Color adjustment of pictures and groups in the hot

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Color adjustment of pictures and group editions in small color newspapers

at present, many county and city newspapers in China are only four editions, with a circulation of about 20000 copies. Due to market demand, sometimes they have to print color newspapers at some large newspapers. Using the same printing machine and the same software for processing, the printing quality of small color newspapers is different from that of hundreds of thousands of color newspapers. The important reason is that the paper tape running speed of the high-speed rotary machine can reach 9 ~ 13m/s, but the printing number of small color newspapers is only about 10000 copies. Before the color is adjusted to the best, it reaches the limit of printing scrap, and the printing workers often make do with it, which makes it difficult to ensure the printing quality. How to solve this problem, on the one hand, the technical workers in the printing factory should improve their own quality, and the color matching should be accurate and fast. On the other hand, the typesetters should also have a certain cooperation in the pre press processing of small color newspapers, so that the color matching during printing becomes relatively easy, and the color matching speed during small color newspaper printing can be accelerated. In this way, small color newspapers will also have a relatively good printing quality. Prepress processing includes image processing, plate assembly, output, plate making and other processes. Here are some views on improving the printing quality of small color newspapers on the adjustment of image processing and plate assembly

pictures play a very important role in color newspapers. Exquisite pictures can often play the role of the finishing touch and give people artistic enjoyment. In order to obtain the best printing effect, the first thing is to adjust the picture. In the printing of small color newspapers, the pre press processing of pictures is particularly important. Only a good picture can make the color adjustment convenient and fast

1. Manuscript quality

it can be said that if the image manuscript quality is not high, although the prepress processing and printing process adjustment are fully in place, the image quality cannot be greatly improved. For this reason, the selection of originals is very important. The requirements for color pictures in color newspaper printing mainly include: bright colors, rich, accurate, realistic, and basically no excessive color deviation; Clear layers, good definition, not empty or hairy; Moderate contrast and even hierarchical distribution; The photos shall be free of scratches, fingerprints, dust, creases, etc

if the original is a photo, try to use rice free photo paper (do not have all kinds of lines); If it is the second original of a printed matter, it is best to use a printed matter with more than 150 lines/inch (exquisite samples, etc.) and do not enlarge it; For line drawings, it is better to use the original ink manuscript rather than a copy. In addition, the downloaded image files are generally small, and the accuracy and clarity are not enough. Try to use them less or not

it should be pointed out that in order to meet the above requirements, in addition to the efforts of image processing personnel, we must get the cooperation of newspapers to jointly improve the quality of image originals

2. Picture processing

(1) process color pictures in RGB mode. RGB mode is the color mode adopted by all devices based on optical principles. It can express many colors, especially bright and bright colors. The processing of pictures often goes through many subtle processes. For example, it may be necessary to combine the contents of several pictures. Because the primary colors of each component cannot be the same, they need to be adjusted, and so on. No matter what effect the image processing wants to achieve, the operator hopes to produce and retain various subtle effects as much as possible, so that the image has real and rich details as much as possible. Because the color range of RGB mode is much larger than that of CMYK mode, when processing pictures in RGB mode, a wider color space and more subtle and variable effects will be obtained in the whole processing process, and most of these effects can be preserved if used well. Although we still have to switch to CMYK mode in the end and there will definitely be color loss, it is much better than losing the color of the picture at the beginning

(2) picture sharpness adjustment. Sharpening is the most effective way to improve the image definition in the adjustment of small color newspaper pictures. Compared with high-end printing, color newspapers have limited printing conditions, high dot enlargement rate, coarse eyes, and large sharpening value, which are conducive to improving image clarity. Generally, it is only necessary to adjust the screen effect to slightly out of date. From the perspective of hanging technology, sharpening can also eliminate the level loss caused by hanging. "A technical director of a waterproof enterprise told Caijing. From this point of view, sharpening is not an optional link, but a necessary part of prepress processing. The sharpening degree is related to the original image type and zoom magnification. Generally, the sharpening degree of the figure manuscript image is smaller, but it can be larger for the landscape manuscript. Generally speaking, the sharper the image is, the higher the magnification is, and the deeper the sharpness is

