I first compiled ImageMagick 10 or 12 years ago, long before Red Hat or Linux were around. At that time, I don't believe PCL was supported, but it is significant piece of work.
For format conversions in the Windows environment, the Hijaak Express package is inexpensive and can convert a long list of image formats to whatever, including PCL.
While it only supports BMP, PCX, and JPG, my MKPCL program provides much better PCL support than the others, and it is available for SCO, DOS, Linux, and freeBSD. It does more than just convert the format. Of particular interest is the option to specify the PCL output as a macro, PCL compression that can reduce filesize immensely particularly on bi-level files, and the ability to embed the printing location on the sheet in the file. A bunch of other options are there as well.
As with many computer tasks, there are a number of approaches to accomplish your ends. Over the years, and I have been doing this for a long time, I have found that it is almost always best to set up PCL images as macros. It is simply easier to work with them and considerably more flexible within your application when the image is a macro.
Certainly, you can add the macro code by hand to any PCL file that lacks it.
Jim Asman
jlasman@telus.net