Most popular image preparation for electronic colo

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Preparing images for electronic color scanners

the most common problem when using electronic scanners for color separation is due to excessive reliance on manufacturer default settings. Previous generations of electronic scanners required experienced operators to control a complex set of control buttons. Analog scanners or analog/digital conversion scanners need to be manually adjusted, and parameters cannot be pre programmed in advance

preset default parameters include resolution, addition rules, target points for tone reproduction, gray component substitution, and other imaging reference factors. In the past three decades, with the wide application of default settings, color reproduction has become extremely simple and easy to learn

for the process of color reproduction, the three main imaging concepts are tone reproduction, gray balance and color correction, including global and local color correction. In the process of color separation, factors such as color light removal, detail enhancement, under color removal (UCR) or gray component replacement (GCR) should also be considered

cast removal

the original transparencies and copies often have overall color deviation, such as green or blue. This situation can be caused by many factors, including inappropriate films applied under visible light or heated exposure conditions. The electronic scanner provides us with the opportunity to adjust the overall color deviation and correct the color gamut range in the verification process of cyclic torque

detail enhancement

with the gradual popularity of laser scanners, individuals can also sell laser art manuscripts. At this time, the image definition is very high and can be made into three-dimensional images. For desktop and Photoshop users, it is more common to enhance the sharpness of the image through sharpening and multiple sharpening filters. The sharpening filter sharpens the blurred image by increasing the contrast of adjacent pixels. The high-end roller scanner has a feature: it can add a thin white line around the shadow details and a thin black line around the highlight details. This feature is adjustable and is most useful for more complex works of art. Larger detail enhancement should be limited to soft and detailed images (such as skin tones in Portraits). The starting point of detail enhancement of each picture should be specially set

background color removal

since the 1950s, background color removal is often used to reduce the density of yellow, magenta and cyan inks in the neutral gray shadow of the image, and replace it with the density of all black inks. The main advantage of UCR in lithography is that it can reduce the dot enlargement rate and wet overprint. In gravure and offset printing, another advantage is to use black ink instead, which reduces the cost of expensive pigments. As the amount of ink on the printing paper is reduced, the drying speed is also greatly improved

ucr is the pioneer of grey component substitution. UCR is quantified by removing the percentage of density from the maximum shadow. The use of UCR sometimes leads to gray balance problems in neutral gray shadows, and it is necessary to use the increase of ground color to compensate for the lack of color

gray component replacement

the use of gray component replacement (GCR) is a refined and more complex change of background color removal. GCR is usually called achromatic substitution, which can affect the effect of the whole image, and is not limited to neutral gray shadows like background color removal. Different colors and hues are overprinted by different amounts of cyan, magenta and yellow. GCR is based on this theory. The color to be copied is often mainly composed of two subtractive colors, and the third color forms gray pollution. Compared with the other two main colors, the color ink with gray pollution or the weakest color can be reduced or removed, and replaced with black ink

because GCR gray affects the effect of the whole image, it should be controlled by software, and the software provided by different manufacturers is also different. Gray component substitution is often a standard default value in image processing software, which is realized through Adobe Photoshop. GCR is the common name of this process. In addition, it also includes many different names, such as integrated color removal (integr is mainly a single space electronic universal experimental machine, referred to as ICR) provided by Dainippon screen company, polychromatic color removal (referred to as PCR) of crosfield company, and complementary color reduction (referred to as CCR) of linotype/hell company

gcr has the following advantages:

l. reduce the total ink coverage

2 Accelerating the drying of ink can not achieve the output control of small deformation and small experimental force (the sample load is very small, and the drying speed is

3. improve the ink overprint

4. Expand the improvement points

5. When using 50% or more GCR, the cost of ink will be saved

in the past decade, customers' acceptance of GCR technology has been increasing, and swop (description of rotary offset parameters) has also made many improvements to it. Excessive use of GCR in the color separation process will lead to deviation between the color and the original. If nearly 100% GCR is used, any registration deviation during the operation of the printing machine will lead to small white lines

electronic scanner is the first choice of color separation system in the industry at present. The technical support behind the scanner may continue to reduce the price of the scanner. Scanning in commercial applications requires a deep understanding of the image processing parameters in different replication processes

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