Better indexing on bitsavers

[Jules Richardson]

On Fri, 2005-05-20 at 10:25 -0500, John Foust wrote:
> At 10:01 AM 5/20/2005, Jules Richardson wrote:
> >Only about 20% of tools I've come across over the years actually
> >try and handle TIFFs properly
> 
> With tagged formats, the problem in my mind has always been
> a lack of mechanism for an app to decide what to do with 
> unknown tags while processing a file.  Do you throw out the
> tags or keep them?  

Well I suppose you preserve tags even if you don't understand them when
copying etc.

When decoding, you just skip any that you don't understand and in theory
your decoder either finds no image it can understand and breaks, or it
works.

Are there any vendor-unique TIFF tags out there that are indirectly
related to the image decoding process? I don't remember stumbling across
vendor-unique tags that say something like "apply xyz filter after
decoding and before displaying" or anything like that, so a decoder
should either be able to display the correct image or barf, but not
something inbetween. I could be wrong there though...

ISTR that the baseline TIFF tags that any decoder should understand
support quite a lot of useful fields (including metadata-like stuff,
like description, author, timestamp, software package etc.)

I tend to find that decoders are pretty good at handling the various
tags, they just often seem to be spectacularly crap at processing TIFF
files with multiple images in them - often because image tools are often
written with a 1:1 mapping between file and image in mind I suppose.

cheers

Jules