What is a Raster Image Processor (RIP)?

Ever wondered what a raster image processor or RIP does? And what does RIPping a file mean? Read on to learn more about the phases of a RIP, the engine at the heart of your Digital Front End (DFE).

The RIP converts text and image data from many file formats including PDF, TIFF™ or JPEG into a format that a printing device such as an inkjet printhead, toner marking engine or laser platesetter can understand. The process of RIPping a job requires several steps to be performed in order, regardless of the page description language (such as PDF) that it’s submitted in. Even image file formats such as TIFF, JPEG or PNG usually need to be RIPped, to convert them into the correct color space, at the right resolution and with the right halftone screening for the press.

Interpreting: The file to be RIPped is read and decoded into an internal database of graphical elements that must be placed on the output. Each may be an image, a character of text (including font, size, color etc), a fill or stroke etc. This database is referred to as a display list.

Compositing: The display list is pre-processed to apply any live transparency that may be in the job. This phase is only required for any graphics in formats that support live transparency, such as PDF; it’s not required for PostScript language jobs or for TIFF and JPEG images because those cannot include live transparency.

Rendering: The display list is processed to convert every graphical element into the appropriate pattern of pixels to form the output raster. The term ‘rendering’ is sometimes used specifically for this part of the overall processing, and sometimes to describe the whole of the RIPing process.

Output: The raster produced by the rendering process is sent to the marking engine in the output device, whether it’s exposing a plate, a drum for marking with toner, an inkjet head or any other technology.

Sometimes this step is completely decoupled from the RIP, perhaps because plate images are stored as TIFF files and then sent to a CTP platesetter later, or because a near-line or off-line RIP is used for a digital press. In other environments the output stage is tightly coupled with rendering, and the output raster is kept in memory instead of writing it to disk to increase speed.

RIPping often includes a number of additional processes; in the Harlequin RIP® for example:

  • In-RIP imposition is performed during interpretation
  • Color management (Harlequin ColorPro®) and calibration are applied during interpretation or compositing, depending on configuration and job content
  • Screening can be applied during rendering. Alternatively it can be done after the Harlequin RIP has delivered unscreened raster data; this is valuable if screening is being applied using Global Graphics’ ScreenPro™ and PrintFlat™ technologies, for example.

A DFE for a high-speed press will typically be using multiple RIPs running in parallel to ensure that they can deliver data fast enough. File formats that can hold multiple pages in a single file, such as PDF, are split so that some pages go to each RIP, load-balancing to ensure that all RIPs are kept busy. For very large presses huge single pages or images may also be split into multiple tiles and those tiles sent to different RIPs to maximize throughput.

The raster image processor pipeline. The Harlequin RIP includes native interpretation of PostScript, EPS, DCS, TIFF, JPEG, PNG and BMP as well as PDF, PDF/X and PDF/VT, so whatever workflows your target market uses, it gives accurate and predictable image output time after time.
The raster image processor pipeline. The Harlequin RIP includes native interpretation of PostScript, EPS, DCS, TIFF, JPEG, PNG and BMP as well as PDF, PDF/X and PDF/VT, so whatever workflows your target market uses, it gives accurate and predictable image output time after time.

Harlequin Host Renderer brochure

 

To find out more about the Harlequin RIP, download the latest brochure here.

 

This post was first published in June 2019.

Further reading:

1. Where is screening performed in the workflow

2. What is halftone screening?

3. Unlocking document potential


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How to accurately calculate the ink costs for your digital press

There are many costs that can impact your profitability when running a production digital press, from power consumption to the substrate you’re printing on. One of the most variable costs is ink consumption, which often varies from job to job and therefore can be difficult to estimate. As you might expect, the content to be printed is the key determining factor, but you also need to consider the resolution, screening method, drop sizes and choice of colorants. This can bring quite a challenge for a press shop when quoting for a job, especially if the client is open to hearing a range of options.

