Graphics Programs Reference
In-Depth Information
(grays). You just drag them to make changes to the color levels in your photo, as shown in
Figure 7-13. To use the Levels input sliders, simply drag the left and right sliders from the ends of
the track until they're under the outer edges of the color data in the graph. The red arrows in this
figure show where you'd position the left and right sliders for this particular photo, respectively. If
there's empty space on the end of the graph (as there is here), just move the slider until it's under
the first mound of data.
When you move the left input slider, you tell Levels, “Take all the pixels from this point
down and consider them black.” With the right slider, you're saying, “Make this pixel and all
higher values white.” The middle slider adjusts the brightness values that are considered me-
dium gray. All three adjustments improve the contrast of your image.
