1. An object recognition apparatus comprising: a memory configured to store at least one object-specific metric map that maps an image color space to a set of metric values related to a target object; and a processor coupled with the memory and configured to operate as a recognition engine by executing the steps of: obtaining the at least one object-specific metric map; obtaining a digital representation of a scene including image data; generating map-altered image data according to the object-specific metric map executed on the image data; deriving a metric-based descriptor set by executing an image analysis algorithm on the map-altered image data; and using the metric-based descriptor set to retrieve digital content, comprising one or more virtual reality objects, augmented reality objects, or mixed reality objects, associated with the target object, and wherein at least a portion of the digital content is superimposed over an image of a real-world object.