1. A non-transitory machine readable storage medium storing instructions which when executed by a processing system cause the processing system to perform operations, the operations comprising: storing object detection metadata that provides a location of a detected object in image data, wherein the location is specified in a pixel-independent coordinate system and an aspect ratio of dimensions of the pixel-independent coordinate system matches an aspect ratio of pixel dimensions of the image data; and storing object identification metadata that specifies an identity of the detected object.