PostScript 3: A RIPing Good Time
by John Bryan
Adobe's been noodling around with the bits and bytes that make up PostScript, and the good news is they've improved it. The bad news: You have to upgrade. More good news: You may want to.
"With a graphic that has a lot of blends or an ad with a lot of clip-art pictures of cars, you could process that page in half the time," says Gary Cosimini, a former New York Times staffer now toiling for Adobe Systems Inc. as its new-product manager.
He's speaking of Adobe PostScript Level 3, a further refinement of the revolutionary computer language that changed the tools of the graphics trade from light tables, Rubylith overlays and Xacto knives to banks of Macintoshes glowing softly on artists' desktops.
How? By making it possible to draw a complex image on a computer screen, then allowing a printer of some kind to put it on film, paper, plates, or whatever. In geekspeak, this is called a "non-trivial" process. For the rest of us, it's flat-out magic. But you'll appreciate the tricks more by taking a peek under the hood of newspapers' imaging workhorse, the RIP.
RIP stands for "raster-image processor." It takes an image, whether a letter of the alphabet, a picture or a line drawing, and converts it to a stream of digital information using Adobe's PostScript language.
That data stream moves to an imager, which can be as simple as an Apple LaserWriter or as complex as an Autologic Information International 3850 imagesetter, where a laser beam is told, "make a lot of little dots in the shape of an A," or "make a halftone image of a car." But with complex Illustrator, Freehand or QuarkXPress jobs, the conversation is more like this:
Software: I want you to make a curved shape containing 386 separate, filled polygons that will look like a line, and over here, I need another polygon that will have 37 separate tints, blending together. And that's just one plate. After we're done with the cyan, we need to do it all over again for magenta, yellow and black.
RIP: Go to hell.
And with that, the RIP stops, hangs or occasionally struggles bravely through the job, producing only part of the image.
The first thing manufacturers did was throw more horsepower at the problem, with faster and faster computers. That helped some, but it was still too easy for a complex print job (and artists can't help but make complex print jobs) to "choke" the RIP.
So Adobe (and PostScript clone makers such as Harlequin) went back to the drawing board to make more efficient RIPs, combining brute force and increasingly clever programs to turn these hideous print jobs into beautiful output. Among the results:
- Adobe has changed the way PostScript constructs blends to require fewer steps. So after convincing your artists that they can simplify their drawings with no loss of quality, artwork will be less complex and therefore easier to image.
- New RIP software can learn how a non-Adobe product such as Freehand makes a certain shape, then memorize it and convert it to faster, more efficient PostScript 3 routines. Moreover, programmers can load specific bits of translation code into the RIP to handle specific, repeatable problems, such as a strange way of ending text lines. With the workaround already loaded, the job can be processed much faster. "Think of what that would mean for a stock page," says Cosimini.
- Adobe emphasized in-RIP separations, which were in earlier
PostScript versions but seldom used. Instead of downloading the file
to the RIP for each of the four plates, the RIP holds the image in
memory and extracts the color information in one pass.
"The benefit," says Cosimini, is that "color management will be possible for the first time." With in-RIP color separation, he adds, "what I see on the screen is what I see on the proof is what I see on the press. The circuit is complete."
- With the emergence of PostScript 3 on a friendly RIP near you, the lowly, oft-maligned (with reason) Portable Document Format, or PDF, may finally be ready for the Big Time.
"PDF, the document-viewing format?" you might ask. "So what?"
So plenty: PostScript 3 RIPs process PDF files in their native form. They don't have to be exported to EPS format to image on a page. This saves time, effort and the sanity of pre-press operators who have to untangle the occasional corrupt EPS file. What's more, color PDF files separate inside the RIP, where everything's under the same color control. That means easier and faster color processing, and that in turn is a huge help to the burgeoning PDF-based AdSend service from The Associated Press.
"In 1997, we moved over 1 million PDF files to 1,460 newspapers on behalf of 507 advertisers," says AdSend Director Jim Farrell. "We expect to move about a million and a half this year." With that volume, a step saved here and there translates into huge savings all around the industry.
And that's just the beginning. Quark Inc. is developing a plug-in that will allow QuarkXPress 4.0 to place PDF files on pages; other vendors also plan similar capabilities.
Can PDF get so muscular it can replace PostScript itself? It might--when PDF files become fully editable, the file format, with its imbedded fonts and compression, will not be far from being a page-description language in its own right.
And PDF's not so far from replacing open pre-press interface (OPI) systems as well. Who needs to put a low-resolution file on a page and replace it later when you can just crunch the huge graphics file into a reasonable PDF file, place it directly on the page and be done with it? Another production step, and the bucks that go with it, saved.
Where will it all end? The better question is: Where will it all start?
A few vendors, notably Agfa and PrePress Solutions Inc., now offer PostScript 3 RIPs. And many others are expected to roll out their versions, probably around NEXPO. Harlequin, Adobe's imaging archrival, has already advertised PostScript 3 compatibility.
Now the problem is getting the new RIPs out of showrooms and into composing rooms. "I'm not sure how many newspapers will jump on the Level 3 bandwagon," says Janet Loprano, AdSend's senior applications specialist. "While the world is going PostScript 3, the newspaper industry tends to move more conservatively."
John Bryan is on the Information Technology staff of the Los Angeles Times. E-mail: john.bryan@latimes.com.