Transmission manuscript analysis (VII)
4 Key points for calibration of various color editions
the key to reproduce the skin color of a character manuscript ideally and in line with the character's characteristics lies in electronic plate making. In the process of electronic sub calibration, the real skin color, the original skin color and the desired skin color should be organically combined in order to achieve a good replication effect
through research, we can get four key points of electric division and calibration when copying the skin color of people
(1) the yellow version of the highlight calibration should be cut, cut in the red version, and pull out the color level of the face
yellow version is the basic color version of skin color, which plays an important role in the change of facial skin color. The color change, warm and cold relationship and hierarchical texture of the character's skin color all depend on the enhancement or weakening of the yellow version. Its depth, lightness, flatness and budding have a great impact on the whole skin color
the brightness and color of facial skin color will have many opportunities to further study the changes through the cooperation with Masdar, which are caused by the illumination of a certain tone. The reason for the above key points of electrical sub calibration is that only when the yellow version of high light calibration is cut and cut in the red version, can it comply with the law of facial structure, light and shadow, color changes, and show the rich color changes and various subtle pan colors of the face. At the same time, only in this way can the calibration show face 2 The test space is adjustable and can be used to test the requirements of different heights With good rigidity, small deformation, accurate measurement data, the base and beam adopt an integral casting structure, which is reasonable in structure, the workpiece is rigid, and the external decoration is beautiful, ensuring the safety and reliability of all parts The bright and clear layer and realistic texture of the highlights
the reason why this effect can be achieved is that the highlight color of the face is generally skin color plus light source color, showing a bright color of neutral white. The yellow version is calibrated in the red version, and the neutral white with high brightness appears bright. According to the color light principle, the brighter the light is, the bluer its hue is. The highlights on the face and the light receiving part of the middle tone are light blue and purple. Therefore, after the yellow version of the high light calibration is properly set, it can realistically show the color changes and clear hierarchical texture of this part
the standard for the highlight calibration of the yellow version is: the proportion of the neutral white part of the highlight, such as the highlight at the tip of the nose and the middle of the bridge of the nose, that the Yellow cuts out in the red is generally 2% - 3%, if the red is 5%, then the yellow is 2% - 3%. The best cutting degree should be controlled by appropriately raising the part with color level changes in the middle of the face. For example, the middle point of the forehead and the two eyebrow bones are the three highlights of the forehead. The Yellow Version raises it moderately, so that the color level changes of the forehead can be fully reflected. For example, the light receiving part of cheekbones and other parts is generally pink white, and the yellow version is fixed, which can realistically show the hierarchical texture of this part
the color quantity of yellow plate calibration should be accurate, and the accurate point area should be given according to the skin color density of the original, character characteristics, printability and other conditions
(2) the area of the point in the middle of the face should be controlled below 50%
according to the printing suitability conditions of most factories in China, the correct control of middle note of electric sub calibration is an important part of reproducing the skin color of people, and it is also the key to achieve the consistency of tone and improve the printing suitability. At present, most electric scaling only controls two points of the black and white field. This method is not suitable for copying character manuscripts, because even if these two points are controlled properly, the color level of middle note fluctuates greatly. It is also because the facial skin color of some side backlight and backlight color film originals are in the middle tone, which is the key area where the printing time point changes the most. The method of moving the midpoint to calibrate the density value is often used to adjust and control the tone of the person's face. The specific methods are as follows:
① take the inability of the forehead of the face to output experimental data or automatic analysis data as the middle note control point
② based on the point area of the red version
③ convert the forehead of the color reversal film (the density is 1.10 ~ 1.2) to a point area of more than 50%. Because the point area of this density range is generally in the range of 52% - 54%, the points in this range fluctuate greatly, which has a great impact on the skin color. If the red dot on the forehead exceeds 50%, on the one hand, it will cause local tightness, on the other hand, it will affect the ink amount of printing
the above is the contralateral backlight manuscript. As for the smooth and backlight originals, there is no problem. Because the forehead density of the smooth film is generally about 0.9 and below 1.0. According to the standard hierarchical curve, standard black and white field calibration, the red version point is within 40% - 45%, which is ideal. The density of the forehead of the backlight film is generally 1.3 ~ 1.4, which belongs to the middle note dark. According to the standard hierarchical curve, standard calibration or lightness reduction (brightening) calibration, the points of the red version are also about 55%. As the proportion of the points of each color version of the skin color is deep on the whole, it is not a problem
