Convert CALS to PHM

The CALS (Continuous Acquisition and Life-cycle Support) Type 1 Image file format, developed by the United States Department of Defense in the mid-1980s, is a standard for storing raster (bit-mapped) image data, typically black-and-white. It ensures efficient data interchange and retention of orientation metadata. The format supports both uncompressed and compressed (using CCITT Group 4 compression) images. This standard was part of the broader CALS initiative aimed at improving electronic publishing and data management within the federal government.

The PHM file extension stands for Portable Float-map Image (16-bit half), a format used for storing High Dynamic Range (HDR) images with 16-bit half-precision floating-point values. This format is particularly useful in applications requiring precise color representation and extensive dynamic range, such as computer graphics, image processing, and scientific visualization. Originating from the Portable FloatMap (PFM) format, PHM was developed to provide a more efficient storage solution by utilizing half-precision floats, thereby reducing file size while maintaining significant detail and accuracy.