To produce their effects, some filters load and use other images, such as textures and displacement maps. These filters include the Conté Crayon, Displace, Glass, Lighting Effects, Rough Pastels, Texturizer, Underpainting, and Custom filters. Not all of these filters load images or textures in the same way.
All textures must be in the Photoshop format. Most filters use only the grayscale information of a color file.
The Rough Pastels, Underpainting, Glass, Conté Crayon, and Texturizer filters have texturizing options. These options make images appear as if they were painted onto textures such as canvas and brick, or viewed through surfaces such as glass blocks or frosted glass.
The Displace, Shear, and Wave filters in the Distort submenu and the Offset filter in the Other submenu let you treat areas undefined (or unprotected) by the filter in the following ways:
Fills the undefined space with content from the opposite edge of the image.
Repeat Edge Pixels
Extends the colors of pixels along the edge of the image in the direction specified. Banding may result if the edge pixels are different colors.
Set To Background (Offset filter only)
Fills the selected area with the current background color.
The Threshold value determines how dissimilar the pixels should be before they are eliminated.
The Threshold slider gives greater control for values between 0 and 128—the most common range for images—than for values between 128 and 255.
Increasing the radius blurs the image. Use the smallest value that eliminates the defects.
The Displace filter shifts a selection using a color value from the displacement map—0 is the maximum negative shift, 255 the maximum positive shift, and a gray value of 128 produces no displacement. If a map has one channel, the image shifts along a diagonal defined by the horizontal and vertical scale ratios. If the map has more than one channel, the first channel controls the horizontal displacement, and the second channel controls the vertical displacement.
The filter creates displacement maps using a flattened file saved in Adobe Photoshop format. (Bitmap mode images are unsupported.)
When the horizontal and vertical scale are set to 100%, the greatest displacement is 128 pixels (because middle gray produces no displacement).
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.
Blocks creates objects with a square front face and four side faces. To fill the front face of each block with the average color of the block, select Solid Front Faces. To fill the front face with the image, deselect Solid Front Faces.
Pyramids creates objects with four triangular sides that meet at a point.
Random to give each block or pyramid an arbitrary depth.
Level-based to make each object’s depth correspond to its brightness—bright protrudes more than dark.
Use the Info panel in Grayscale mode to identify a color value that you want traced. Then enter the value in the Level text box.
For example, to multiply the brightness value of the pixel to the immediate right of the current pixel by 2, enter 2 in the text box to the immediate right of the center text box.
Use the Save and Load buttons to save and reuse custom filters.