2006.10.16 20:34 "[Tiff] Tag 346", by Ross Presser

2006.10.16 22:18 "Re: [Tiff] Tag 346", by Toby Thain

On 16-Oct-06, at 5:47 PM, Ross Presser wrote:

Is there any extant software anywhere that implements this,

>> either for

writing or reading? (I have some hints that Pagemaker supported

>> it at

some point.)

Also, are there any sample images anywhere?

To the best of my knowledge, that's a 'no' on both questions. I've never seen any file come my way that uses the Indexed tag.

Thanks for that information. It certainly makes sense then; the tag was proposed without having been fully thought out, so it never got used.

The reason I asked is slightly off topic for TIFF, in fact. As you probably know, the PDF spec does support Indexed images in any colorspace defined in the PDF. In fact, the default profile for Adobe Distiller will automatically convert *all* images in the source to indexed images as long as the total color count is less than 256. This can yield some terrific compression: the files in my workflow each contain a single 8636x9144 pixel bitmap that uses only three colors -- black, white, and 100% magenta; the file sizes range from under a megabyte to about three megabytes. It's perfect for this application.

Did you try using LZW or ZIP compression on the 32-bit CMYK TIFF?