1. A method comprising: receiving, at an image processing device, image data corresponding to an image; determining object quality values based on a portion of the image data, the portion corresponding to an object represented in the image; accessing object category metrics associated with an object category corresponding to the object; and generating a notification indicating that the image data has been altered in response to a result of a comparison of the object quality values to the object category metrics, the result indicating alteration of the portion of the image data.