Color adjustment of pictures and group editions in small color newspapers
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At present, many counties and cities in China are still only four editions and four editions, and the circulation is about 20,000. Due to the market demand, sometimes some big newspapers print the color newspaper. The same printing machine, processed with the same software, can have a good time difference in the printing quality of small color newspapers, and the printing quality of hundreds of thousands of printed numbers differs greatly. The reason is that the speed of the paper strip of the high-speed rotary machine can reach 9~13m/s, and the number of prints of the small color newspaper is only about 10,000. The color is not adjusted to the best, and the limit of printing scrap is reached. Counting, the printing workers often do things, which makes it difficult to guarantee the quality of the print. How to solve this problem, on the one hand, the technical workers in the printing factory should improve their own quality, the coloring should be accurate, and on the other hand, the typesetting staff must also have a certain cooperation in the pre-press processing of the small color newspaper, so that when printing Toning has become relatively easy, speeding up the color speed of small color newspaper printing, and the small color newspaper will have a relatively good print quality. Prepress processing includes image processing, group editing, output, plate making and other processes. The following two aspects of image processing and group editing, to improve the printing quality of small color newspapers to talk about some views.
The picture plays a very important role in the color report. The beautiful picture can often play the role of finishing touch, giving people the enjoyment of art. In order to get the best printing results, the first thing is to adjust the picture. In the printing of small color newspapers, the prepress processing of pictures is especially important. Only a good picture can make it easy and quick to adjust the color during printing.
1. Original quality
It can be said that if the quality of the image original is not high, although the pre-press processing and the printing process adjustment are fully in place, the picture quality cannot be greatly improved. For this reason, the selection of the original is crucial. The requirements for color picture printing on color pictures are: colorful, rich, accurate, realistic, basically no excessive color deviation; clear layers, good definition, no illusion; moderate contrast, uniform distribution; no scratches, Handprints, dust, creases, etc.
For the original is a photo, try to use no rice photo paper (do not have a variety of lines); if it is a second manuscript, it is best to print the number of lines above 150 lines / inch (exquisite sample, etc.), and do not zoom in For line drawings, the original is preferably the original ink, not a copy. In addition, the image files downloaded from the Internet are generally small, and the precision and definition are not enough. Try to use them as little or as little as possible.
It should be pointed out that in order to meet the above requirements, in addition to the efforts of the image processing staff, it is necessary to get the cooperation of the editors of the newspapers to jointly improve the quality of the originals.
2. Image processing
(1) Processing color pictures in RGB mode. RGB mode is the color scheme used by all optical-based devices, which can represent many colors, especially bright and bright colors. The editing process of a picture often goes through many subtle processes. For example, it may be necessary to combine the contents of several pictures. Since the original colors of the components cannot be the same, they need to be adjusted. Regardless of the effect of the image processing, the operator wants to produce and retain as many subtle effects as possible, making the picture as realistic and rich as possible. Since the color range of the RGB mode is much larger than the CMYK mode, when the image is processed in the RGB mode, a wider color space and more subtle editing effects are obtained throughout the editing process, and these effects are obtained. If used well, most of it can be retained. Although it still has to be converted to CMYK mode and there will definitely be color loss, it is much better than losing the color of the picture from the beginning.
(2) Picture sharpness adjustment. In the adjustment of small color newspaper pictures, sharpening is the most effective means to improve image clarity. Compared with high-end printing, due to limited printing conditions, the color newspaper has a high dot enlargement rate, a coarse mesh, and a large sharpening value, which is advantageous for improving image sharpness, and generally adjusts to a slight outdated screen effect. From the perspective of the hanging network process, sharpening also eliminates the effect of layer loss caused by hanging nets. From this point of view, sharpening is by no means a part that can be done or not, but a necessary part of prepress processing. The degree of sharpening is related to the type of original image and the zoom ratio. Usually, the picture of the character is sharper and the picture is larger. In general, the larger the image sharpening, the higher the magnification and the sharper the sharpening.
