Graphic Workshop self-displaying picture
(The "320x480" claim needs clarification. The samples we're linking to are 640x480 and 633x475, 4bpp.) |
(Compression info) |
||
| Line 12: | Line 12: | ||
The Windows 3.x format was introduced in Graphic Workshop for Windows 1.1h. Note that Graphic Workshop for Windows also supports the DOS format. | The Windows 3.x format was introduced in Graphic Workshop for Windows 1.1h. Note that Graphic Workshop for Windows also supports the DOS format. | ||
| + | |||
| + | == Format details == | ||
| + | |||
| + | === Compression scheme === | ||
| + | In DOS EXE format, the image data is compressed by default. It uses what appears to be simple byte-oriented [[Run-length encoding|RLE]] scheme. | ||
| + | |||
| + | To decompress: Read a byte (N), follow the instructions for the corresponding table row, repeat. | ||
| + | |||
| + | {| class="wikitable" | ||
| + | ! Code byte (N) !! Instructions | ||
| + | |- | ||
| + | |N < 0xc0 || Emit byte N literally. | ||
| + | |- | ||
| + | |N ≥ 0xc0 || Emit the next byte N−0xc0 times. | ||
| + | |} | ||
== Identification == | == Identification == | ||
Revision as of 13:53, 25 October 2024
Graphic Workshop self-displaying picture is a family of raster graphics formats associated with the Graphic Workshop lines of image processing software from Alchemy Mindworks.
It is in the form of a DOS or Windows 3.x EXE file that displays the image when executed. Quite possibly there are newer formats as well, but more research is needed.
The DOS format was introduced in Graphic Workshop 6.0.
The Windows 3.x format was introduced in Graphic Workshop for Windows 1.1h. Note that Graphic Workshop for Windows also supports the DOS format.
Contents |
Format details
Compression scheme
In DOS EXE format, the image data is compressed by default. It uses what appears to be simple byte-oriented RLE scheme.
To decompress: Read a byte (N), follow the instructions for the corresponding table row, repeat.
| Code byte (N) | Instructions |
|---|---|
| N < 0xc0 | Emit byte N literally. |
| N ≥ 0xc0 | Emit the next byte N−0xc0 times. |
Identification
Undetermined. For DOS EXE format, a software name like "GraphicWorkshop 7.0" or "GWS/Windows 1.1u" appears at offset 541.
Software
- Graphic Workshop (read/write)
In Windows versions of the format, the image may be stored as a standard BITMAP resource, so it can be read by any suitable resource viewer software.
Sample files
DOS EXE:
- BGI20.ZIP → most EXE files
- INFODSK3.ZIP → most EXE files
- HERBAGE.ZIP → *.EXE
- dmenu2.zip → DALOGO.EXE
- MTRCYCLE.ZIP → README.EXE
Windows 3.x EXE:
- GWSWN11U.ZIP → gwswn11u.exe → CLICKME*.EXE
