The DetectOrientation method of the FRPage object detects text orientation on the image. The method returns the TextOrientation object, if orientation has been detected successfully, and NULL, if the program failed to detect orientation. Please find more in Developer'sHelp → API Reference → Document-Related Objects → FRPage → DetectOrientation Method of the FRPage Object. The OrientationDetectionParams object provides access to the parameters of orientation detection. Please learn more from the Developer's Help → API Reference → Parameter Objects → Preprocessing, Analysis, Recognition, and Synthesis Parameters → OrientationDetectionParams Object section. You can also use the CorrectOrientation property of the PagePreprocessingParams object to correct page orientation automatically.
Skew can be corrected only for angles not greater than 20 degrees. By default, skew is corrected by horizontal and vertical text lines. Other types of skew correction should be used only in the cases they are intended for. See Developer's Help → API Reference → Enumerations → CorrectSkewModeEnum for details.
Rotation property of the PrepareImageMode object specifies the rotation angle to apply to the image during preparation. The default option specifies no rotation, other possible options specify clockwise, counterclockwise, and upside-down rotation. Kindly see Developer's Help → API Reference → Enumerations → RotationTypeEnum for details.