User Experience: The Drawbacks of Digital Proofing Software GMG

As a digital proofing software that has just entered the country, GMG has attracted a great deal of attention in the country, and some of EFI's old customers have invested in his arms.

A company started to use bestcolor's proofing software from 1999. After several generations of upgrades, it is more and more unsatisfactory. Especially after the printing of high-level black-and-white photos by some photographers in 2003, the effect of black and white grayscale proofing on efi is not effective. Dare to compliment the new proofing technology in 2004, and finally communicated with GMG. It was almost a lifetime test. After a simple installation and a one-day trial, we found that it was too much compared to EFI. , And not to mention the pursuit of color accuracy, on its black and white restore, whether it is a single black channel, or three-color gray balance performance is perfect! Now and GMG signed two sets of contracts.

After more than a year of use, just as its advantages, its shortcomings have become more and more prominent, and it is highly personal.

1, the initial linear adjustment of the closed paper

As a third-party hardware (printer)-based driver software, openness is one of the foundations of a successful software. All of the software in the public view market has made the perfect match with the printer the most important task of its own: digital proofing. Software prerequisites must also allow paper and ink to be perfectly matched. A gamut space that is larger than the print color is required to get the final accurate simulation of the print gamut space!

GMG's proofing software uses a Linear in generating the printer's characteristic curve. The paper linear curve of mx3, but no matter what paper you use is this one, ask GMG's engineer software to be able to do Linear itself. Mx3: Is this basis linear? A: No! This curve is based on your machine model, or you can download it from the GMG website! I think it's weird. Everybody knows that the cooperation of paper and ink is critical, even the printer supplier. When I buy a printer, ICC characteristic curve of different papers will be provided. Why does GMG have such a universal linear curve? I took a query to the GMG website and found that there are indeed many curves for different machines, but All clearly stated that it is for a kind of paper! It is GMG's own proofing paper!

So is the actual application, as their technical personnel say, this issue is not important for GMG proofing software?

The company did a lot of paper (like the commonly used EP 517, epson digital proofing paper, Pantech, etc.) found this curve provided by Linear. The printer's maximum gamut space generated by mx3 is significantly smaller than the printer's color gamut space on some intermediate toning phases! We all know that in the color reproduction, the intermediate tone color is the most sensitive color of the human eye! Although the software is in the final closed loop correction We can still make the average △E less than 1, but we find that the largest ΔE (between 4 and 7) of the color patches occurs in the middle part! Some papers actually have the largest △E=4. It is 100% M (magenta), this basic color can not restore the average △ E <1 What is the point?

The company's and GMG's engineers also discussed this issue, but they said that only the paper you choose will be sent to Germany. Let the head office do this curve!

Today's ICC-based color management technology is becoming more and more mature. Even the EPSON printer drivers include ICC-based color management: the K3 series (7800, 9800, etc. Open the custom target curve, you can choose the color space you want the printer to simulate! Now the only part that is limited is the paper section - EPSON allows you to use only its own paper in its driver! I am in and When the upper management team of EPSON China headquarters communicated with Japanese EPSON, K3 series printer R&D personnel, they also put forward such suggestions: it is recommended that they open the custom function of the paper characteristic curve ICC in the drive! If this one day becomes a reality, then, So many digital proofing companies how to deal with it? After all, people's drivers can provide free oh!!!

Do not know that GMG does not open the paper linear curve generation is not the same considerations and EPSON - Occupy paper market?

2, closed color characteristics

The biggest difference from other digital proofing software (also the biggest feature of GMG) is that it is not based on the principle of space conversion based on the ICC color characteristic curve, but is based on the conversion of CMYK's 4D color space, and the printer's CYMK color gamut is finished ---> printing. The direct conversion of CMKY color gamut is a direct feature conversion based on specific equipment (printers and printers), which translates to higher accuracy while also bringing a more deadly problem to it and our modern The prepress process control is almost incompatible. We all know that the prepress process now integrates the color management of the ICC color management features. When we provide the ICC characteristics of a printing press, we can use it to guide our entire printing process. All color controls in the copying process: if we put it on a computer, we can get a soft proof on the screen; put it into a printer to get a digital proofing; and put it into the prepress process to get an accurate color separation of RGB----CMYK! Digital proofing software must also consider the integration with the prepress process, while at the same time ensuring the accuracy of proofing. More and more printing companies are beginning to accept RGB is even the color flow of LAB. After converting the color space to the final position of the process, that is, after proofing, the purpose is to minimize the loss of the conversion of the color of the picture. Because the standard of the characteristic file is different, GMG cannot The prepress process for soft proofing, also not integrated into the 3rd party, participates in the accurate color separation of RGB or Lab to CMYK based on ICC standard color management, although it has its own RGB to CMYK color separation software (of course, you have to Money) but the inconvenience is not clear! Who else will not enjoy a free lunch?

