Newspaper Image Processing Tips

The picture has a very important role in the layout of the newspaper. If used properly, it will not only beautify the layout, increase people's interest in reading, but also play a role in finishing touch. The processing of a picture before printing directly affects the effect after printing. Therefore, through years of practice, we have conducted some useful explorations of image processing.

Before scanning the picture, you should first review the picture. The quality of the picture should be known, that is, whether the exposure of the picture is excessive or insufficient, and it is not necessary to go to the network. In this way, the picture can be properly processed during the scanning process because the picture is processed during the scanning process. The level of loss is minimal.

General pictures are scanned in color. If it is a grayscale image, it will be better to use a color scan. The grayscale image converted from color is more hierarchical than the grayscale image directly scanned, especially when the saturation is over 70%. There is a "dash" option on the Chinese-made Lino Color Elite setting panel. If it is a print, you need to select a value here. The higher the print accuracy, the larger the number of pictures to choose. In addition, six options such as "color calibration" can be selected by default and can be selected according to your own situation. The "Color Assistant" in "Calibration" is a very good tool to choose different ways for the pictures, or freely determine the selected values, and adjust the data during the picture scanning process, which will retain more levels and details.

In the Photoshop image processing, we must first set the black and white field and gray balance of the picture. These two factors are very important and necessary. According to different printing needs, the determination of black and white fields is not the same. But the standard is that the black court can not paste the white field can not stop the net. However, in order to ensure a better visual impression after the printing of the pictures, a small area of ​​the net or paste may be considered, but it must not be a large area. If the picture is distorted, we can use the gray balance to restore its color, but the medium gray affects the color of the entire picture, so use it accurately. The mastery of gray balance has the following experience: below 20% or 80%, the CMY value is basically the same; in the middle value part, the MY value is basically the same, but the C value is 10~15% more than the MY value.

In actual operation, the grayscale processing will be relatively simple. There are two methods for exchanging color images into grayscale images: directly using the "mode" function for conversion; or converting a color image to a Lab mode first, then deleting "a channel" and "b channel", and finally converting the image into "Grayscale". In the Chroma Lab mode conversion, the luminance L channel retains more level changes, so the effect will be better. After a grayscale image has been set in a black and white field, it is necessary to pay attention to the level of the image, and the middle tone must be pulled apart. Otherwise, the image will feel foggy, dirty and unclear. The contrast of the middle tone will increase, and it will obviously improve. This situation.

In the process of using Photoshop to process pictures, do not let the picture go around in two modes. Because every time you make a conversion, you will lose some of the details of the original picture. When converting an RGB mode picture into a CMYK mode picture, the separation parameters will play a decisive role in the effect of the picture conversion. The adjustment of color separation parameters will greatly affect the conversion of pictures. Photoshop image processing software has the ability to control color separation parameters. That is, when it is necessary to convert pictures processed in RGB mode to CMYK mode for output, the adjustment of color separation parameters can be reduced in the picture during the conversion process. Loss of color during mode conversion.

If you convert an RGB mode picture to CMYK mode, an intermediate step is added to the operation step, that is, it is converted to Lab mode first. The Lab mode consists of three channels. The L channel represents the brightness. It controls the brightness and contrast of the picture. The colors included in the a channel range from dark green (low brightness) to gray (middle brightness) to bright pink (high brightness). The b channel includes colors ranging from bright blue (low brightness) to gray to yellow (high brightness).

Lab mode is similar to RGB mode, and a mixture of colors will produce brighter colors. Only the value of the luminance channel affects the light and dark changes in color. The Lab mode can be thought of as the RGB mode of two channels plus a luminance channel mode. The Lab mode is device-independent and can be used to edit and process any picture (including grayscale pictures), and is as fast as the RGB mode and several times faster than the CMYK mode. Lab mode guarantees that there is no loss of color in the CMYK range when the color mode conversion is performed.

Processing images in different modes will have different effects, like the Lab mode is helpful for increasing the contrast of the picture, but the use of the amplitude can not be too large, otherwise the picture will be distorted. RGB is the best mode for processing pictures, providing the saturation and brightness of photos, performance levels and other functions are very good, especially good at adjusting the face color of people, will not cause distortion or leveling. However, all pictures must be converted to CMYK mode before printing. Therefore, there are advantages in adjusting pictures in CMYK mode. In this mode, adjusting each color through the channel can prevent the color cast of the picture, and it is also very convenient for determining black and white fields.

Different pictures need different methods of processing. Pictures like traditional Chinese painting must be faithful to the original film, and it cannot change its color because the effect is good-looking. Pictures such as comics and calligraphy are used to ensure that their details are not lost. The use of bitmaps is not only clear, but also has a small picture capacity, which will increase the speed of publishing.

In addition, in Photoshop, there are many useful tools in the "image adjustment", such as "brightness/contrast", "hue/saturation", "optional color", etc. In practice, as long as it is used reasonably, it will be obtained. effective.