Convert PHM to PAM

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.

The PAM (Portable Arbitrary Map) file extension is a versatile bitmap format used primarily in UNIX-based systems. It extends the Portable Any Map (PNM) format, supporting 2-dimensional image data storage in a binary format with an ASCII header. Introduced to enhance flexibility and interoperability in image processing, PAM files are utilized for various graphical applications, offering a standardized method for handling diverse image types. This format's history traces back to the need for a more adaptable and comprehensive bitmap solution within the PNM family.