Color levels, that is, histograms, histogram function. is a method of calculating and expressing photo exposure by counting the number of dark and dark pixels in the photo.
Color levels can be divided into different channels to adjust, the network popular one of the well-known inversion of negative impulse is through the channel to adjust the level of color implementation. But I usually only use the color gradient to adjust the RGB channel. That is, use the color order to correct the contrast of the picture.
Just look at an example. The picture below, the whole is a little less exposure, so the overall picture is a bit gloomy.
Take a look at the color map of this photo. Obviously, the histogram is biased to the left, and the rightmost is a large blank. The meaning of a histogram is that the left side represents the dark part, and the right side represents the light part. The histogram is concentrated on the left, and a large margin on the right shows that the bright pixels of this picture are not many, that is, the overall lack of exposure.
The way to adjust is simple, drag the rightmost white triangle arrow to the far right of the bar chart. The implication of this approach is to remove the blank data and make the histogram wider. The action method is as follows:
As simple as that, the exposure to the photo is back to normal. Look at the color adjustment before and after the changes are more obvious:
Look at the second example, it is also a very simple color scale adjustment.
Open a picture and look at its color bands. This time, not only the right side of the blank, left also empty a piece. What do you mean? Hey, this color level distribution shows that this photo exposure is good, the column is centered in the middle, because the content of the light and shade contrast is not too large, so the two ends of the histogram left a small piece of space.
Since the photo exposure is normal, do you need to adjust the level of color? Haha, tube it, adjust to see the effect again. Or Efaro, drag the small triangles at both ends to move them to the sides of the histogram. The following figure:
Look, the effect is obvious, the photo is brighter and more layered than the original!
What is the reason for this? I think that sometimes a person wants to get, not only the recognition of the truth, but also need to be recognized by the self-worth of reality. The extended gamut may deviate from the reality of witnessing, but it is more pleasing to your vision. Similarly, do not only use histogram to judge the exposure of photos, it is only a reference, subjective feelings and expressions, is the cold machine, the cold code, and even your friends and relatives can never replace you!