2013.10.28 07:43 "[Tiff] Does TIFF support 15-bit (RGB555 or 5551) images?", by Nikos Chantziaras

2013.10.28 13:50 "Re: [Tiff] Does TIFF support 15-bit (RGB555 or 5551) images?", by Bob Friesenhahn

Hello.

I've been trying a lot of experiments, but can't seem to be able to create a TIFF image file with 15-bit or 16-bit pixels. By that I mean formats like 5-5-5, 5-5-5-1 or 5-6-6. The parameters I'm trying are:

   SAMPLESPERPIXEL: 3 (and 4, hoping for 5-5-5-1)
   BITSPERSAMPLE: 5
   PHOTOMETRIC: RGB
   PLANARCONFIG: CONTIG

It just doesn't work. The created files seem to have a bit depth of 4 per channel (as reported by ImageMagick) and they display either garbled or in grayscale, depending on the viewer.

Is there a way to create such files with LibTIFF?

GraphicsMagick is able to produce and read the 5-5-5 format using libtiff. It can't do the the others since libtiff requires that all channels have the same depth. Note that TIFF stores the samples as tightly packed data so a 15 bit result will not align the samples to 16-bit words.

There are hardly any TIFF readers in the world which can read TIFF with unusual sample depths.

Microsoft's BMP format provides substantial support for sample depths which result in 16-bit pixels.

Bob
--
Bob Friesenhahn
bfriesen@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer, http://www.GraphicsMagick.org/