(3) close the two circulating oil tanks on the face, darken the skin color with large area, and the yellow and red spots should be controlled below 80%, about 75%, and 15% - 20% away from the dark color
some side backlit and backlit character images have large dark tone area, high color density and yellowish brown or black tea hue on their faces. During the electric division calibration, the dots of yellow and red plates are more than 80%, or even 90%, which is close to the dot area of deep primary color. Because the hue value of the points in this area changes greatly during printing, even if the printing is carried out according to the standard ink dosage, the dark tone of the printed skin color is also reddish, showing "fire", and is not saturated with the deep primary color, so it is difficult to give consideration to both during printing. If the printing takes into account the skin color and the amount of ink is small, the skin color is OK, but the deep primary color is unsaturated. If the printing takes into account the deep primary color and the amount of ink is sufficient, the skin color will be dark and red. Therefore, there is the third operation point
(4) for the skin color of the forehead, the red version should be lighter than the yellow version. The forehead is a prominent part of the face, which is a large part of the face. Because it is prominent and has few muscles, it is bright after receiving light. According to the facial structure and its color light change law, the skin color of this part must be slightly yellowish, showing a yellow flesh color. Therefore, for the combination ratio of yellow and red points, the red version must be lighter than the yellow version. The general rule is that the red version is lighter than the yellow version by 5% - 10%. The exact data should be determined according to the characteristics of different people's skin color. For example, for white and delicate children and "beauty photos" with face powder, the proportion of yellow and red can be closer, and generally men can increase the proportion. The principle is that the red version cannot be deeper than the yellow version. If the point value of the yellow version is consistent with that of the red version and deeper than that of the red version, it will give people a flat, stuffy and opaque feeling
during calibration, if the face color of some originals is reddish, and the displayed values of the yellow and red spots on the forehead are consistent, take the forehead as the control point, and adjust the dot area of the red version to be lighter than that of the Yellow Version, which not only corrects the reddish skin color, but also brightens the forehead. If the forehead skin color of some originals is locally reddish, it should be partially trimmed by the reviser, so that the forehead skin color can be bright and true
the original of character photography, especially the half length picture taken in close range, is the original with the most problems and the most difficult to deal with in our reproduction. But there are also many rules to follow. As long as we master these rules, we can copy the original manuscript of the skin color of the characters truly, naturally and vividly, and make the quality of printed products excellent
(5) the law of division of labor in various color versions. Although the color combination of facial skin color in various color versions is different for men, women, old and young, there is still a certain law of division of labor in various color versions
the Yellow Version belongs to weak color in color value, but it is very sensitive in skin color combination, which plays a great role in expressing the light sense of the character's skin color and the changes of color brightness, coldness and warmth. When the yellow plate is not handled properly, or the color is used too much or insufficient, color channeling or color deviation will occur. On the cheeks, lips and corners of the mouth, the yellow version should be lower than the magenta version, and on the forehead, the yellow version should be higher than the magenta version. The hair, eyebrows and eyes should be leveled, while the hair strands and eyes can still be dark, and the nostrils and shadows should also be soft
magenta edition is the key edition of skin color, and it is the key to express the connection between muscle part and high, medium and low tones of skin color. The layout should be bright and clean, uniform, moist, light and full. All levels should be connected naturally. The dark tone should not be too deep to prevent color channeling. The red version should be coordinated with the yellow version in order to express the characteristics of the characters. The hair, eyes and eyebrow steps should be slightly leveled. The shape of lips and corners of mouth should be distinguished and should not be hardened. The light receiving parts and bright spots of the face should be treated naturally. The screen angle is 45 ° to avoid the formation of unsightly ripples after 90 ° intersection with the yellow plate
the blue version shows the level of facial contour, the relationship between light and shade, and the three-dimensional feeling of setting off the face. At the same time, it also shows the color changes caused by different light on the face. To deal with the cyan level and color ratio is the basis of true skin color. Its tone should be slightly longer, with a full color distribution, but it should be sharp. Hair, eyebrows, eyes and other black places should be deeper than the yellow version and magenta version, and the spirit of the eyes should be emphasized. Dark tinting takes the cyan version as the basis for the balance of three primary colors to prevent color skipping and color leakage
in a word, as long as we master the basic rules of skin color processing, the face color processing of characters should be both atomic and higher than reality, so that the whole skin color changes in unity and unity in change, and vividly carve out the spiritual face of characters, so as to obtain perfect artistic reproduction effect
information source: Shandong printing
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