Convert cals to png48

What is the difference between .cals and .png48?

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.; A PNG file is an image file stored in the Portable Network Graphic (PNG) format. It contains a bitmap of indexed colors and uses lossless compression, similar to a .GIF file but without copyright limitations. PNG files are commonly used to store graphics for web images.