xbmtopbm

Convert an XBM image to a PPM image

$ xbmtopbm [path/to/input_file.xbm] > [path/to/output_file.pbm]

xbmtopbm [input_file.xbm]

The xbmtopbm utility is an essential component of the Netpbm image manipulation toolkit. Its primary function is to convert image files from the X11 bitmap (XBM) format, commonly used within the X Window System for representing cursors, glyphs, and small monochrome icons, into the portable bitmap (PBM) format.

PBM is one of the foundational formats of the Netpbm suite, designed for simplicity and portability, representing black and white (monochrome) images with one bit per pixel. By transforming XBM files into PBM, xbmtopbm enables these bitmaps to be seamlessly integrated into a broader image processing workflow. This allows users to leverage the extensive array of other Netpbm tools for further manipulation, conversion to other formats, or analysis.

The command operates as a filter: it typically reads the XBM data from standard input if no file is specified, or from a provided input file, and writes the resulting PBM data to standard output, making it highly suitable for use in Unix-like shell pipelines.

Input files must strictly adhere to the XBM file format specification; malformed or non-standard XBM files may cause errors or unexpected output.

xbmtopbm produces monochrome PBM output exclusively, as XBM is inherently a 1-bit per pixel format. Any implied color information from the XBM source (which is rare for XBM) would be lost.

To convert an XBM file named image.xbm to a PBM file named image.pbm:

xbmtopbm image.xbm > image.pbm

To use xbmtopbm in a pipeline, reading from standard input and writing to standard output:

cat image.xbm | xbmtopbm > image.pbm

xbmtopbm is an integral part of the Netpbm suite of graphics tools, which originated from the PBMplus package developed by Jef Poskanzer in the late 1980s. The Netpbm project's core philosophy emphasizes creating small, modular utilities that perform a single task well and can be chained together using standard Unix pipes.

xbmtopbm perfectly embodies this design, providing a straightforward and reliable conversion function. Its inclusion in the suite ensures interoperability between the specific XBM format used by the X Window System and the versatile Netpbm ecosystem, thereby extending the utility and processing capabilities of XBM files within a wider range of image manipulation tasks.

pbmtoxbm(1), xbm(5), pbm(5), netpbm(1)