- Extension
- .cal
- .pnm
- Format
- Binary
- Binary
- Category
- Raster Image
- Raster Image
- Developer
- U.S. Department of Defense
- Jef Poskanzer
- Description
- The CALS raster file format, commonly known by the extension ".cal" or ".cals," is a bitmap file format designed primarily for the storage and interchange of digital images, especially in the field of computer-aided design (CAD) and engineering. Developed by the United States Department of Defense, it was intended to standardize the exchange of graphics data for electronic publishing of technical manuals. This format supports monochrome (1-bit) images and is distinguished by its efficient compression methods for reducing file sizes, facilitating easier storage and transmission. Despite its specific initial use case, the CALS raster format has found application in various industries for the archiving and sharing of high-resolution, scanned documents.
- 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.
- MIME Type
- image/cals
- application/x-portable-anymap