3, split-type RIP and driver module

It is entirely because of dissatisfaction with the accuracy of the text printed by this method! GMG's digital proofing rip and the final color management and driver are separate, the intermediate file is a TIFF file format! That is, the RIP job generates a TIFF file from the PS generated by the typesetting software, and then sends it to the rear to perform color space conversion and then drives the printer output. Although it can be done without human intervention by the hot file method, it brings about an accuracy problem and the printed text is special. There is a big difference between small texts and prints! The reason is that the accuracy of the generated TIFF format is limited! We generate 360DPI, 720DPI, and 1440DPI TIFF output comparisons respectively. The accuracy is better than the low-precision TIFF graph. But the RIP time you have to pay is indeed doubled! However, even if the accuracy of 1440dpi and EFI direct drive text effect is still very different!
GMG ColorProof accurate color proofing solution introduction
July 13, 2006 9:17 Source: HC Network Printing Industry Channel

In many inspections of today's most famous products, GMG's proofing solution, ColorProof, is always in the top ten. Practice has proved that it is a market-leading solution for professional proofing. The latest version of the product, GMG ColorProof 04, continues its traditional position and redefines standards.

Professional user's professional tools

GMG ColorProof 04 consists of the following components: GMG ColorEngine, GMG Profile Editor and SpotColor Editor (spot color editor), GMG RIP Serve (GMG image rasterization server) and applied to a wide range of output devices Output module. The important element in the software is its unique "four-dimensional color conversion engine" which, when outputting contract proofs through a variety of output devices, guarantees the best quality. The system can rely on all standard color charts to measure with a spectrophotometer. The device's independent color management file is stored for professional printers. Together with a rapidly developing linearization tool, it makes the system particularly suitable for use in fine proofing. GMG ColorProof 04 supports all current spot color systems (each picture has nearly 64 independent color channels), and is compatible with the standard ICC profile. The ICC Profile can be combined with the GMG device to link into a profile.

New features of GMG ColorProof 04

GMG ColorProof 04 includes new simple installation work that allows users (users) to quickly get very good proofs. When applying the standard profile, the user only needs to run a simple printer calibration procedure. This program ensures that the same results are obtained when using different modes of printers. The redesigned user interface makes the operation in the GMG ColorProof more intuitive, allowing users to achieve faster speeds. In the GMG Profile Editor (GMG Color Management Editor), the selective correction function is improved when reading color values ​​from a spectrophotometer in this way.

Another new feature in the GMG SpotColor Editor is support for test charts, including the office Pantone spot color library. The new printer calibration Wizard does not make it easier to calibrate the output device with the Profile Editor. The license for Fogra Media Wedge is also included in GMG ColorProof 04. GMG ColorProof 04 is the most cost-effective, high-target proofing solution on the market. It adapts to all contract proofing needs, including color accuracy and reproducibility.

GMG Dotproof - for accurate halftone proofs

GMG Dotproof allows users to create halftone proofs by printing color-accurate binary TIFF image data that is obtained from image settings or CTP RIP while maintaining the original screen information. This makes the problem of prints visible only on halftone proofs discovered early. For example, moire and gravure errors. DotProof is particularly useful for CTP workflows. Potential problems can be identified before the plate is generated, which also saves time and costs.

GMG FileOut —— Conversion of CMYK to CMYK

The GMG FileOut module enables conversion from one CMYK color space space to another CMYK color space space while maintaining the integrity of the black channel. For example, offset printing data is automatically converted into gravure printing data.



Source: Chinese Printing Community