Convert cals to pnm

What is the difference between .cals and .pnm?

Description: The CALS Raster Graphic File, having the extension .cals, is a type of image file format primarily used for the storage and exchange of digital images, especially in the context of technical and engineering documents. Developed in the mid-1980s by the United States Department of Defense, the CALS format was part of an initiative to standardize electronic document management and interchange, particularly for military and government applications.; The PNM (Portable Any Map Image) file format is a subset of the broader Netpbm format, designed for storing various types of digital images. It acts as an umbrella term for three specific types of grayscale, color, and black-and-white images, represented by PBM (Portable Bitmap), PGM (Portable Graymap), and PPM (Portable Pixmap) formats respectively. PNM files are known for their simplicity and ease of conversion to other image formats.