Image Orientation

ImageGear uses two different places to store an image's orientation information: Orientation attribute of HIGEAR, and Orientation attribute of display settings.

When ImageGear loads an image, and the image’s file format supports storing the Orientation attribute (e.g., TIFF format), ImageGear stores this attribute in HIGEAR. You can get or modify this attribute with IG_image_orientation_get and IG_image_orientation_set, correspondingly.

If the application displays the image, ImageGear copies HIGEAR’s Orientation attribute to the image’s Display settings. This allows ImageGear to display the image using the orientation specified in the source file. You can get or set display orientation using IG_dspl_orientation_get and IG_dspl_orientation_set, correspondingly. Changing the display orientation does not change the HIGEAR Orientation attribute. Changing the HIGEAR Orientation attribute does not change the display orientation.

When saving an image to a format that supports orientation, ImageGear saves the HIGEAR’s Orientation attribute to the file’s header, and does not take the display orientation into account. If you’d like to save an image using the current display orientation, copy the orientation from the display settings to HIGEAR.