Image Properties

Bitmap Colors and Resolution. The quality and clarity of a bitmap is controlled by the number of colors and resolution. The number of colors and resolution depends on the way the bitmap was created. For example, if you scan a topographic map, the resolution is controlled by the capabilities and settings of the scanner.

Once a bitmap has been created, the resolution and number of colors are pretty much fixed. For example, if you have a 256-color bitmap, it is difficult to increase the number of colors without rescanning. Generally speaking, more colors and higher resolution mean clearer pictures. However, higher resolution images require more memory and take more time to display.

Video Cards. Video cards also have a limited number of colors and resolution. If you try to display a bitmap with a large number of colors on video card with fewer colors, some colors maybe faded, splotchy or distorted. You can generally fix this type of problem by switching to a higher resolution video mode.

Printing Bitmaps. Once you have plotted a cave on top of the bitmap, you may want to print the bitmap. The quality of the print will depend on the type of printer you are using and the type of bitmap image you are using. Generally, black and white printers work best with black and white bitmaps. Color inkjet printers work very well with color bitmaps.