Path: utzoo!attcan!uunet!cs.utexas.edu!sun-barr!apple!well!shiva From: shiva@well.sf.ca.us (Kenneth Porter) Newsgroups: comp.lang.postscript Subject: Re: Help! Summary: Use of settransfer and image procs Message-ID: <20829@well.sf.ca.us> Date: 28 Sep 90 18:43:41 GMT References: <265@pb2esac.UUCP> Lines: 23 To my knowledge, the image operator has its own idea of gray scale and ignores setgray values. If you just need 50% gray, add a second bitplane to the image and make the high-order bitplane all zeroes. You can synthesize this effect by creating an appropriate procedure that adds a zero after every bit, and pass this to image. The ability to pass a procedure to image to gather pixel values is quite powerful. You can get other grays by replacing each bit with an n-bit value representing a gray between 0 and 2^n-1. As Jamie Zawinski points out, settransfer can also be used, but you should modify his example to concatenate the new transfer proc with the result of currenttransfer, so that the result can be combined with previous transfer ops (the most important being any builtin engine compensation). Hope this helps. Ken (shiva@well.sf.ca.us)