Encodes a PCX image. The _encode and the encode functions are identical
The options argument may be a mapping
containing zero or more encoding options:
normal options:
"raw":1
Do not RLE encode the image
"dpy":int
"xdpy":int
"ydpy":int
Image resolution (in pixels/inch, integer numbers)
"xoffset":int
"yoffset":int
Image offset (not used by most programs, but gimp uses it)