(3) adjustment of picture hierarchy. The purpose of level adjustment should first meet the printing requirements. According to the high expansion rate of newspaper printing points, the expansion of points in the printing process should be compensated, and the main levels should be concentrated in the middle area, that is, 20% - 60% of the visual sensitive area. In the process of adjustment, that is, to make the tone of the original correspond to the tone that can be reproduced by printing to the greatest extent, so as to make the image clear and true. Secondly, according to the content and level distribution of the original, ensure the accuracy of the tone of important parts, such as clothes, face, etc., be sure to have clear levels, such as the level difference of the face should not be less than 15%; Thirdly, you should adjust the value of extreme highlights or extremely dark tones, and do not use large areas. Generally, it is controlled at about 2% - 95%

(4) adjustment of picture color. The adjustment of picture color is what people usually call color correction. It mainly lies in reproducing the color reflected by the original (not the original itself). In the process of operation, it is mainly to correct the color deviation caused by the original or scanning to ensure the accuracy of the color of the main part. When adjusting the color, it is necessary to ensure that the screen effect is compatible with the final printing effect. Keep in mind that the paper has a gray scale of 3% - 5%. It is best to compare the proofing sheet or more accurate printing product, open the original digital file, and compare and calibrate the color. At the same time, it should be noted that the color correction adjustment should be based on the data displayed on the information board, not just on the screen display effect

(5) RGB mode helps to promote the transformation of system governance into CMYK mode. The pictures used for printing must be in CMYK mode, so the picture mode should be converted before printing. It should be noted that some color changes will occur in the picture when the picture mode is converted. The picture in CMYK mode is never brighter than that in RGB mode. After conversion, you should first observe the picture and confirm that there is no color deviation before output. If you are not satisfied, you should immediately cancel the conversion of the color mode, and never convert it back to RGB color mode through conversion, causing irreparable color loss

the publishing process is also an important aspect that affects the quality of color newspapers. The use of layout color affects the positioning, theme and style of the whole layout. Although this is mostly decided, the typesetters must make rational use of colors and adjust colors appropriately, so as to reduce the time of color adjustment during printing and improve the printing quality of small color newspapers

1. The treatment of pictures in the layout

in the process of composing, the influence of picture quality is small, but it must not be ignored. First of all, don't easily enlarge or shrink the picture when composing. Reducing the picture will make the picture effect worse and output slower, while enlarging the picture will have a greater impact on the picture effect. If you have to change the size, you need to do it in the picture processing software. Secondly, pay attention to the embossing of the picture. The embossing should not be too much or too large. Don't use negative words, otherwise it will affect the effect of the picture. In addition, the text and pictures should be kept at a certain distance, not too crowded or too hot. Various adhesives can still be used for loose bonding, which will affect the overall aesthetic feeling

2. Treatment of shading in the layout

in small color newspapers, the most difficult thing to print is a large area of shading, which is either inaccurate color or uneven color, which is mainly caused by the inaccurate color matching of printing technicians. How to use shading correctly and make it a reasonable part of the layout language is an important part of printing small color newspapers. First of all, the choice of shading color should be reasonable. For example, the visibility of yellow on white paper is low. If you use yellow shading, you need to use pure color (that is, a single color with 100% saturation), otherwise it is difficult to have high printing quality; If there are black words in the shading, but the words have no edges, it is necessary to use less shading such as purple, cyan, green, red, etc. they are less visible with black words, which should be avoided. Secondly, in the application of shading color, we should use more sub pure color and pure color, and less complex color, because complex color is a four-color synthesis, that is to say, it needs four reasonable matching printing, which increases the difficulty of color matching in small color newspaper printing, making the color difficult to print accurately, and prone to color deviation. Thirdly, it is against printing color blocks on the text, because it will reduce the visibility of the text. If the font size is not large enough, it should be avoided. The background color of the text should be on the premise that it does not hinder the reading of the text, so it is appropriate to use a soft and light tone as the background for a certain length of small-sized text, and avoid using dark tones such as blue-green and blue purple

3. Text processing in the layout

generally, the text is black, because black is the most visible in white paper, and the color stimulation to the reader's visual film is the least, so that the reader's visual fatigue is reduced in the long-term reading process. If the text content must use colored words, it is generally suitable to use purple, cyan and other colors that are highly visible in white paper, and use less gray, red and other colors with low visibility. Basically, yellow cannot be used, because this color has the lowest visibility in white, and the color irritation is very high, very dazzling, and looks tired

generally, the font size of the title of the article is relatively large, and the number of words is small. It is more in use. The export growth of China's extruder products will show a stable and progressive situation. Use some high-definition and high-purity colors, such as yellow, red, orange, etc., to attract the attention of readers. At the same time, from the perspective of printing, it is also easy to print. Of course, for the overall needs of the layout, you can also use some soft light tones

source: printing information

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