ROTATION and MIRRORING

Image rotation in multiples of 90º can be done on any image type (bitonal, grayscale or color).

The method ImGearRecImage.Orient Method immediately rotates and/or mirrors a whole single image in the recognition engine's memory space. Seven combinations of rotation and mirroring are available. This function ignores the image rotation mode setting of the recognition engine. The transformed image replaces the original image, keeping its type and format. It remains in the recognition engine's memory space, but is available to the application.

A rotation mode setting is made with OrientationMode, taking values from ImGearRecOrientationMode. These are:

AUTO : Automatic image orientation
NO : Do not orient the image
RIGHT : Rotate image to the right (90 degrees clockwise)
DOWN : Rotate image down (rotate twice)
LEFT : Rotate image to the left (90 degrees counter-clockwise)
FLIPPED : Flip around the Y axis
RIGHT_FLIPPED : Flip around the Y axis, then rotate to the right
DOWN_FLIPPED : Flip around X-axis
LEFT_FLIPPED : Flip around the Y axis, then rotate to the left

This mode-induced rotation is performed whenever ImGearRecImage.Preprocess Method is called. When a fixed value is given (e.g., LEFT), the original image is rotated.

When AUTO is set, grayscale or color images undergo an implicit secondary conversion to create a clean bitonal image. If AUTO is set and despeckle mode is ON for a bitonal image with over 280 dpi, a despeckled bitonal image is created. Orientation detection is done on the bitonal image - the despeckled image, if available. This bitonal image is not available to the application. The required rotation is performed on the original image. In both cases, the original rotated image remains in the recognition engine's memory space and is available to the application.