[OpenJDK 2D-Dev] 6523398: sun.java2d.cmm.lcms.LCMS.setTagData

[Dmitri Trembovetski]

   Hi Keith,

   thanks for looking into this.

   I suspect that the problem is with the GRAY.pf profile
   which came with openjdk. I believe Alexey who worked on
   this stuff generated it himself and might have made
   a mistake or the file got mangled later somehow
   (may be during mercurial conversion or something).

   According to this bug:
     6523402: OSS CMM: Some quality problems with GRAY, PYCC and CIEXYZ color spaces with lcms library
   it should have worked with GRAY profile (albeit with some
   quality issues).

   Thanks,
     Dmitri

Keith Seitz wrote:
> Hi,
> 
> I've been working on fixing this bug, and while it is clear that LCMS 
> was never written to do this, it can be made to work. I've got a patch 
> that passes the JCK tests in this area.
> 
> While writing jtreg tests for this, though, I've stumbled across 
> something odd, and I was hoping that someone on this list with more 
> knowledge about ICC profiles would help me. The ICC specification 
> (ICC.1:2004-10) states:
> 
> "All tagged element data, including the last, shall be padded by no more 
> than three following pad bytes to reach a 4-byte boundary"
> 
>  and
> 
> "This implies that the length must be a multiple of four"
> 
> However, if one looks at GRAY.pf supplied with OpenJDK, it is only 554 
> bytes long, which is NOT a multiple of four. Dumping the contents of the 
> file and parsing by hand, I see that the last tagged element data in 
> this file is (all other data is properly padded):
> 
> 63 75 72 76 00 00 00 00 00 00 00 01 01 00
> 
> This is clearly not padded to a four-byte boundary. Am I 
> misunderstanding something or is this a known problem? [I have not 
> investigated the cause of this: it could simply be a bug in the profile 
> or it could be a more serious LCMS bug with padding the last tagged 
> element data.]
> 
> Keith