Adjusting Images with the Histogram

You can use the Histogram to adjust the brightness and contrast of an image, to maximize detail, to convert color or grayscale images to bitonal, and to convert color images to grayscale.

The Histogram changes the image data definition, so all future insertions of the image include these changes. If you want to just change brightness and contrast of a particular insertion, you can change the color map. For more information, see Changing the Color Map of an Image.

You can adjust a whole image or a sub-region. You can define a sub-region using one of four methods:

• Use an existing closed vector entity to define the sub-region.
• Use an existing image clip.
• Define a rectangular sub-region by clicking two-points.
• Define a polygonal sub-region by clicking several points.