added. Mainly transparency support for a group of shapes and knockouts.

      The current implementation will detect a transparency group flag on the form object. If detected painting is deferred and the shapes painted to image so that a transparency group can be applied. The problem with this approach is that image will look blurred as document zoom is applied.

      It may be possible to spawn a new graphics context with g2d.createGraphics() in a similar but alternative means to creating the image. A little bit of research needs to be done here.

        Issue Links

          Activity

          Hide
          Patrick Corless added a comment -

          I've been working on an over fix for transparency group support and soft masking for groups. Still a lot of work to do, moving out to 5.0.

          Show
          Patrick Corless added a comment - I've been working on an over fix for transparency group support and soft masking for groups. Still a lot of work to do, moving out to 5.0.
          Hide
          Patrick Corless added a comment -

          A user on the forms has also reported the render quality issue. Pretty sure I should remove the code in question. http://jforum.icesoft.org/JForum/posts/list/0/20778.page

          Show
          Patrick Corless added a comment - A user on the forms has also reported the render quality issue. Pretty sure I should remove the code in question. http://jforum.icesoft.org/JForum/posts/list/0/20778.page
          Hide
          Patrick Corless added a comment -

          I've reverted the xform code back to standard drawing with out the back buffer. This addresses the quality issues, further work will be done to try a different approach to achieving transparency groups effects.

          Show
          Patrick Corless added a comment - I've reverted the xform code back to standard drawing with out the back buffer. This addresses the quality issues, further work will be done to try a different approach to achieving transparency groups effects.
          Hide
          Patrick Corless added a comment -

          attached the wrong bug for this case. Updated ContentParser and Shapes in rev 28864.

          Show
          Patrick Corless added a comment - attached the wrong bug for this case. Updated ContentParser and Shapes in rev 28864.
          Hide
          Patrick Corless added a comment -

          needs more work...

          Show
          Patrick Corless added a comment - needs more work...
          Hide
          Patrick Corless added a comment -

          Transparency groups have been reworked a bit in 4.3.3 but the implementation in general needs quite a bit more work. The PDF in question can be rendered at full quality if the system property -Dorg.icepdf.core.disableTransparencyGroup=true.

          Show
          Patrick Corless added a comment - Transparency groups have been reworked a bit in 4.3.3 but the implementation in general needs quite a bit more work. The PDF in question can be rendered at full quality if the system property -Dorg.icepdf.core.disableTransparencyGroup=true.
          Hide
          Patrick Corless added a comment -

          Our smak algorithm as been improved to do a better job of blending alpha. Further work is need to explore if the matte entry can be used to properly decode this.

          Show
          Patrick Corless added a comment - Our smak algorithm as been improved to do a better job of blending alpha. Further work is need to explore if the matte entry can be used to properly decode this.

            People

            • Assignee:
              Patrick Corless
              Reporter:
              Patrick Corless
            • Votes:
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              Watchers:
              1 Start watching this issue

              Dates

              • Created:
                Updated: