Convert HPGL to PHM

The HPGL file extension, short for Hewlett-Packard Graphics Language, is a file format and printer control language developed by Hewlett-Packard in 1977 for use with their plotter printers, starting with the HP-9872. HPGL files contain commands that instruct plotters to draw images using lines rather than dots, making them essential in CAD applications and technical drawings. The language uses a series of two-letter codes followed by parameters to control the plotter's actions, such as moving the pen or drawing shapes.

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.