A system and method of obtaining an occlusion key using a background pixel map is disclosed. A target image containing a target location suitable for displaying a virtual augmentation is obtained. A stream of current images are transformed into a stationary stream having the camera pose of the target image. These are segmented using a trained neural network. The background pixel map is then the color values of background pixels found at each position within the target location. An occlusion key for a new current image is obtained by first transforming it to conform to the target image and then comparing each pixel in the target location with the color values of background pixels in the background pixel map. The occlusion key is then transformed back to conform to the current image and used for virtual augmentation of the current image.