CgJPEGFileFormat>formatMatchesByteStream: fails for JPG file

[PhotonDemon]

Hi,

I'm trying to use CgFileFormat formatMatchingFile: aFilePath ifNone: [] to determine the CgImageFileFormat sub class to use to read an image file. When the image is a JPEG file, CgFileFormat>formatMatchingFile:ifNone: fails to fine the CgImageFileFormat sub class of CgJPEGFileFormat .

The problems seems to be in CgJPEGFileFormat>formatMatchesByteStream: at:

Code: Select all

   (appn verify and: [appn segmentMarker == APP0])
      ifFalse: noMatch.


The test for "appn segmentMarker == APP0" looks like the problem as APP0 is 16rFFE0 and the file contains 16rFFE1. The thing is I am able to read and display the file with CgJPEGFileFormat, just fine. Every jpg file I've tried fails the test but is able to be read and displayed.

Is this a bug or am I missing something?

Lou

[marten]

And 16rFFE1 corresponds to APP1 - another subdefinition within the JPEG specification.

Perhaps you might read here ...

http://search.cpan.org/dist/Image-MetaData-JPEG/lib/Image/MetaData/JPEG.pod#JFIF_data_%28%22APP0%22_segments%29

or

http://en.wikipedia.org/wiki/JPEG