![]() Whenever an image's color depth is reduced to 8-bits per pixel or less, a dithering method may come into play. Then, if necessary, you can reduce the color resolution of the combined image. The simplest solution is to convert both images to 24-bits per pixel before combining them. To combine two images, they must have the same color resolution, and if they are less than 16-bits per pixel, they must use the same palette. Suppose you want to combine one 8-bit image with another one. If the new file format does not support the original color resolution, you can specify a different color resolution when you save the image. Suppose you want to save an image in a different file format. Of course, there would be some loss of quality on a 24-bit display device, and the loss would be permanent if you then saved the image in the same file. Then, if you were using an 8-bit display device, you would not see any difference in the quality of the image. You can conserve memory by loading it as an 8-bit image. Suppose you need to load a large 24-bit image on a computer that does not have much memory. Nevertheless, in some cases you may need to increase or decrease the color resolution. Therefore, in most cases you can load, display, modify and save an image without ever changing its color resolution. LEADTOOLS lets you manipulate an image and display it on any Windows-compatible device, regardless of the image's color resolution. There are many possibilities, ranging from two colors to 16 million. If it is loaded from a GIF file, it is likely to have 256 colors. If it is loaded from a color scanner or a JPEG file, it can have 16 million colors. If an image in your computer is loaded from a FAX scanner or received as a FAX transmission, it is a black-and-white (1-bit) image. For more information, see Adobe Photoshop 7.0 online Help.Color resolution (also called color depth) refers to the number of possible colors in an image, as determined by the bits-per-pixel. This remapping reassigns all the pixels that appeared in the selected color to the new color or transparency. Note: In Photoshop 7.0 and ImageReady 7.0, you can also quickly map one color to another color or to a transparency. The swatch changes position in the palette and a small diamond appears in the center of the swatch, indicating that it has been shifted to its nearest Web-palette equivalent.īy Web-shifting the brown background, you change its color to one that can be displayed without dithering by a Web browser on a 256-color system. The sampled color appears selected in the Color Table palette.ģ Click the Web-shift button () at the bottom of the Color Table palette. You can toggle the browser dither preview off and on by pressing Ctrl+Shift+Y (Windows) or Command+Shift+Y (Mac OS).Ģ Select the eyedropper tool (/ ) and click anywhere in the dithered brown background. Note: If you don't see the dithering, increase the zoom to about 300% or turn off the browser dither preview and then turn it back on to observe the effects. ![]() You'll Web-shift that color to reduce the amount of browser dither in the image. Notice that browser dither occurs in the brown African Savannah background. Because the Web palette includes the subset of colors that appear in both the Windows and the Mac OS system palettes, Web palette colors will display without dithering in browsers on either platform.ġ With the optimized 14Start2.psd image open, choose View > Preview > Browser Dither (so that a checkmark appears next to the command). ![]() To protect a color from browser dither, you can Web-shift the color, converting the color to its nearest equivalent in the Web palette. From ImageReady, you can preview how an optimized image will look when dithered in a Web browser. ![]() As you learned earlier, images that include non- Web-safe colors undergo a process of dithering when displayed in a Web browser using an 8-bit display, because the browser simulates colors that do not occur in the 8-bit system palette. ![]()
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