(3) Adjustment of picture level. The purpose of the level adjustment should first meet the printing requirements. According to the characteristics of the high expansion rate of newspaper printing outlets, the expansion of the dot in the printing process will be compensated, and the main level will be concentrated in the middle area, that is, 20% to 60% of the visual sensitive area. In the adjustment process, the tonality of the original is maximized to correspond to the tone that can be reproduced by the printing, so that the image is clear and true. Secondly, according to the original content and the hierarchical distribution, the tone of the important part is ensured accurately. Such as clothes, face, etc., must be clear, such as the difference in facial level should not be less than 15%; again, to adjust the value of extremely high or very dark, not large area, generally controlled at 2% ~ 95% about.
(4) Picture color adjustment. The adjustment of the color of the picture is what people usually call the school color. It mainly reproduces the color reflected by the original (not the original itself). In the course of operation, it is mainly to correct the color shift caused by the original or scanning to ensure the color of the main part is accurate. When adjusting the color, make sure that the screen effect is compatible with the final printing effect. It is important to keep in mind that the newsprint has a gradation of 3% to 5%. It is best to open the original digital file against the proofing sample or the more accurate printed product. . At the same time, it should be noted that the color correction should be based on the information displayed on the information board, but not on the screen.
(5) Convert RGB mode to CMYK mode. The picture used for printing the film must be in CMYK mode, so the picture mode should be converted before the film is released. 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 always brighter than the picture in RGB mode. After conversion, you should observe the picture first, and confirm that there is no color cast before outputting. If you feel that you are not satisfied, you should immediately cancel the conversion of this color mode. You must never convert it back to RGB color mode, resulting in irreparable color loss.
The grouping process is also an important aspect of the quality of the color report. The use of the layout color affects the positioning, theme and style of the entire layout. Although most of this is edited, the typesetting staff must use the color reasonably and adjust the color appropriately, thereby reducing the time for adjusting the color during printing and improving the printing quality of the small color newspaper.
1. Image processing in the layout
In the process of grouping, the impact of picture quality is small, but it must not be ignored. First of all, don't zoom in or out easily when you are in the group. Shrinking the image will make the image look poor and the output slow, while magnifying the image will have a greater impact on the image. If you want to change the size, you need to do it in the image processing software. Secondly, we must pay attention to the pressure of the picture. The pressure word can't be too much or too big. Don't use the negative word, otherwise it will affect the picture effect. In addition, the text and pictures should be kept at a certain distance. Do not over-squeeze or loosen, affecting the overall beauty.
2. The processing of shading in the layout
In the small color newspaper, the most difficult to print is the large area of the shading, not the color is not allowed or the color is uneven, which is mainly caused by the coloring of the printing technology workers. How to properly use the shading to make it a part of the layout language is an important part of printing a small color newspaper. First of all, the choice of shading color should be reasonable. For example, the visibility of yellow on white newsprint is low. If the yellow shading is used, it is necessary to use a solid color (that is, a single color with 100% saturation), otherwise it is difficult to have high printing quality; if there is black in the shading, If the words are not hooked, the purple, cyan, green, red and other shadings should be used less. They are less visible to the black characters and should be avoided. Secondly, the shading color should use sub-solid color and solid color in the application, and use less complex color, because the multi-color is four-color synthesis, which means that it needs four times to be printed with reasonable matching, which is increased in the small color newspaper printing. The difficulty of color grading makes the color difficult to print and is prone to color cast. Again, add color blocks to the text, as this will reduce the visibility of the text, and should be avoided if the font size is not large enough. The background color of the text should be based on the premise of not obstructing the reading of the text, so it is advisable to have a small font size with a certain length to make the background in soft and light tones, avoiding the use of dark colors such as blue-green, blue-violet.
3. The processing of text in the layout
In general, the text is black, because black is the most visible in white newsprint, and the color stimulus to the reader's retina is minimal, which reduces the visual fatigue of the reader during long reading. If the content of the text must use colored words, it is generally suitable to use purple, cyan, etc., which are highly visible in white newsprint, and use less visible colors such as gray and red. Basically, yellow cannot be used. The color is the least visible in white, and the color is very irritating, very glaring and looks tired.
The size of the title of the article is generally larger, and the number of words is small. In the application, more high-definition, high-purity colors, such as yellow, red, and orange, are used to attract the reader's attention. At the same time, from the printing point of view, Easy to print. Of course, for the overall needs of the layout, soft pastel shades can also be used.