Even with a static job that might be suitable for a test print run to get a cost that can be multiplied for the number of copies, it’s still not ideal to have to spend any time or other resources using the actual press. It’s much better to be able to get an accurate ink cost estimate away from the press, which is where our Job Cost Estimator comes in. It’s available as part of our Direct™ software range as well as our Harlequin Host Renderer™ and ScreenPro™ products. It uses the same setup that drives your printer, calculating a very accurate estimate of the ink cost for a specific job. Self-contained, it doesn’t require any connection to your printer, which makes it ideal when you want to give a job cost indication away from the print shop.

The screenshot shows a calculation performed using our Job Cost Estimator for a 1200x1200 dpi version of our two-page Direct brochure, screened with 4-drop pearl.

The screenshot above shows a calculation performed using our Job Cost Estimator for a 1200×1200 dpi version of our two-page Direct brochure, screened with 4-drop pearl. Under Cost Per Page, this is the average cost per page per colorant based on the two pages that were analyzed, with a final row showing the total (All). This is then multiplied by the total pages and the number of copies to get the Cost Per Job for each row.

Obviously, no costs can be determined without knowing how much the inks cost per liter, so you can set these within the application. Similarly, you will need to configure your printhead(s) to specify how many picoliters of ink are used per drop size.

As you can see from the left image above, we have assigned a different printhead for Black called Budget_PrintHead, which will have fewer picoliters per drop size than the Default_PrintHead shown on the right, to represent a possible response to a hypothetical jump in the price of black ink.

The Job Cost Estimator has been designed to be extensible, so it would be possible in future to incorporate other costs, such as paper, or factor in ink used periodically for nozzle refreshing, for example.

If you’d like to know more about the Job Cost Estimator, watch my short demonstration here:

For more information visit the Direct pages on our website: globalgraphics.com/direct

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About the author:

Ian Bolton, Product Manager, Direct
Ian Bolton, Product Manager – Direct

Ian has over 15 years’ experience in industry as a software engineer focusing on high performance. With a passion for problem-solving, Ian’s role as product manager for the Direct range gives him the opportunity to work with printer OEMs and break down any new technology barriers that may be preventing them from reaching their digital printer’s full potential.

Improve inkjet output quality with PrintFlat™

If you print on an inkjet press you’ll know that the problem of non-uniformity or banding is a particularly difficult one to resolve. It’s especially acute on areas of flat tints with the result that printed output is unacceptable to you and to your customers. This means you either don’t run certain jobs on your inkjet press or, in some sectors of the market, are forced to sell your output at a discount.

The good news is that with PrintFlat you have a solution that is quick to deploy and cost-effective, and it can be applied to any workflow with or without a RIP. With more press vendors adopting this technology, watch our new explainer video to see how you might benefit.

Find out more about PrintFlat here.

 

Fundamentally it’s…

8 Fundamentals _black

It’s been a really interesting week chatting to vendors and the press about our new software and services package for inkjet. In case you missed it, we’ve called it Fundamentals because it combines essential software components and engineering expertise that press vendors need to build a Digital Front End.

What’s the big deal you might say?  Well, The Times They Are A Changing to quote Bob Dylan both in terms of the progression of inkjet technology and the swing towards digital printing in the labels and packaging sector which is where we have focussed our initial offering of Fundamentals.

Thanks to our lengthy graphic arts experience – we’ve been supplying software to drive digital presses since 2002 – we are regularly approached by inkjet press vendors either to intervene at some point in an existing workflow or because they’re starting from a blank sheet of paper and need to figure out how to build a Digital Front End for a new press.

If they have an existing DFE a press vendor might be stuck on output quality, or maybe they can’t get the throughput in speed that they need. If they’re building a new press they might not know where to quickly source the components they need. Or often they can’t allocate enough engineering resource to the DFE when they need to. Plus it takes a very special skill set to know how to wire it all together.

How do we know all this? Because vendors tell us so. And Fundamentals is our response to this market demand. It offers best of breed software products with an engineering service that allows the press vendor to address their specific applications.

It will grow, of course. We are already looking at a Fundamentals software bundle for industrial inkjet for example. But the good news for press vendors is that we can do all of the above and then some!