Generating visually appealing QR codes using colour image embedding

Quick Response (QR) codes have become very popular in current scenario. Being machine readable, they appear like blocks of random black and white noise. With their increasing use in marketing material, many attempts have been made to make them visually appealing by embedding images and logos. We propose a colour image embedding method that uses circular modules to reduce the block-like appearance of the code. The luminance of the image pixels corresponding to the centric and surrounding regions of a circular code module is modified in such a way that they blend into the code with least visual distortion, and the resultant code demonstrates high degree of decoding robustness. The results of experiments to assess the visual appeal of the resultant codes, and their tolerance to noise and blur indicate that the visually appealing codes have decodability comparable to the original QR codes, thus justifying the attempt to embed image in an otherwise non-appealing QR code. The codes generated by the proposed method and three other state-of-the art methods are compared for visual appeal and decoding robustness. The results of the comparison indicate that the codes generated by the proposed method have visual appeal best amongst the codes generated by other state-of-the art methods. In terms of tolerance to noise and blur, they are the best amongst the codes which have comparable visual appeal, and second best amongst all.