Adobe 13101332 User Guide - Page 330

Adobe Photoshop Help Using Help | Contents | Index Applying Filters for Special Effects Back 330 Ripple Creates an undulating pattern on a selection, like ripples on the surface of a pond. For greater control, use the Wave filter. Options include the amount and size of ripples. Shear Distorts an image along a curve. Specify the curve by dragging the line in the box to form a curve for the distortion.You can adjust any point along the curve. Click Default to return the curve to a straight line. In addition, you choose how to treat undistorted areas. (See "Defining undistorted areas" on page 323.) Spherize Gives objects a 3D effect by wrapping a selection around a spherical shape, distorting the image and stretching it to fit the selected curve. Twirl Rotates a selection more sharply in the center than at the edges. Specifying an angle produces a twirl pattern. Wave Works in a similar way to the Ripple filter, but with greater control. Options include the number of wave generators, the wavelength (distance from one wave crest to the next), the height of the wave, and the wave type: Sine (rolling), Triangle, or Square. The Randomize option applies random values.You can also define undistorted areas. (See "Defining undistorted areas" on page 323.) To replicate wave results on other selections, click Randomize, set the Number of Generators to 1, and set the minimum and maximum Wavelength and Amplitude parameters to the same value. ZigZag Distorts a selection radially, depending on the radius of the pixels in your selection. The Ridges option sets the number of direction reversals of the zigzag from the center of the selection to its edge. You also choose how to displace the pixels: Pond Ripples displaces pixels to the upper left or lower right, Out From Center displaces pixels toward or away from the center of the selection, and Around Center rotates pixels around the center. Noise filters (Photoshop) The Noise filters add or remove noise, or pixels with randomly distributed color levels. This helps to blend a selection into the surrounding pixels. Noise filters can create unusual textures or remove problem areas, such as dust and scratches, from an image. Add Noise Applies random pixels to an image, simulating the effect of shooting pictures on high-speed film. The Add Noise filter can also be used to reduce banding in feathered selections or graduated fills or to give a more realistic look to heavily retouched areas. Options include noise distribution: Uniform distributes color values of noise using random numbers between 0 and plus or minus the specified value for a subtle effect; Gaussian distributes color values of noise along a bell-shaped curve for a speckled effect. The Monochromatic option applies the filter to only the tonal elements in the image without changing the colors. Despeckle Detects the edges in an image (areas where significant color changes occur) and blurs all of the selection except those edges. This blur-ring removes noise while preserving detail. Dust & Scratches Reduces noise by changing dissimilar pixels.To achieve a balance between sharpening the image and hiding defects, try various combinations of radius and threshold settings. Or apply the filter on selected areas in the image. Using Help | Contents | Index Back 330