Dexxa TIFF

This article describes an unusual variant of TIFF that is the native color image format of RainBow Paint, PaintShow, PaintShow Plus, and possibly Paint It!. These are names of different versions of a paint program for DOS by Dexxa International and/or Logitech. The software was sometimes packaged with Logitech/Dexxa mice.

The software includes TIF2PCX.EXE, a utility to convert the format to PCX.

Disambiguation
RainBow Paint is not to be confused with Rainbow Painter.

Format details
The color mode can be selected by setting an environment variable prior to running the software. For example:
 * " " - 16-color
 * " " - 4-color
 * " " - black and white

16-color images
The 16-color format is not compatible with standard TIFF (at least not TIFF revision 4 or higher).

The image is labeled as RGB color, but in fact is palette color. The default 16-color PC/CGA palette is used, and is not stored in the file. (Note that some versions of the software predate TIFF 5.0, which introduced support for palette color.)

The image is labeled as planar, 4 samples/pixel, and usually 1 bit/sample, though 4 bits/sample is also possible (e.g. TRAIN1.TIF included with PaintShow 1.1).

4-color images
4-color images appear to use a reasonably standard grayscale TIFF format, interpreted in a nonstandard way. This might depend on the type of compression selected.

Black and white images
Bi-level black and white images use a standard TIFF format.

Software

 * PaintShow 1.1 by Logitech
 * PaintShow 1.x by Logitech (at WinWorld)
 * PaintShow Plus 2.0 by Logitech (at Vetusware)
 * PaintShow Plus 2.x by Logitech (at WinWorld)
 * RainBow Paint 2.2 by Dexxa
 * - Supports 16-color images

Sample files

 * Some example files are included with PaintShow 1.1, and PaintShow Plus 2.0-2.1.

Links

 * A blog post about Paint It! and RainBow Paint (in Italian)