ICEpdf
  1. ICEpdf
  2. PDF-39

Colors in ICEpdf differ slightly from those of Abode

    Details

    • Type: Bug Bug
    • Status: Closed
    • Priority: Major Major
    • Resolution: Duplicate
    • Affects Version/s: 3.0, 4.0.1
    • Fix Version/s: 4.1.3
    • Component/s: Core/Parsing
    • Labels:
      None
    • Environment:
      ICEpdf 2.7.1

      Description

      The main text of the document is using cmyk and when using the alternative2 ->
      rgb algorithm is a pretty close match to what adobe is generating. However the
      Images uses an indexed cmyk colour space which seem to map correctly however we
      see heavy greens on some of the images. I've done some tracing and can't find
      anything that is out of place.

      I suspect there is something incorrect in how we apply the colour profile when
      building the image in Stream.makeImageWithRasterFromBytes.
      1. 7226.pdf
        494 kB
        Tyler Johnson

        Activity

        Tyler Johnson created issue -
        Tyler Johnson made changes -
        Field Original Value New Value
        Salesforce Case [50070000007C5bp]
        Ken Fyten made changes -
        Fix Version/s 3.1 [ 10181 ]
        Assignee Priority P2
        Assignee Patrick Corless [ patrick.corless ] Mark Collette [ mark.collette ]
        Hide
        Mark Collette added a comment -

        The Stream class has its own CMYK -> RGB conversion algorithm, which we could try replacing with Patrick's alternative2 algorithm. The existing algorithm is not an actual spec one, but is derived from a spec, but modified because certain CMYK image PDF cases were quite different in the brightness/lightness. Potentially there might be some gamma value or rendering intent that should be used to affect the CMYK conversion.

        Show
        Mark Collette added a comment - The Stream class has its own CMYK -> RGB conversion algorithm, which we could try replacing with Patrick's alternative2 algorithm. The existing algorithm is not an actual spec one, but is derived from a spec, but modified because certain CMYK image PDF cases were quite different in the brightness/lightness. Potentially there might be some gamma value or rendering intent that should be used to affect the CMYK conversion.
        Patrick Corless made changes -
        Fix Version/s 3.2 [ 10212 ]
        Fix Version/s 3.1 [ 10181 ]
        Affects Version/s 3.0 [ 10180 ]
        Ken Fyten made changes -
        Fix Version/s 4.0 - Beta [ 10212 ]
        Assignee Priority P2
        Tyler Johnson made changes -
        Attachment 7226.pdf [ 12381 ]
        Tyler Johnson made changes -
        Affects Version/s 4.0.1 [ 10228 ]
        Ken Fyten made changes -
        Fix Version/s 4.1 [ 10227 ]
        Patrick Corless made changes -
        Fix Version/s 4.1.1 [ 10244 ]
        Fix Version/s 4.1 [ 10227 ]
        Patrick Corless made changes -
        Fix Version/s 4.2 [ 10243 ]
        Fix Version/s 4.1.1 [ 10244 ]
        Patrick Corless made changes -
        Assignee Mark Collette [ mark.collette ] Patrick Corless [ patrick.corless ]
        Hide
        Patrick Corless added a comment -

        This issue was actually more related to CYYK to RGB. Some work was done on this issue for 4.1.3 for a client patch. This is a very difficult task to get correct as there is some colour loss when going from a subtractive to an additive colour model.

        Duplicate of PDF-247

        Show
        Patrick Corless added a comment - This issue was actually more related to CYYK to RGB. Some work was done on this issue for 4.1.3 for a client patch. This is a very difficult task to get correct as there is some colour loss when going from a subtractive to an additive colour model. Duplicate of PDF-247
        Patrick Corless made changes -
        Status Open [ 1 ] Resolved [ 5 ]
        Fix Version/s 4.1.3 [ 10257 ]
        Fix Version/s 4.2 [ 10243 ]
        Resolution Duplicate [ 3 ]
        Ken Fyten made changes -
        Status Resolved [ 5 ] Closed [ 6 ]

          People

          • Assignee:
            Patrick Corless
            Reporter:
            Tyler Johnson
          • Votes:
            0 Vote for this issue
            Watchers:
            0 Start watching this issue

            Dates

            • Created:
              Updated:
              Resolved: