Fig. 5From: Design of image barcodes for future mobile advertisingIllustration of a reference map. a The input contone image. b The corresponding reference map obtained by using the screen in Fig. 4 a; each unit of the reference map represents a 4×4 cell. The green, red, and black units represent the shadow embeddable, highlight embeddable, and non-embeddable cells, respectivelyBack to article page