Data detection method from printed images with different resolutions using tablet device

In this paper, we propose a method of embedding and detecting data in printed images with several resolutions using the camera of a tablet device. The proposed method is based on a method that uses block division and code diffusion. To specify the resolution of an image and the number of blocks, invisible markers that are embedded in the amplitude domain of the discrete Fourier transform of the target image are used. The angles between the markers and the x-axis are used to specify the resolution and the number of blocks. The proposed method can increase the variety of images suitable for data embedding. From experimental results obtained using a tablet device, it is shown that the proposed method is effective for specifying the resolution and the number of blocks in a captured image.