ilbmtoppm

Section: User Commands (1)
Updated: 25 October 1994
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NAME

ilbmtoppm - convert an IFF-ILBM, IFF-RGBN or IFF-RGB8 file into a portable pixmap

SYNOPSIS

ilbmtoppm [-verbose] [-ignore chunkID] [-isham|-isehb|-isdeep|-isnotham|-isnotehb-isnotdeep] [-cmaponly] [-adjustcolors] [-transparent color] [-maskfile filename] [ILBMfile]

DESCRIPTION

Reads an IFF-ILBM, IFF-RGBN or IFF-RGB8 file as input. Produces a portable pixmap as output. Supported ILBM types are:

Normal ILBMs: 1-8 planes with or without colormap, or 9-16 planes with colormap. If no colormap is present, interprets the pixel values as intensity (grayscale) values. Amiga display modes Extra_Halfbrite (EHB) and Hold-and-modify (HAM) are supported, and the multiplatte formats Palette Change (PCHG chunk), Dynamic HAM/Hires (CTBL chunk) and Sliced HAM (SHAM chunk). HAM images are limited to 3-10 planes.
Deep ILBMs: 9, 12 or 15 planes without colormap, or 18-48 planes (the number of planes must be divisible by 3). Most deep ILBMs have 24 planes (for 8-bit RGB values).
Colormap files: BMHD + CMAP chunk only, 0 planes.
Chunks used:: BMHD, CMAP, CMYK, CLUT, CAMG, PCHG, CTBL, SHAM, BODY
Chunks ignored:: GRAB, DEST, SPRT, CRNG, CCRT, DYCP, DPPV, DRNG, EPSF, JUNK, CNAM, PRVW
Other chunks (ignored but displayed in verbose mode):: ANNO, AUTH, (c), DPI, FVER, NAME, TEXT
Unknown chunks are skipped.

OPTIONS

Options marked with (*) can be prefixed with a "no", e.g. '-noverbose'. All options can be abbreviated to their shortest unique prefix.

-verbose (*): Give some information about the input file.
-ignore chunkID: Skip a chunk. chunkID is the 4-letter IFF chunk identifier of the chunk to be skipped. This option can appear more than once on the command line.
-isham | -isehb: Treat the input file as a HAM or EHB picture, even if these flags or not set in the CAMG chunk (or if there is no CAMG chunk). This option has no effect with RGBN and RGB8 pictures.
-isnotham | -isnotehb: Do not treat the input file as a HAM or EHB picture, even if these flags are set in the CAMG chunk. This option has no effect with RGBN and RGB8 pictures.
-isdeep: Treat an input file with less than 16 planes as a deep ILBM, even if it provides a colormap. The number of planes in the input file must be divisible by 3. This option has no effect with RGBN and RGB8 pictures.
-isnotdeep: Do not treat an input file as a deep ILBM, even if it has more than 8 planes and/or no colormap. This option has no effect with RGBN and RGB8 pictures.
-adjustcolors (*): Scale a 4-bit colormap or shifted 4-bit colormap to 8 bits. If this option is not used and believes that the colormap consists of 4-bit values or shifted 4-bit values, it prints a warning. This option has no effect with RGBN and RGB8 pictures.
-cmaponly: Extract only the colormap from the input file. The resulting PPM file will be in P3 ASCII format. This option results in an error if used with a RGBN or RGB8 file.
-transparent color: Write transparent pixels in color instead of their colormap entry. The color is specified as in ppmmake(1).
-maskfile filename: Generate a mask file from a mask plane or transparent color entry (ILBM), or genlock bits (RGBN/RGB8) and write it to filename. This is a normal PBM image, the same size as the PPM output file. A pixel value of PBM_WHITE in the mask file means the corresponding in the output file is considered to be transparent, PBM_BLACK indicates an opaque pixel (think of the output file casting a shadow on a white screen).

BUGS

Lasso masks are not supported. CLUT and CMYK chunk code is untested.

REFERENCES

Amiga ROM Kernel Reference Manual - Devices (3rd Ed.), Addison Wesley, ISBN 0-201-56775-X, Appendix A: Interchange File Format

AUTHORS

This document was created by man2html, using the manual pages.
Time: 13:13:58 GMT, March 01, 2022