Brightness and Contrast
The Brightness and Contrast live effect lets you change the tonal values of an image or object through three parameters:
- Brightness The Brightness control makes every color or tone lighter or darker by an absolute value. If you increase brightness, very light colors will become "blown out" to white. If you decrease brightness, colors in the shadows will become fully black.
- Contrast The Contrast control alters the distinctions between light and dark areas. If you increase contrast, details might become more obvious, but highlights (light colors) tend to "blow out" to white and shadows tend to fill in and become black. If you decrease contrast, the lightest and darkest areas stay about the same, but everything else becomes flat and washed out.
- Gamma The Gamma control adjusts the midpoint of the tonal scale and leaves the white and black points as is. This is often the most beneficial when working with scanned images because you can increase contrast and brightness without damaging highlights and shadows. Increasing gamma (dragging the slider to the left) darkens the image; decreasing gamma lightens the image.
Applying Brightness and Contrast to three
objects:
a bitmapped image, a rectangle with a gradient, and a
text object.
The original objects (above)
and the affected objects (below).
You can also adjust image contrast using the Auto Contrast effect.
For more information about how to apply live effects, see Live effects.