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

              blocks

              Bug - A problem which impairs or prevents the functions of the product. PDF-289 Transparency grouping on colour space support

              • Major - Major loss of function.
              • Closed

              Bug - A problem which impairs or prevents the functions of the product. PDF-373 Error clipping or specifying alpha in jpeg encoded images.

              • Major - Major loss of function.
              • Closed

              Bug - A problem which impairs or prevents the functions of the product. PDF-417 Loss of color on generated images

              • Major - Major loss of function.
              • Closed

                Activity

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                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
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                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
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                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
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                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
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                Patrick Corless added a comment -

                needs more work...

                Show
                Patrick Corless added a comment - needs more work...
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                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
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                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:
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                    Dates

                    • Created:
                      Updated: