PhotoChrome

File Format
Name	PhotoChrome
Ontology	Electronic File Formats Graphics Atari graphics formats PhotoChrome
Extension(s)	.pcs

PhotoChrome (or PhotoChrome Screen) is a raster image file format used on Atari ST computers. It is associated with the PhotoChrome image viewer and converter software by Douglas Little. Later versions of PhotoChrome, from version 5, can only encode images and doesn't include a viewer.

Format

Files have a 6-byte fixed header. It is followed by several segments containing the palette and pixel data, which are RLE-compressed.

The image dimensions are always 320×200 pixels, but the first row is typically not used (apparently due to hardware limitations), making them effectively 320×199.

Some PhotoChrome files contain two separate images. On an actual Atari ST computer, the viewer would be expected to average them together using temporal dithering, to simulate more colors than the computer could actually display.

Identification

Files start with bytes 01 40 00 c8 (representing the width and height).

Software

• Konvertor
• RECOIL
• PhotoChrome

Sample files

• http://cd.textfiles.com/suzybatari2/pcs/
• http://samples.libav.org/image-samples/atarist/photochrome/
• RECOIL sample files → PAROT2.PCS, TIGER.PCS
• PhotoChrome → BAY2.PCS, BETTY.PCS
• dexvert samples — image/photoChrome

Links

• ST Picture Formats
• MultimediaWiki article

External Links

• PhotoChrome homepage