I was trying to explain this to someone the other day and I realized that I did not really know what I was talking about. Can some one explain it and also (just casually) compare the differences between a full feature RIP like StudioPrint vs. a limited feature RIP like ImagePrint vs. a layout program like QImage?
Thanks
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That you didn't know what you were talking about is more the result of the many flavors RIPs have these days than a lack of knowledge I think. In its simplest form a Raster Image Processor could apply as well to just an OEM printer driver today so the field is wide.
In the original version a RIP was used on image setters to produce (halftone) films on image setters. The films again were used to make offset printing plates or similar image carriers in other printing processes. At that time the RIP was a very proprietary solution and integrated in the total hardware system of the image setters.
Drivers for desktop printers at that time had very limited in functions, big printers didn't exist. The RIP hardware approach was followed in the first RIP kind of laserprinters among them the first Postscript laser printers that had a PS RIP engine inside. With the wider use of desktop computers and the introduction of software like Freedom of Press, Ghostscript etc, that translated documents in PS to the driver languages like PCL, more market pressure on propriatery hardware solutions grew. At the same time use of RIPs outside the image setter's world really started to grow for printers, plotters etc and with that the variety also increased. Conventional halftone screening got new stochastic screening etc next to it, the Postscript language itself was further developed. The development of all that had been along the path of text>document>illustrations added, while image setters allowed reproduction of photography there were no laser or inkjet printers with an acceptable photo quality. That change came with the introduction of the Iris inkjet printers.
The variety in RIPs we know now is the result of the different needs now and the history of the developments mentioned above. There still are software and hardware solutions but the first have the advantage now. They all do the basic Raster Image Processing on bitmaps, some will do the rasterisation of vectors and vector based fonts (Postscript based mainly), some have to rely on other applications to do the last (Acrobat, Photoshop, some third party clones). There are dedicated software RIPs now that are designed for photography + image reproduction only and deliberately have no PS etc interpretation, often driving just one type of printer per license. ImagePrint is one example. There are software RIPs that have almost all the functions a RIP can have considering the history of functions and the needs today, RIPs that still can drive image setters, laser printers, wide electrostatic (laser) printers, the latest wide inkjets and RGB devices like digital photoprinters on analoge material. With Postscript and HPGL interpretion, with color management in CMYK and RGB style, with economic nesting of the documents/images on the paper/film width. Often optional extensions cover an even wider field of functions like profile creation, textile printing, cutting plotter drivers, UV curing inkjet flatbed printers etc. Licenses cover 30 or 40 printer drivers and say 4 printers can be driven from one RIP. The Wasatch SoftRip is an example. In that case the Postscript interpretation is based on Jaws (name must have been changed meanwhile) one of the more successfull third party PS interpreters.
There's another distinction between RIPs and that is related to the way they handle their color management. In a RIP with CMYK style printer CM system there are more elements of the paper/ink settings incorporated in the profile creation. Inklimit, black generation, LC>C etc partitioning choice, CMY balance and even more. In an RGB style printer profiling system that part is a black box and the profiling is laid on top in RGB style like one would use for an RGB device: monitors, scanners or RGB photoprinters. OEM drivers are in that category. ImagePrint is similar but one can get a new media profile (settings) + RGB profile from the company at request. After that one can make custom RGB profiles based on that new media profile like one can make a custom profile on a normal OEM driver media profile. Your example of Qimage + the OEM driver is very close to what Imageprint can offer, Qimage's nesting of images on the sheet or roll is a normal RIP function, its extrapolation routines are second to none even compared to RIPs, the RGB style color management is at Photoshop level and depending on the media profiles number that are available for your printer of choice, the lack of custom media profiles (optional with ImagePrint) may be no problem. The quality of dithering, weaving, in the actual print is the responsibility of the printer driver manufacturer and they know what the competition delivers. So though it is a combination of applications it still gets close to today's RIP category in functions and quality. Add Acrobat in the chain and PS interpretation is available too (at Adobe level!). The Wasatch SoftRip and some other RIPs introduced RGB style profiling also for inkjet profiling next to their CMYK profiling some years ago, one of the reasons was the introduction of some N-color printers that use more than the CMY hue inks. In some cases profiling was considered easier that way. The main difference is that the media settings etc are still transparent even with RGB style profiling.
I'm sure I didn't cover all aspects of RIPs and I doubt the story above makes it easier to explain to someone else what a RIP is. It is a moving target in the first place that changes shape on the move too.
Ernst Dinkla
try: [a href=\"http://groups.yahoo.com/group/Wide_Inkjet_Printers/]http://groups.yahoo.com/group/Wide_Inkjet_Printers/[/url]
