Abstract: High dynamic range (HDR) imaging, aiming to increase the dynamic range of an image by merging multiexposure images, has attracted much attention. Ghosts are often observed in a resultant image, due to camera motion and object motion in the scene. Low-rank matrix completion (LRMC) provides an effective tool to remove ghosts. However, user specification of the included or excluded regions is required. In this paper, we propose a novel HDR imaging method based on bidirectional structural similarities and weighted low-rank matrix completion. In our method, we first propose the bidirectional structural similarities containing forward-projection structural similarity (FPSS) and backward-projection structural similarity (BPSS) to divide each image into four groups: motion region, saturated region in the source image, saturated region in the reference image, and static and unsaturated regions. Then, the weight maps and the motion maps constructed based on FPSS and BPSS are introduced in the weighted LRMC model to reconstruct the background irradiance maps. Experiments are conducted on several challenging image sets with complex scene, and the results show that the proposed method outperforms three current state-of-the-art methods and Photoshop cs6 and is robust to the reference image. PubDate: Thu, 26 Dec 2019 10:20:03 +000
Abstract: This paper proposes a method of encrypting images with password protection for secure sharing based on deoxyribonucleic acid (DNA) sequence operations and the tangent-delay ellipse reflecting the cavity-map system (TD-ERCS). The initial values of the TD-ERCS system are generated from a user’s password, and the TD-ERCS system is used to scramble the pixel locations of the R, G, and B matrices of the original image. Next, three DNA-sequence matrices are generated by encoding the permuted color image such that it can be transformed into three matrices. Then, the TD-ERCS system is employed to generate three chaotic sequences before encoding the DNA into the three matrices. Thereafter, a DNA exclusive OR (XOR) operation is executed between the DNA sequences of the permuted image and the DNA sequences generated by the TD-ERCS system to produce three encrypted scrambled matrices. Finally, the matrices of the DNA sequences are decoded, and the R, G, and B channels are recombined to form an encrypted color image. The results of simulation and security tests reveal that the proposed algorithm offers robust encryption and demonstrates the ability to resist exhaustive, statistical, and differential attacks. PubDate: Mon, 25 Nov 2019 03:05:13 +000
Abstract: Merge mode can achieve a considerable coding gain because of reducing the cost of coding motion information in video codecs. However, the simple adoption of the motion information from the neighbouring blocks may not achieve the optimal performance as the motion correlation between the pixels and the neighbouring block decreases with their distance increasing. To address this problem, the paper proposes a Euclidean distance-based weighted prediction algorithm as an additional candidate in the merge mode. First, several predicted blocks are generated by motion compensation prediction (MCP) with the motion information from available neighbouring blocks. Second, an additional predicted block is generated by a weighted average of the predicted blocks above, where the weighted coefficient is related to Euclidean distances from the neighbouring candidate to the pixel points in the current block. Finally, the best merge mode is selected by the rate distortion optimization (RDO) among the original merge candidates and the additional candidate. Experimental results show that, on the joint exploration test model 7.0 (JEM 7.0), the proposed algorithm achieves better coding performance than the original merge mode under all configurations including random access (RA), low delay B (LDB), and low delay P (LDP), with a slight coding complexity increase. Especially for the LDP configuration, the proposed method achieves 1.50% bitrate saving on average. PubDate: Sun, 22 Sep 2019 00:06:31 +000
Abstract: Traditional museums and most digital museums use window display to exhibit their collections. However, the agricultural tools are distinctive for their use value and wisdom contained. Therefore, this paper first proposes a method of virtual interactive display for agricultural tools based on virtual reality technology, which combines static display and dynamic use of agricultural tools vividly showing the agricultural tools. To address the problems of rigid interaction and terrible experience in the process of human-computer interaction, four human-computer interaction technologies are proposed to design and construct a more humanized system including intelligent scenes switching technology, multichannel introduction technology, interactive virtual roaming technology, and task-based interactive technology. The evaluation results demonstrate that the system proposed achieves good performance in fluency, instructiveness, amusement, and practicability. This human-computer interaction system can not only show the wisdom of Chinese traditional agricultural tools to the experiencer all over the world but also put forward a new method of digital museum design. PubDate: Tue, 01 Jan 2019 00:00:00 +000
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