Photoshop tips-Color adjustment tips by: Source:

Photoshop is an image processing software that everyone is familiar with and often uses. Its powerful image processing functions are indeed unmatched by other image processing software, the latest Photoshop 6 closely integrates traditional graphic design with Web image production. The extremely powerful photoshop6 will allow graphic designers to experience the fun of graphic design and more easily present their ideas on the screen. Of course, to learn phtoshop 6 well, in addition to being familiar with the basic functions of the software, you must master the skills you actually use. It will make you more comfortable in the image processing process, spend the least time doing the best. Mastering more of these skills will be the only way to move you towards Advanced Photoshop applications. OK, no matter new or old, let's master the essential skills in practical applications, pave the way for our creation.

Chapter 1 color adjustment skills

First of all, it should be noted that the most basic skill in Photoshop is the color adjustment technique, which is also a housekeeping skill on top of other graphics processing software by Photoshop. To make exquisite images, the application of the color pattern and the adjustment of the color are essential. Next we will introduce the techniques in the color adjustment and reiterate that we will not introduce the basic knowledge of the color, we only talk about skills.

First, double-click the left mouse button in the blank area to open a file (this is a trick. Many friends may still use shortcut keys or menu commands, right ?), Then we need to have a color understanding of this image so that we can create it later. How can we calculate the size and pixel of an image? And lists several important information calculation formulas.

Total pixels:

Total number of pixels = width x height (in Image Watermark)

File Size:

File size = total pixels x unit pixel size (byte)

How is the unit pixel size calculated? In the most common RGB mode, one pixel equals three bytes, while in the CMYK mode, one pixel equals four bytes. In the gray mode and dot matrix mode, one pixel equals one byte.

Print size:

Print size = total pixels/set resolution (BPI)

Always know how big the image is to be printed? When creating a new file, you must remember the change rate you set. For web images, 72bpi is enough, while for printing and publishing, resolution is more important, generally twice the number of print Network cables (LPI. With this formula, we can easily define the resolution before creating a file. In addition, resolution changes from low to high, because the total number of pixels does not change, so the image quality may deteriorate. Therefore, we recommend that you set the resolution to a higher level when defining file attributes in the initial stage, changing the image size from high to low will not cause image quality deterioration.

After learning about the basic information of the file, we will make some adjustments to the color. Generally, we use the RGB mode to make a picture, because it is the most similar to the way we usually watch the color, make the chart more intuitive. However, when printing images, we have to use the CMYK mode for printing. Therefore, converting the RGB mode to the CMYK mode is an inevitable process, we should still make a graph in RGB mode, and then convert it to CMYK mode for printing after processing, because it is impossible to use many functions of Photoshop in CMYK, this imposes great limitations on image processing. In addition, the image in CMYK mode is 1/3 larger than that in RGB mode. OK, switch to the RGB mode. Let's start our creation.

When we input an image through a scanner, it is always a headache for color distortion, but we can make up for it through a series of Color adjustment techniques. First, adjust the Color Order of the image. Open the adjust-levels level adjustment dialog box. View the pixel distribution chart of the image. The histogram represents the color order distribution of the entire image or the selected area, while the horizontal axis represents the color order value, from 0 to 255. The vertical axis indicates the number of pixels in its color order. Does it look like a mountain? When the mountains are high, there are many pixels in the color order. On the contrary, there are fewer pixels.

 

Figure 1

Mountains are distributed on the right, indicating that there are many bright images.

The mountains are distributed on the left, indicating that there are many hidden regions in the image.

Mountains are distributed in the middle, which indicates that the image has many tones and lacks color comparison.

Mountain image combs indicate that the color order of the image has a hop level. In some cases, pixels of certain levels are insufficient to express gradient and smoothness.

When you think the image is too bright and too eye-catching, you can reduce the color order value in the input leves, or pull the color slider to the left, in this way, the image will be dimmed. Do not worry about making changes, because if you do not agree, press the Alt key and the cancel (cancel) button will change to the reset (reset) button. Click it, the image changes back to the initial state.

You can use a straw tool to visually adjust the Color Order of the image. The three straw tools represent the dark, middle, and bright parts respectively. Click one of them and pick up the color on the image to change the corresponding slider position in the input. The three tool pairs should have three points, the dark straw corresponds to the black spot, the middle color straw corresponds to the neutral point, and the Bright straw corresponds to the white point. You can set the black, white, and neutral points to define the dark, bright, and neutral colors of the image. Then, by adjusting the color slider, we can expand the color level range. When the color level of the image obtained through the scanner is compressed, you can increase the dark area and bright area of the image by setting black spots, white points, and then expanding, to enrich the color level of the image, it also increases the image contrast between light and shade. (Note: The straw tool is invalid in lab mode)

Many people like to convert the image into a gray-scale mode to create black and white images, but after this, many commands that can be used in RGB mode will not be available, in fact, there is a better way to make black and white images: Adjust the image to grayscale through image (image)-adjust (Adjustment)-desaturate (desaturation, in this way, the image will also show black and white colors, but the actual image remains in RGB mode.

　
Figure 2

Do you want to change the person in the photo to a different color? Sorry, this is not easy to do. It is impossible for me to get a selection box at and then color it? Oh, of course not. You only need to use the color replacement command in Color adjustment. Open the adjust-replace colro command, and the following dialog box appears.

　
Figure 3

Note that the three straws, from left to right, are probe bars, select probe bars, and subtract probe bars. First, use a color probe to select the color to be replaced on the image, and then adjust the allowed value within the range of fuzziness. The larger the value, the larger the selected color range, otherwise, the smaller the value is. If you want to select or subtract the color range, use the corresponding bar and bar, and then set hue and saturation in the transform column) and lightness (brightness), which can replace colors in the selected range.

If you need to adjust the contrast of an image, you can use the Auto Contrast (automatic contrast) function. At this time, Photoshop will automatically deepen the black and white of the darker part of the image, in this way, the image contrast can be easily enhanced.

The color of the image is disordered. You can adjust the color balance by using the color balance command. The image can be converted to the corresponding color by dragging the slider. The adjustment function is not described too much. Remember, you can select preserve luminosity to maintain the intermediate color of the image.

Gradient Map is a new color adjustment instruction of Photoshop 6.0. If you want to make a gradient color effect map, find it. It is absolutely correct. In the dialog box, dither (trembling color) can produce a smooth gradient, and the surface reverse (reverse) function can reverse the gradient.

The other color adjustment commands are similar, and there is no skill at all. You can naturally understand them when you are familiar with them. So I will not introduce it. For more information, see other articles. However, I do not recommend that you use the color Adjustment Command. Why? Because it has gradually been replaced by more powerful adjustment layers. This section describes how to adjust a layer. Here is the color chapter.