2004.10.01 09:59 "[Tiff] quad-tile", by Joris Van Damme

2004.10.01 13:57 "Re: [Tiff] quad-tile", by Frank Warmerdam

I believe quad-tile.tif is a testimage that I got from the 'official' tiff testimage package. I'm having a hard time making sense of it.

Scary! I am surprised it works in libtiff.

Sorry I don't have any info on how libtiff does it. I would have to do alot of deep digging to try and understand it I suspect.

I'll do that digging, and report back.

Meanwhile, it might be a good idea to remove quad-tile from the testimage suite, if it is still there. I assume anyone can build a proper tiled version, if needed... except for me, right now, state my code is in. If it's not replaced by the time I can restore my code, I will build a suitable replacement. In any case, I don't think it is sensible to leave such an image in a semi-official testimage suite.


The libtiffpic suite (thats where you got this, right?) includes a variety of "problem" TIFF files that are non-standard as well as various standards compliant files. While I don't recall all the history, I assume they exist so we have samples of the weird variants to help us maintain various hacks required to make them work.

So, I think the better solution might be to segregate our suite of test images into files considered to be standard and valid, and those that are invalid but that we want to work with anyways for purposes of interoperability.

I have been leaving the sample image management up to Andrey though, so perhaps he will have further thoughts. I do believe he is planning to augment the set of test images as he works on a libtiff test suite.

Best regards,

I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam@pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | Geospatial Programmer for Rent