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vrotate.c File Reference

vrotate - rotate an image by an arbitrary angle. More...


Detailed Description

vrotate - rotate an image by an arbitrary angle.

Description
vrotate rotates an image by an arbitrary angle. vrotate rotates each input image by the specified angle, producing a file of output images. The rotation is done by first rotating the image by a multiple of 90 degrees (using flips and transpositions) to an angle nearest to the specified angle, and then by completing the rotation using Alan Paeth's three-shear method.
Because each pixel in the rotated image is a weighted average of the corresponding pixels in the original image, the set of colors (or gray shades) used by the origi­ nal image will not be preserved in the rotated image.
In general, the edges of the rotated image will not be parallel to the vertical and horizontal axes. In such cases, the output image will be the smallest rectangular region containing the whole rotated image. Portions of the output image not covered by the rotated image will be filled with zeros.
Usage
vrotate
Parameters:
-in  input image
-out  output image
-angle  Specifies the angle of rotation in degrees. Positive values rotate counterclockwise; negative ones rotate clockwise. Default: 90.
Examples

Known bugs
none.
Author:
Daniel Ko, UBC Laboratory for Computational Intelligence

Generated on Tue Nov 23 09:50:52 2004 for VIA - Volumetric Image Analysis by doxygen1.2.15