Orion 52083 - Manual (Page 13)

13
When an image is displayed, you will notice a graph in the Screen Stretch
Window. This is called the “histogram” of the currently displayed image (Figure
10). A histogram is a simple bar graph that shows the range of brightness in
an image. Each bar in the graph represents a level of brightness; the bar to
the far left in the histogram represents the dimmest pixels, and the bar to the
far right is for the brightest pixels. The height of the bar is the total number of
pixels at that brightness level in the image. Every image has a different histo-
gram depending on how much of the image is bright or dark. Directly viewing
the histogram of your image in the Screen Stretch Window provides an easy
interface for making decisions on how the screen stretch should be set.
In Maxim DL Essentials, the two parameters entered in the Screen Stretch
Window are Minimum and Maximum. A pixel that is at the Minimum value
is set to zero (black), and a pixel at the Maximum value is set to 255 (white).
An easy way to adjust the Maximum and Minimum values is to move the
slider arrows located directly under the histogram of the image in the Screen
Figure 9. The settings in the Screen Stretch Window greatly determine how an
image will appear on your computer screen.
Figure 10. A histogram is a visual
representation of the range and levels
of brightness in an image.
Number
of
pixels
at
brightness
level
Range of brightness levels