View CALS Files

CALS refers to a raster file format and entails that the files are black and white images that can be uncompressed or compressed, the latter having the specific CCITT group 4 encoding algorithm. The file format is available as Type I and Type II, the first one being a very simplistic file that contains a plain monochrome image with a raster header record.

Type II CALS images are more complex as they incorporate several monochrome images. Moreover, the data is interpreted as a collection of pel tiles and each is encoded separately using the aforementioned encoding.

As a fun fact, the format was developed in the 1980s for the purpose of standardizing graphics data interchange for electronic publishing for the federal government. Nevertheless, they soon came into wide use in the commercial computer industry, including but not limited to the aerospace industry as well as CAD and CAM applications.

Since this raster format is commonly used with advanced graphic viewers and editors, then it means that you are unable to access them unless you choose a specialized visual tool. It is worth mentioning that the following utilities do not solely enable you to access files featuring this extension, but also edit them using a vast array of advanced tools and features.