How to make high-quality image II by the hottest p

2022-08-15
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How to make high-quality images in the printing system (II)

deal with white and black in the color map

white and black in the color map are not only important colors in the picture, but also with black and white tones, the color is thick and pure. Colorists believe that there is neither absolute white nor absolute black in the world. No matter how bright the "white" is or how dark the "black" is, it has a certain color tendency, but on the specific picture, exaggerated white and exaggerated black can appear. Therefore, we must pay attention to the black and white tones in color pictures when copying, which is an important part of improving the artistic effect of images

at present, most operators only pay attention to the adjustment of color, and ignore the treatment of black and white. Therefore, white objects are often treated as a piece of white, completely losing the hierarchical texture of white objects; The guide puts forward three key development directions, and the solution to this problem is:

1 Improve the understanding of the importance of white and black tones in color pictures

as we all know, black-and-white photos have more visual strength than color photos, because the difference in reflectance between black and white is much larger than that between any color. According to the determination of scientists, the contrast between colors, even the strongest contrast between primary colors or complementary colors, is much weaker than that between black and white. For example, compared with black-and-white juxtaposition, the former can only reach 40% of the latter; compared with red and blue juxtaposition, the former can only reach 23% of the latter; compared with blue and green juxtaposition, the former is only 19% of the latter, This is why black and white works are sometimes brighter than color works. Therefore, processing the white and black in the color map during scanning can not only realistically show the hierarchical texture of various white and black objects, but also highlight the visual contrast of light and dark

2. Essentials of dealing with white objects

White is called polar color in chromatics. Dealing with white in color pictures can not only show the texture characteristics of various white objects, but also be eye-catching and give brilliance in the bright place

(I) due to the influence of light source color, the hue changes of various white objects in color photography pictures are extremely rich. Before processing, it is necessary to fully understand the texture characteristics of various white objects, and then adjust the processing according to different texture characteristics, such as white paper, white clouds, white flowers, white silk, white jade, white porcelain, etc. their texture characteristics are different, and the setting and adjustment should be different. The whiteness of white paper can be handled lighter; The whiteness of white jade and white porcelain should show the sense of jade and porcelain quality, such as some monochrome porcelain such as shadow blue, azure and white glaze. In order to reproduce this texture, when scanning and setting, we should maintain the cyan gray in the high light area. What is the development prospect of "king of new materials" graphene in China? Hierarchy. However, in some of these porcelain albums, the porcelain color of various white porcelain bowls, white porcelain vases and other utensils, which are the largest research and production base of functional membrane materials in Zhejiang Province and mainly in middle note, is printed into a piece of white, as thin as white paper. The bright tone is only 3%-5% of version C. The M and Y versions are unique, and several of them are unique even version C, completely losing the sense of porcelain quality

(II) the white of art image artworks is more characteristic. For example, in oil tanker and gouache, white is reflected by covering it with pigment, which is both white and textured. Therefore, when setting, it is necessary to use neutral white composed of three primary colors to express, and only local extremely high light can be eliminated. In watercolor painting, white is reflected by setting aside the white of watercolor itself. At least one part of each watercolor painting is pure white, so as to make the picture bright and clear. Therefore, when setting, it can be absolutely white for local highlights. Da Vinci once said, "the whitest part of a painting should be as valuable as a gem." It means that there are few places in the painting, which is a special effect pursued by painters. Therefore, when setting the scanning, we must show it carefully

(III) at present, white objects of many prints often appear color deviation and exposure, which is due to the lack of gray balance awareness of some operators. For high gloss white objects that need to be layered, they must be set according to the proportion of gray balance point value, such as c5%-6%, m3%-4%, y3%-4%. If the white is warm, the dot ratio of the three color plate can also be close, but one color plate must not be missing, otherwise it will be biased and exposed

3. Essentials of dealing with black objects

black is at the ultraviolet extreme of the spectral band, which is called polar color in chromatics. Dealing with black in color pictures can not only show the texture characteristics of various black objects, but also fully show the heaviness of the picture, and set off the purity and brightness of the color

(I) black objects in color photographic pictures often cause black turbidity due to the influence of environmental color. When handling, you should first understand the texture characteristics of various black objects, and then adjust them according to different texture characteristics, such as black steel, black camera, black leather coat, black sweater, black silk, black hair, etc. their texture characteristics are different, and the adjustment should be different. For example, for objects such as black steel and metal, the color can be heavy but not light. To show its sense of weight, the black solution should be used when setting: install the hydraulic cylinder, and the point value can reach 90%. At the same time, remove the three primary colors appropriately, and the sum of the four-color version is about 320%. The black leather clothing should not only show the smoothness and thickness of the leather, but also have the texture level of the leather clothing. When setting, we should make full use of the black version to make the hierarchical texture, and the color amount is 85% - 90%. The gradient can be extended to ensure rich levels of middle note and bright tone. Sometimes, you need to use Photoshop lasso tool to hook out the skin and adjust it with black version level curve. As for objects such as black silk, it mainly shows its smooth and delicate texture. When scanning, the four-color version should be soft and delicate, the contrast should not be too large, and the definition should not be overemphasized

in actual production, because the dark tone of the photographic picture is easy to be biased, the object is black and impure. Therefore, the ucr/uca function is used to correct the deviation, so that the three primary color version can achieve the effect of neutral black, and then the black version is mainly used, so as to achieve the effect of pure black and better express the texture level of black objects

(II) the dark tone of art pictures of art is an important part of image plastic art. The black color in them changes rich due to the different characteristics and styles of various paintings. Different treatments should be made when scanning settings, for example: Traditional Chinese paintings are mainly ink, and the ink color is pure. Among them, the ink paintings should adopt GCR process, and make a long tone black version, so that the whole picture level is rich, and the black version at the scorched ink can reach 95%-100%. The color ink paintings, whether heavy color or light color, should adopt UCR process, K95%, C70%, my60%, and the sum of the four colors is about 280%. However, the reproduction of some traditional Chinese paintings now mainly adopts the three primary colors, and the black version is a short tone skeleton process, which causes ink color deviation and exposure, which should be improved as soon as possible

some inks and gouache paintings mix black with other colors, which are not pure black. Therefore, the setting should be based on three primary colors, C95%, m, y%, K70%, and cannot be as deep as the black version in the photographic picture. Some watercolor paintings are almost a unique taste expressed in pure black. Therefore, the black version should also be used for reproduction when setting, which is generally 75% - 80%. At the same time, UCR method is used to reduce the amount of three primary colors of ink. Because the color ink of watercolor painting is light and elegant, the point values after removal are C65%, M55%, y55%, and the sum of four colors is better to be 250% - 260%

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