Adobe 13101332 User Guide - Page 337

Adobe Photoshop Help Using Help | Contents | Index Applying Filters for Special Effects Back 337 3 Select a text box representing an adjacent pixel. Enter the value by which you want the pixel in this position multiplied. 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. 4 Repeat steps 2 and 3 for all pixels to include in the operation.You don't have to enter values in all the text boxes. 5 For Scale, enter the value by which to divide the sum of the brightness values of the pixels included in the calculation. 6 For Offset, enter the value to be added to the result of the scale calculation. 7 Click OK.The custom filter is applied to each pixel in the image, one at a time. Use the Save and Load buttons to save and reuse custom filters. High Pass (Photoshop) Retains edge details in the specified radius where sharp color transitions occur and suppresses the rest of the image. (A radius of 0.1 pixel keeps only edge pixels.) The filter removes low-frequency detail in an image and has an effect opposite to that of the Gaussian Blur filter. It is helpful to apply the High Pass filter to a continuous-tone image before using the Threshold command or converting the image to Bitmap mode. The filter is useful for extracting line art and large black-and-white areas from scanned images. Minimum and Maximum (Photoshop) Are useful for modifying masks.The Minimum filter has the effect of applying a spread-spreading out black areas and shrinking white areas. The Maximum filter has the effect of applying a choke-spreading out white areas and choking in black areas. As does the Median filter, the Maximum and Minimum filters look at individual pixels in a selection. Within a specified radius, the Maximum and Minimum filters replace the current pixel's brightness value with the greatest or least brightness value of the surrounding pixels. Offset Moves a selection a specified horizontal or vertical amount, leaving an empty space at the selection's original location. You can fill the empty area with the current background color, with another part of the image, or with your choice of fill if the selection is near the edge of an image. (See "Defining undistorted areas" on page 323.) Tile Maker (ImageReady) Enables you to prepare an image for use as a tiled background. You can blend the edges of an image to create a seamless background. You can also create a kaleidoscopic background in which an image is flipped horizontally and vertically to create an abstract design. Digimarc filters The Digimarc filters embed a digital watermark into an image to store copyright information. For more information, see "Adding digital copyright information" on page 460. Lighting Effects filter The Lighting Effects filter lets you produce myriad lighting effects on RGB images. You can also use textures from grayscale files (called bump maps) to produce 3D-like effects and save your own styles for use in other images. Note: The Lighting Effects filter works only on RGB images. Using Help | Contents | Index Back 337