The purpose of this program is to demonstrate how to
zoom an image "in place" and how to window and level
(set "contrast and brightness") an image using object
graphics functionality. The exercise involves using
multiple views in an object graphics scene, and being
able to interact with different views in different ways.
FANNING SOFTWARE CONSULTING
David Fanning, Ph.D.
1645 Sheely Drive
Fort Collins, CO 80526 USA
Coyote's Guide to IDL Programming: http://www.idlcoyote.com
Widgets, Object Graphics.
None. The image "mr_knee.dcm" from the examples/data directory
is used if no data is supplied in call.
image: A 2D image array of any data type.
OPTIONAL KEYWORD PARAMETERS:
COLORTABLE: The number of a color table to use as the image palette.
Color table 0 (grayscale) is used as a default.
GROUP_LEADER: The group leader for this program. When the group leader
is destroyed, this program will be destroyed.
None. The Coyote Library program VCOLORBAR is included.
To use this program with your 8-bit image data and a red-temperature
color scale, type:
IDL> ContrastZoom, image, Colortable=3
The left image is used to "zoom" into a portion of the image.
The aspect ratio of the sub-image is always preserved. To see
the entire image, click and release the mouse button in this
The center image is used to adjust the contrast and brightness
(sometimes called the "window" and "level" of the image. Click and
drag the mouse vertically to set contrast. Click and drag the mouse
horizontally to set brightness. To return to original values (25%
contrast and 75% brightness), click and release in the center image.
The color bars shows the image values of the image.
Written by David Fanning, 18 November 2001.
Added second colorbar to show the relationship of the clamped
colors to the overall image values. 19 November 2001. DWF.