Change Raster Image Brightness, Contrast and Fade
For easier viewing or special effects, you can change several display properties of raster images in a drawing.
You can adjust brightness, contrast and fade for the display of an image as well as for the plotted output. To darken or lighten an image, you can adjust the brightness. To make poor-quality images easier to read, you can adjust the contrast. To make drawing geometry easier to see over images, you can adjust fade.