Intensity Profiles

Jim can show a graph of vertical or horizontal intensity profiles through an image slice. To show intensity profiles, select Profiles from the View menu: . If you require oblique profiles, or profiles along curved paths, then please refer to the ROI section of this manual.

The Profile frame now pops up. Until you select a slice, the graph will be blank. With a slice selected, the graph shows a plot of image intensity along a horizontal or vertical line through the image.

To switch between horizontal and vertical profiles, click on the

and

buttons. To switch between position display in pixels and millimetres, use the units toggle button.

To change the location of the profile, simply click and/or drag the mouse over the selected image slice. The red/blue line shows the location of the profile.

As you move the mouse over graph in the Profile frame, the read-out at the bottom of the frame will show the location of the mouse pointer relative to the image slice, with the read out showing the row/column location in the image, the horizontal/vertical position within the row/column, and the intensity (I) at that position. A pair of cursors will mark the position and intensity at the cursor location:

In addition, the location of the mouse cursor in the graph will be shown on the image as a small cross:

To write the profile graph data to a file, choose Write from the File menu in the Profile frame:

The profile graph data is written in a tab-separated table with two columns: the first is the location (either in pixels or in mm, depending on the units setting) and the second is the pixel intensity. See also the File Formats section.

To export the profile graph to a PDF document, choose Export as PDF from the File menu in the Profile frame:

Profiles display is available for static image display and for movies. For movies, the profile is continuously updated as the movie steps through the frames. Click the button when you have finished with intensity profiles.

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