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Intensity
The Intensity graph displays the intensity (on the vertical-axis) of each of the selected pixels (horizontal-axis). Right-click on the graph for more options. To save the intensity data to a file (tab-separated text) right-click on the graph and select Save Graph Data As.... The Intensity graph only works when you use the Mouse Selection tool to select a Row, Column or Rectangle (for use with diagonal measurement).
The X-axis represents the actual pixel being measured. Row and Column Means require a Rectangle (or Off to use the entire image as the Rectangle).
Histogram
The Histogram collects the total amount of pixels (vertical-axis) for each of the possible intensity values (horizontal-axis) for each of the color channels. The histogram is taken over the currently selected area and works best for a small rectangular selection(See 4.4).
Right-click on the graph for more options. To save the histogram data to a file (tab-separated text) right-click on the graph and select Save Graph Data As....
When the histogram is being displayed, if you right-click on the graph and select Show Control Window the following Analysis Graph Controls are available.
By default the histogram data is displayed in Combined RGB mode. The Analysis Graph Controls can be used to display a luminance graph as well. When displaying a luminance graph the user has the option to display additional data characteristics.
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