2008.08.08 05:15 "[Tiff] Writing custom fields with big counts.", by Tom Harris

2008.08.11 02:19 "Re: [Tiff] Writing custom fields with big counts.", by Tom Harris

Thanks for the replies.

I know that TIFF is able to represent any possible combination of raster image data. This is so cool considering that the format is over 20 years old.

However, most desktop imaging applications (think something like Microsoft Picture Viewer) will choke on any multi-image TIFF that is not plain vanilla TIFF. By `vanilla' I mean the simplest legal set of tags for a 3 plane 8 bits per sample, and it is fairly limited as to what compression it can use. Adding extra planes or extra images will cause the app to not load the image.

My customers are biologists and medical specialists, who just want to acquire some data, put it on a CD, take it home and look at the images with the same apps that they use for their holiday snaps. This is why I want to embed my source data in this strange way. I do not care that it uses a custom tag, as if the customer want to access the source data, then they have to use my custom app.

To reply to Andy's ideas:

  1. Put multiple images in a single file. Your main first image would be the RGB data that most applications will view and your second image would be your scientific data.

Will cause desktop imaging apps to choke. Besides I need multi-image TIFFs.

  1. Make your image an RGB image with extra samples (which are your scientific data), where these are marked as "unspecified". See page 31 for details on this.

Good idea, but the source data is 16 bit at present, and may change to 32 bit. Libtiff does not allow images with planes of different bitdepths. I suspect that common desktop apps will choke on this as well, as they are so badly coded.

  1. Alternatively and even simpler, just create two TIFF files with similar names but one being slightly different to indicates it's the scientific data.

No good I'm afraid, this sort of thing is beyond our customers. I know these people are professionals that we routinely trust with our lives, but getting them to copy two sets of files is impossible.

Thanks so much for the reply.

Tom Harris