Create Bitmap Copy - Palette Options

Dithering

Dimmed for True Color.

You can select between three types of dithering with these options. Choosing None means there will be no dithering, Ordered using an ordered (regular) dithering pattern and Error diffusion uses error-diffused dithering (a more complex dithering technique). In general, error diffusion will give the best results, but only use dithering when really necessary as it prevents the file compression working so well and so makes files larger. You cannot use Ordered dithering with an optimized palette.

Note that you can set the dithering type for the screen display too, see Changing the screen dithering.

Palette

Dimmed for True Color.

Choose between browser palette, WebSnap palette and optimized palette

Color Depth

Choose the number of colors your bitmap requires. The more colors, the larger the bitmap file.

Transparent bitmaps with 256 colors or less use one of the colors for the transparency. This means a 2 color transparent bitmap has one color plus transparency.

Max colors

Dimmed for True Color.

With this field, you can specify how many colors in the palette of the bitmap are actually used. This means you can create, for example, an 256 color bitmap where only 100 of the 256 palette entries are used. With some experimentation you can alter this setting to create bitmaps that are very small by reducing the number of colors until the quality is just at the level you will accept.

Palette colors

(Up to 256 colors only)

This displays the range of colors in the current palette. You can edit any of the colors if you want extra control - see Editing colors in the create bitmap palette.

To check where colors are used in the bitmap, select the Color Selector button. Then, as you move over the image image in the Preview window, the color under the pointer is highlighted in the palette.

Small squares on the colors give you extra information about the color:

in the center - web safe

top left - transparent

bottom left - locked color

bottom right - edited color

(hatched square) deleted color.

Buttons

Dimmed for True Color.

These buttons (except Transparent background) apply to the selected color: click on a color in the palette (above the buttons) to select it. You can also select these options by right-clicking on a color, then selecting from the pop-up menu.

(Lock): always include this color in the palette. This is useful if you are reducing the number of colors in the palette. For more information see Locking a color.

(Web-safe); snap this color to the nearest color in the 216-color Netscape Navigator and Microsoft Internet Explorer palette. For more information see Making a color web-safe.

(Transparent background): make transparent any areas not covered by the selected objects. Selecting this option automatically makes one entry in the palette transparent. Note to CorelXARA users: this replaces Transparent on the Options tab in CorelXARA.

(Transparent): make this color entry transparent. Note the difference between this option which makes parts of the selected objects transparent and Transparent background which makes transparent those areas behind the selected objects. For more information see Making a color transparent.

(Delete): delete this color from the palette. Any areas in the bitmap that use the deleted color then use the nearest color in the palette. The fewer colors in the palette the smaller the bitmap file. Click R to undo a delete. For more information see Deleting a color.

(Restore): undelete this color.

(Add system colors): adds 28 colors to the palette. These colors are the regular Windows system colors and a number of primary colors. This ensures the palette includes a spread of colors and may improve the quality of the image, particularly if it contains a wide range of colors. You may need to experiment with this option to get the best results.

Sort By:

Controls the order in which colors are displayed in the palette. This option applies only to the display in this dialog box. It has no effect on the bitmap nor on the actual colors. Options:

Number of uses - arranged by the area each color covers.

Luminance - arranged by the RGB brightness of the colors.

Hue - arranged by hue.