[Okular-devel] [Bug 307080] New: PNG image in CBZ wrapper does not display correctly (but PNG iteself does)

[Cory F Cohen]

https://bugs.kde.org/show_bug.cgi?id=307080

            Bug ID: 307080
          Severity: normal
           Version: 0.14.3
          Priority: NOR
          Assignee: okular-devel at kde.org
           Summary: PNG image in CBZ wrapper does not display correctly
                    (but PNG iteself does)
    Classification: Unclassified
                OS: Linux
          Reporter: cfcohen at verizon.net
          Hardware: Ubuntu Packages
            Status: UNCONFIRMED
         Component: Comicbook backend
           Product: okular

This bug report is probably exposing some inconsistency in the library used to
render images between the comic book backend and the default image handling
library.  I would expect the problem to be upstream somewhere, but I have no
idea where. A number of messages such as these are printed to stderr:

QIODevice::read: Called with maxSize < 0
QIODevice::seek: Invalid pos: -6
QImage::scaled: Image is a null image

I'll try to attach a demonstration file if I can figure out where to upload it
to the bug report.

Reproducible: Always

Steps to Reproduce:
I also suspect that the problem is also related to handling of 1-bit deep PNG
images (which have historically had problems in a number of applications that
otherwise support PNG images).  The characteristics of the image are:

$ gm identify -verbose okular-test.png 
Image: okular-test.png
  Format: PNG (Portable Network Graphics)
  Geometry: 2722x3776
  Class: PseudoClass
  Type: bilevel
  Depth: 1 bits-per-pixel component
  Channel Depths:
    Gray:     1 bits
  Channel Statistics:
    Gray:
      Minimum:                     0.00 (0.0000)
      Maximum:                   255.00 (1.0000)
      Mean:                      251.17 (0.9850)
      Standard Deviation:         31.02 (0.1216)
  Colors: 2
    0: (  0,  0,  0)      black
    1: (255,255,255)      white
  Resolution: 72x72 pixels
  Filesize: 38.2K
  Interlace: No
  Orientation: Unknown
  Background Color: black
  Border Color: #DFDFDF
  Matte Color: #BDBDBD
  Compose: Over
  Dispose: Undefined
  Iterations: 0
  Compression: Zip
  Comment:  generated by unpaper

  Create-date: 2008-04-02T20:07:08-04:00
  Modify-date: 2008-04-02T20:07:08-04:00
  Signature: ba1078561438738723d855335e97b5f0745cb53153d9f75697b06ae5c2fd6dee
  Tainted: False
  User Time: 0.070u
  Elapsed Time: 0:01
  Pixels Per Second: 326.7M

Actual Results:  
The page just display with the Okular icon.

Expected Results:  
The actual image.

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