Filter\Pixelate\Color Halftone
Color Halftone
Simulates the effect of using an enlarged halftone screen on each channel of the image. For each channel, the filter divides the image into rectangles and replaces each rectangle with a circle. The circle size is proportional to the brightness of the rectangle.
To use the Color Halftone filter:
Choose Filter > Pixelate > Color Halftone.
Enter a value in pixels for the maximum radius of a halftone dot, from 4 to 127.
Enter a screen-angle value (the angle of the dot from the true horizontal) for one or more channels:
For Grayscale images use only channel 1.
For RGB images, use channels 1, 2, and 3, which correspond to the red, green, and blue channels.
For CMYK images, use all four channels, which correspond to the cyan, magenta, yellow, and black channels.
Click Defaults to return all the screen angles to their default values.
Click OK.