Use this command to read frames in PFM format. PFM format is used for
HDR Shop plug-ins and is also supported by some recent versions of
NetPBM package (pamtopfm and pfmtopam commands). The frames are
converted to pfs stream and send to the Standard Output. This command
can handle both color and gray-scale images.
Details on the format of the pattern file names, which are used for
reading multiple frames, can be found in the manual page of pfsinppm.
To automatically recognize a file format from the extension, use
pfsin command instead.