2006.09.22 01:07 "[Tiff] Status of ISO JBIG and CIELAB JPEG support", by A Wandering LibTIFF User

2006.09.25 17:08 "Re: [Tiff] Status of ISO JBIG and CIELAB JPEG support", by Joris Van Damme

Joris wrote:

<http://bugzilla.remotesensing.org/show_bug.cgi?id=736>

>

> It is dangerous trying to build support for something based on > bugzilla attachment, as many a bugzilla attachment is totally bazurk.

> Here's a [lengthy analysis].

In addition, the image is somewhat dangerous because it's not CIE Lab at all.

When viewing this image with the proprietary AWare Systems TIFF codec, it seems totally bazurk. Colors are completely out of whak. Remembering how this image was constructed, I tried changing the Photometric. Sure enough, the image makes perfect sense when colors are interpreted as ITU Lab instead of CIE Lab.

This image is not CIE Lab at all, even if the Photometric incorrectly says so. It can be used as a testimage, but getting correct colors would indicate incorrect handling, and the other way around, so beware.

I've merged this final note with the original analysis, and added it to the the bugzilla entry so as to avoid people using this image as a testimage without being aware of the quircks in the future.

Best regards,

Joris Van Damme
info@awaresystems.be
http://www.awaresystems.be/
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