Optimization options for WBMP format

WBMP format is the standard format for optimizing images for mobile devices, such as cell phones. WBMP supports 1-bit color, which means that WBMP images contain only black and white pixels.

Choose an option from the Dither Algorithm menu to determine the method for converting pixel values to black or white:

• No Dither applies no dither to the image.
• Diffusion applies a random pattern that is usually less noticeable than Pattern dither. The dither effects are diffused across adjacent pixels. If you select this algorithm, specify a Dither percentage to control the amount of dithering that is applied to the image. You can use masks from type layers, shape layers, and alpha channels to vary the Dither percentage across an image. This technique produces higher-quality results in critical image areas without sacrificing file size. (See Using weighted optimization.)

Note: Diffusion dither may cause detectable seams to appear across slice boundaries. Linking slices diffuses the dither pattern across all linked slices, and eliminates the seams.

• Pattern applies a halftone-like square pattern to determine the value of pixels.
• Noise applies a random pattern similar to the Diffusion dithering, but without diffusing the pattern across adjacent pixels. No seams appear with the Noise algorithm.