- Extension
- .cal
- .g4
- Format
- Binary
- Binary
- Category
- Raster Image
- Fax
- Developer
- U.S. Department of Defense
- Computer Fax Systems (CFS)
- 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.
- Group 4 (G4) used for black and white lossless compression to maintain high-quality images, commonly used in TIFF format compression by fax machines. A picture is seen as black dots and lines on a blank page; the fewer the dots and lines are, the lesser the file size.
- MIME Type
- image/cals
- image/g4fax
