How to improve the contrast effect of pictures II

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How to improve the contrast effect of the picture II

when adjusting this picture, you also need to set the highlight and dark tone. In this picture, there is an important object, which occupies most of the area in the picture. We need to adjust the details of the tiger, so we will lose some details of other areas

when adjusting this picture, it is also similar to adjusting the above cat picture, except that it needs to be adjusted in four channels. The black channel is like a picture of a white cat, the green and product channel is like a picture of a gray cat, and the Yellow channel is like a picture of a black cat. With this in mind, we can adjust this picture using a curve similar to that in (Figure 1)

in the black channel, the tiger is in the bright part; In the green and magenta channel, the tiger is in the middle part; In the Yellow channel, the tiger is in the dark part. With the help of the dropper tool and the color data displayed on the information panel, the tiger is positioned on the curves curve. The more accurate the positioning is, the more accurate the color adjustment is, and the less impact on the background is. Adjust the part of the tiger on the curve to be steep

most people choose tigers and adjust them without affecting the background. No matter how carefully you choose, this effect doesn't seem natural. Only the adjustment method of curves curve is suitable for eyes

we know that a color can be seen differently by human eyes due to the different colors around it. Please pay attention to the color of the water area where the tiger steps in (Figure 3). This is an example

only human beings have the sense of visual contrast at the same time. When a tiger steps into the yellow water downstream with yellow banks, it becomes a timber and trades in large quantities; Although the short lumber price has support for the coke price, we will find that the water has a slight color change

after adjusting this picture, we not only improved the contrast of the tiger, but also changed the color of the water to make it greener. Many experts may say that this is nonsense; There is no respect for the original! Just because a tiger steps into the water, the water will not change its color

however, this is exactly the case. When a tiger steps into the water, the water does change its color. This is why the picture below (Figure 3) is more natural

in (Figure 3), the tiger is the most important. It can adjust other objects to make the contrast smaller and the relationship is not too big. In (Figure 4), it is completely different

figure 4 The above picture shows the civet cat in the original. Obviously, it is an important object in the picture, but the snow scenery can not be ignored. In the middle picture, the contrast of civet cat is adjusted to be larger to maintain the snow scene. The following figure shows the loss of snow, increasing the contrast of civet cat

the contrast of the civet cat picture can also be improved by using the method of improving the contrast of the tiger. However, in this picture, civet cat has more gray components than tiger, and all CMY channels are similar to the gray cat diagram in (Figure 1). If the curve of "s" shape is applied in the three channels of CMY, the civet cat in this figure will get a lot of details, but the snow will be lost. And the snow scene is also very important in this picture

so now, the more details of snow scenery are lost, the more details of civet cat are obtained. The more you want to improve the contrast of civet cat, the more you need to adjust its curves downward. The more you do this, the more level the snow becomes. When adjusting this picture, it is necessary to take into account the increasing requirements of civet cat and snow scene plastic calender in terms of safety, environmental protection and energy saving, that is, the brown and gray parts in the curve (Fig. 5) should be adjusted as steep as possible. Obviously, the picture in the middle (Figure 4) is much better than the picture above. Is the bottom picture better? Adjust the curve of these two pictures as shown in Figure 5

Figure 5 adjusts the curve used in Figure 4. The range of civet cat on the curve is represented by brown, and the range of snow scene on the curve is represented by gray. Note that in the following curve, the curve of the snow part becomes relatively flat, which improves the contrast of the civet cat and loses the snow

picture adjustment experts always adjust pictures by discarding some levels to improve the contrast of important parts

if the picture is a very complex picture, it should not be based on intuition, but should be carefully analyzed. It is necessary to always write down some color data on the paper and then evaluate its brightness change. It is worthwhile to spend more time, because you can find many useless colors and throw them away

let's analyze it (Figure 6). First, let's take a look at its highlights and shadows

Figure 6 the upper figure is the original, red. The curve in this figure is used for adjustment, which also increases the contrast for the roads beside the swimming pool and the number of swimming pools

since we don't care whether there is a dot on the shirt, it should not be used as a highlight. In fact, I didn't choose the sunshade as the highlight. I tried the recliner in the distance, 12c11m24y. The dark tone doesn't have so many choices. Nothing is grey except that the lounge chair is neutral grey. The person in the picture is too small for us to accurately measure his skin color

however, there is another known color that we can refer to. Although we can't tell exactly what color the tree in the picture is, it must be green

this is not the case with the trees in the original. The typical value measured is 57c64m100y38k. This is a dark yellow, similar to orange, not green at all. We don't know how much to adjust, but it is certain that the magenta value needs to be reduced and the green value needs to be increased

when adjusting curves, we also need to consider improving the contrast. The content of this picture is quite rich. The stone carvings on the swimming pool, trees and the edge of the swimming pool are important parts to improve the contrast. Position these objects on the curves and adjust these parts to be steep

in addition to brightening the highlights, we also need to make the curves curve steeper in these areas. We can adjust the curves curve in the magenta channel downward

cyan is an unwanted color in stone carvings, so the brightest part of the curves becomes flat. The swimming pool and the tree are located between the middle and third quarter tones, which makes this part steep and helps to improve the contrast between the two. Darker and quarter tones lose detail

fuchsin channel is difficult to adjust. If the tree wants to turn green, it needs to adjust its center downward. However, in this case, the dark part will also turn green. We do this by moving the rightmost point on the curves curve to the left, making the darker gradient on the curves curve steeper. Unfortunately, this cannot be done here. Some sunbathers wear red shirts with a value of 90m or higher. If you move this point to the left too much, you will lose too much hierarchy. The highlights in this curves curve become steeper to adjust the stone carving

yellow has little effect on the contrast. In this picture, it is adjusted steeply to produce color change in the swimming pool. Because the swimming pool and stone carvings have relatively few yellow colors, this curves curve is simpler than the other three colors. All you need to do is adjust the middle step up

black is also easier. Trees are dark, and other objects are bright. And there is no other object in between. Therefore, the two ends of the curves curve are adjusted to be steep, and the middle step is adjusted to be flat

it should be remembered that the method of digital adjustment of pictures is good. However, after using curves to increase the contrast of the picture, many details of the picture will be adjusted


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