ilbmtoppm

Convert an ILBM file to a PPM image

$ ilbmtoppm [path/to/file.ilbm] > [path/to/file.ppm]

$ ilbmtoppm [[-t|-transparent]] [color] [path/to/file.ilbm] > [path/to/file.ppm]

$ ilbmtoppm [[-ig|-ignore]] [chunkID] [path/to/file.ilbm] > [path/to/file.ppm]

$ ilbmtoppm [[-m|-maskfile]] [path/to/maskfile.pbm] [path/to/file.ilbm] > [path/to/file.ppm]

ilbmtoppm [options] [ilbmfile]

-gamma value
    Adjusts the output gamma to the specified value.
This is particularly useful for correcting the brightness and contrast
perception of images originating from different display systems,
such as the Amiga's native gamma.

-truecolor
    Forces the output to be a TrueColor (24-bit) PPM image,
even if the input ILBM uses a paletted color depth.
This ensures maximum color fidelity in the output, avoiding palette quantization.

-nointerleave
    Prevents the command from interleaving the output data.
By default, ilbmtoppm might interleave output planes for certain
ILBM types; this option disables that behavior.

-verbose
    Enables verbose output, causing the command to print
informational messages and status updates to standard error
during processing. Useful for debugging or understanding
the conversion process.

-transparent transparentcolor
    Specifies a transparentcolor for the output PPM.
This option is only applicable to 24-bit TrueColor images.
The transparentcolor must be specified as an ILBM color map index
(0-255) for paletted images, or as a hexadecimal RGB value
(e.g., #RRGGBB) for TrueColor images.

-noheader
    (Deprecated)
Prevents the command from writing the PPM/PGM header.
This option is deprecated and its use is discouraged as it produces
non-standard Netpbm output, which is generally not compatible
with other Netpbm tools.

-norunlen
    Prevents the command from interpreting run-length encoded (RLE) data
within the ILBM file. This is rarely used and typically
only for debugging or specific compatibility needs.

ilbmtoppm is a powerful command-line utility within the Netpbm suite, designed for converting image files from the IFF ILBM (Interchange File Format
Image Layer and BitMap) format to the Netpbm family of image formats, specifically PPM (Portable Pixmap) or PGM (Portable Graymap).
The IFF ILBM format was notably used on Amiga computers.

This tool reads an ILBM image file, processing its bitmap data, color palettes, and other associated information to reconstruct the image
in a standard Netpbm format. PPM is used for true-color or paletted images, while PGM is used if the input ILBM is a grayscale image.
The resulting PPM or PGM data is typically written to standard output, making it easy to pipe to other Netpbm tools for further
manipulation, such as scaling, format conversion, or combining with other images.

ilbmtoppm handles various ILBM features, including different bitplane depths and compression types. It's an essential
bridge for users working with legacy Amiga graphics or those who need to integrate ILBM files into modern image
processing workflows that rely on Netpbm's versatile toolkit.

ilbmtoppm generally produces PPM or PGM output to standard output.
This means that to save the output to a file, redirection
(e.g., `ilbmtoppm image.ilbm > image.ppm`) is necessary.
The -noheader option is deprecated and should be avoided
as it creates malformed Netpbm files.
Handling of all possible ILBM sub-formats or non-standard
ILBM files might not be exhaustive, and some exotic ILBM
variations could cause issues or produce incorrect output.
The -transparent option expects a specific color representation,
either an ILBM palette index or a hexadecimal RGB value.

If no ilbmfile is specified, ilbmtoppm reads the ILBM
image data from standard input. This allows for piping
output from other commands directly into ilbmtoppm.

The output format (PPM or PGM) is automatically
determined by ilbmtoppm based on the characteristics
of the input ILBM file. If the ILBM contains color
information or is a true-color image, PPM is produced.
If it's a grayscale image, PGM is produced.

ilbmtoppm is a component of the Netpbm project,
a venerable and widely used toolkit for graphics manipulation
on Unix-like operating systems.
Netpbm itself evolved from Pbmplus, a package created
by Jef Poskanzer in the late 1980s.
The inclusion of ilbmtoppm reflects the importance of
converting images from popular legacy formats like IFF ILBM
(prevalent on Amiga systems) into a universal, easily
processable format like Netpbm's PPM/PGM.
Its development is part of Netpbm's ongoing effort to provide
a comprehensive set of tools for various image formats and
operations, maintaining compatibility with historical data
while enabling modern image processing pipelines.

ppm(5), pgm(5), pbmtoppm(1), ppmtoilbm(1), netpbm(1), anytopnm(1)