Convert CALS to PNM

The CALS (Continuous Acquisition and Life-cycle Support) Type 1 Image file format, developed by the United States Department of Defense in the mid-1980s, is a standard for storing raster (bit-mapped) image data, typically black-and-white. It ensures efficient data interchange and retention of orientation metadata. The format supports both uncompressed and compressed (using CCITT Group 4 compression) images. This standard was part of the broader CALS initiative aimed at improving electronic publishing and data management within the federal government.

The PNM (Portable Anymap) file extension, developed by Jef Poskanzer in the 1980s, stands for Portable Any Map. It is an uncompressed raster graphics format designed for portable image storage and exchange, encompassing three sub-formats: PBM (Portable Bitmap), PGM (Portable Graymap), and PPM (Portable Pixmap). PNM files store image data in plain text or binary format, ensuring easy usage across different platforms and applications. This format is widely supported by various image editing software and is valued for its simplicity and lossless compression.