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- --------I-PCX-------------------------------
-
- The PCX files are created by the programs of the ZSoft Paintbrush family
- and the FRIEZE package by the same manufacturer. A PCX file contains
- only one image, the data for this image and possibly palette information
- for this image. The encoding scheme used for PCX encoding is a simple
- RLE mechanism, see ALGRTHMS.txt for further information. A PCX image is
- stored from the upper scan line to the lower scan line.
-
- The size of a decoded scan line is always an even number, thus one
- additional byte should always be allocated for the decoding buffer.
-
- The header has a fixed size of 128 bytes and looks like this :
- OFFSET Count TYPE Description
- 0000h 1 byte Manufacturer.
- 10=ZSoft
- 0001h 1 byte Version information
- 0=PC Paintbrush v2.5
- 2=PC Paintbrush v2.8 w palette information
- 3=PC Paintbrush v2.8 w/o palette information
- 4=PC Paintbrush/Windows
- 5=PC Paintbrush v3.0+
- 0002h 1 byte Encoding scheme, 1 = RLE, none other known
- 0003h 1 byte Bits per pixel
- 0004h 1 word left margin of image
- 0006h 1 word upper margin of image
- 0008h 1 word right margin of image
- 000Ah 1 word lower margin of image
- 000Ch 1 word Horizontal DPI resolution
- 000Eh 1 word Vertical DPI resolution
- 0010h 48 byte Color palette setting for 16-color images
- 16 RGB triplets
- 0040h 1 byte reserved
- 0041h 1 byte Number of color planes
- ="NCP"
- 0042h 1 word Number of bytes per scanline (always even,
- use instead of right margin-left margin).
- ="NBS"
- 0044h 1 word Palette information
- 1=color/bw palette
- 2=grayscale image
- 0046h 1 word Horizontal screen size
- 0048h 1 word Vertical screen size
- 004Ah 54 byte reserved, set to 0
-
- The space needed to decode a single scan line is "NCP"*"NBS" bytes, the
- last byte may be a junk byte which is not displayed.
-
- After the image data, if the version number is 5 (or greater?) there
- possibly is a VGA color palette. The color ranges from 0 to 255, 0 is
- zero intensity, 255 is full intensity. The palette has the following
- format :
-
- OFFSET Count TYPE Description
- 0000h 1 byte VGA palette ID (=0Ch)
- 0001h 768 byte RGB triplets with palette information
-
- EXTENSION:PCX
- OCCURENCES:PC
- PROGRAMS:PC Paintbrush
- SEE ALSO:
-