5.5.4.3 ProcessOrient

 
This module changes the orientation of StereoImages.

The main parameters are -left, -right and -both, each is followed by an orientation. The orientation following -left is used on the left component of the StereoImages, that following -right is used on the right components and that following -both is used on both components. If -left, -right and -both are all omitted, the default is -both.

Valid orientations are:

• hflip for a horizontal flip
• vflip for a vertical flip
• rot180 or 180 for a rotation about 180 degrees (equivalent to both a horizontal flip and vertical flip, in either order)
• rot90cw, 90cw or cw for a 90 degree clockwise rotation
• rot90ccw, 90ccw or ccw for a 90 degree counter-clockwise rotation

The module works by utilising the ImageVision iflOrientation property of ilImage objects, which defines the coordinate space of the image. A change in coordinate space, without any change in image data, is equivalent to a change in orientation of the data. Since the image data itself is untouched by this operation it is a very fast operation, and operates when the ilImage's data is accessed in the new orientation (specifically, the data is looped in a different order, corresponding to the new orientation). The module uses a lookup table which maps operations and original image orientations onto the new image orientation, which is then set in the image before it is returned.

The 90 degree rotation orientations transpose the and dimensions of the image, but the other orientations do not alter the dimensions of the image.

The valid names for this module are orient and orientate.