How to use the scanner's original correction function to process pictures (1)

Most operators use the scanner to scan the image, adjusting only the resolution and scaling options, and the rest use the default settings. Practice has proved that this does not give the best scanning results. In particular, when the original image is defective, the scan results are even less ideal. When scanning a defective image, how can you take advantage of the scanner's best performance and sweep out higher quality images? This requires careful analysis of the original condition, making full use of some original correction functions provided by the scanner and carefully adjusting the scanner's default settings.

First, the exposure of the picture is not allowed

Brightness and contrast are adjusted during scanning, and overexposed images look white because the brightness is too high; underexposed images look dark because the brightness is too low. At the same time, the images lack levels and the details are not rich. At this time, we can drag the sliders on the brightness and contrast sliders to make the image brightness moderate and the contrast suitable. Since brightness and contrast adjustments work on all pixels in the image, care should be taken in adjusting them. For example, the main information of a picture is in a dark area, making it brighter to make details more visible. However, if you use the brightness adjustment function to brighten all areas, you will lose all the details in the brighter area.

Second, color cast pictures

Adjust the color balance when scanning, if the image is somewhat color cast, you can use the color balance option to change the overall tone of the image. When the color cast is not serious, you can select the "Automatic Color Balance" option and let the software automatically correct. If the color cast is serious, you must manually adjust it. The color of the scanner is mainly a mixture of red, green, and blue colors. The scanner provides adjustment functions for each of the three basic colors. The adjustment options include three sliders: red, green, and blue. To adjust the image color, simply drag the slider on the slider to the color you want to add to the image, or drag the slider away from the color you want to reduce. To make color adjustments, you need to master some chromatic knowledge, especially the principle of complementary colors: two colors that are in relative positions on the color wheel are called a pair of complementary colors, such as red and cyan, green and magenta, and blue and yellow. Complementary colors. The so-called complementarity is the reduction of a color in an image, which inevitably leads to the increase of its complementary color. It is absolutely impossible for a color and its complementary color to increase or decrease at the same time.

Third, the lack of hierarchy of pictures

The gamma value is adjusted during scanning. The gamma value affects the tone of the middle value of the graph or the gray level of the middle level. By adjusting the gamma value, the brightness value of the midtone grayscale of the image can be changed to increase the intermediate level of the image, without having too much influence on the dark and light levels. Entering a larger number will increase the range of midtones. This will result in less contrast and more detail in the image where the midtones account for a large proportion of the image. Entering a smaller number will reduce the range of midtones. Doing so will increase the contrast of the image and reduce the details of the image. When the curve moves down, the corresponding pixels of the image darken; when it moves up, the corresponding pixels light up. Its adjustments often need to be used together with brightness and contrast to achieve satisfactory results.

Fourth, the composition of the picture is not ideal

Scanning should be carried out with a reasonable cut. Pictures with inappropriate pictures often have a cluttered background, unobtrusive subjects, or skewed scenery and poor visual effects. During the scanning, the original image may be selected by selecting the scanning range as required, and the skewed image may be corrected for artistic re-creation. The specific operation is to select "scan size" as "user-defined" mode in the scan setting options, and then select the area to be scanned by dragging the selection box in the preview image window. To do this, hold the left mouse button down at the corner of the area to be scanned, drag the marquee to the opposite corner of the scan area, and release the left button. In this way, the scanner will automatically scan only the selected area. Pictures with skewed scenery can be corrected by using the "rotate" function.

Fifth, the printed picture

The use of the descreening function is used during the scanning process. The printing field uses the hanging screen printing technology. It depends on numerous small and large dots to represent the brightness of the image.