Introduction of Photoshop pixel function

　　Filter (filter) is one of the features of Photoshop, with powerful features. The complex digital effect of filters is derived from photographic technology, which can not only improve the image's effect and conceal its defects, but also produce many special effects on the basis of the original image. filters mainly have the following characteristics:

1, filter can only be applied to the current visual layer, and can be applied repeatedly, continuous application. However, it can only be applied to one layer at a time.

2, filters can not be applied to bitmap mode, indexed colors and 48bit RGB mode of images, some filters only for RGB mode images, such as brush strokes filter and sketch filter can not be used in CMYK mode. Also, filters can only be applied to colored areas of a layer and have no effect on fully transparent areas.

3. Some filters are fully processed in memory, so the capacity of the memory has a significant effect on the speed at which the filter is generated.

4, some filters are very complex or to apply a filter image size is very large, it takes a long time to execute, if you want to end the filter effect is generated, just press the ESC key.

5. The last filter you used will appear at the top of the filter menu, and you can reapply the last used filter effect to the image by executing this command.

6, if the filter settings in the window to adjust the effect of their own feel dissatisfied, want to restore the parameters before adjustment, you can hold down the ALT key, then the cancellation button will become reset button, click this button can reset the parameters to the state before the adjustment.

Photoshop has a total of 17 sets of filters, which can be accessed via the Filter menu (Figure 1), and for the extraction, liquefaction, pattern generators, and DIGIMARC commands, we'll explain them later.

Figure 1

　　First group: pixelate (Pixel)

The Pixelate (pixel) filter divides the image into a certain area, transforms the area into the corresponding color block, and then the color blocks form an image, similar to the effect of color composition.

　　1, Facet ( color block filter )

　　role: use solid color or similar color of the pixel caking to redraw the image, similar to the effect of hand-painted.

　　Tuning Parameters: None

　　Graphic effect:

Color-block effect of original image

　　2, Color halftone (color halftone filter)

　　function: simulates the effect of using a halftone screen on each channel of an image, decomposes a channel into several rectangles, and replaces the rectangle with a circle, the size of which is proportional to the brightness of the rectangle.

　　Adjust parameters:

　　Maximum radius: Set the maximum radius of the halftone screen.

　　for grayscale images : Only channel 1 is used;

　　for RGB images : Using 1,2 and 3 channels, respectively, corresponding to red, green and blue channels;

　　for CMYK image : Use all four channels, corresponding to cyan, magenta, yellow and black channels.

　　Graphic effect:

Color halftone effect of original image

　　3, Pointillize (point shape)

　　function: the image is decomposed into a random distribution of dots, simulating the effect of dot-shaped painting. Fills a blank area between the dots using the background color.

　　Adjust parameters:

Cell Size: Resize the cell, do not set too large, otherwise the image will become unrecognizable, ranging from 3 to 300. Category:

• PS Filter Tutorial