- 标题
- 摘要
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- 实验方案
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LSBs-based quantum color images watermarking algorithm in edge region
摘要： Based on the NEQR representation for quantum color and binary images, an enhanced quantum watermarking scheme is investigated through Gray code transform and least significant bit (LSB) steganography, which embeds a quantum binary image (i.e., watermark image) into the edge region of a quantum color image (i.e., carrier image) LSB and second LSB. The size of the carrier and watermark images are assumed to be 2n × 2n and 2n?1 × 2n?1, respectively. At first, the watermark image is resized into an appropriate size image with 4-qubit grayscale based on the nearest neighbor interpolation method, which is of the same size with the preselected edge region in carrier image. To enhance the security of the watermark image, the binary code of 4-qubit grayscale of watermark image is transformed into the corresponding Gray code, and one 3-Controlled-NOT gate is utilized to generate a quantum binary image |K 1(cid:2). To further scatter the watermark image qubits that are embedded into the LSB and second LSB of carrier image, the quantum image |K 1(cid:2) is employed to choose any two channels from the color image among the three channels of R, G and B (i.e., R, G or R, B channels would be chosen as the embedding channels). Furthermore, a quantum binary image |K 2(cid:2) is generated through XOR operation decided by the quantum image |K 1(cid:2), which is used to determine the embedding order of watermark image qubits. The extraction process is the inverse operation of embedding, which also needs the two quantum binary key images |K 1(cid:2) and |K 2(cid:2). Finally, the experiment results are simulated under the classical computer software MATLAB 2016(b), which illustrates that our investigated LSBs-based quantum watermarking has a better visual effect than some related works in terms of PSNR value.
关键词： Nearest neighbor interpolation,Gray code transform,Quantum watermarking,Least significant bit
更新于2025-09-23 15:21:21
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[IEEE OCEANS 2018 MTS/IEEE Charleston - Charleston, SC, USA (2018.10.22-2018.10.25)] OCEANS 2018 MTS/IEEE Charleston - High-resolution structured light D sensor for autonomous underwater inspection
摘要： Sensors that can provide detailed 3D data underwater are a prerequisite for enabling autonomous inspection of e.g. seafloor integrity, ocean habitats and subsea installations with unmanned underwater vehicles. Sonars are currently the primary source of 3D data on moving platforms subsea but have limited depth and lateral resolution. Several optical approaches exist such as passive stereo, which have problems with textureless objects, and LIDARs which are slow and provide low lateral resolution. In this work we explore the use of structured light, to achieve high-resolution 3D of objects in an underwater environment. We have adapted a Gray Code Phase Stepping (GCPS) structured light approach to be more robust to the contrast degradation caused by the scattering and attenuation of light in water. The robustness towards increasing water turbidity has been verified in pool experiments. We achieve a depth resolution ranging from 1.4mm to 6.4mm depending on the turbidity when imaging an object at 1.1m distance with a pixel resolution of 1280x1024 at a framerate of 8Hz.
关键词： underwater,turbidity,Gray code,Structured light,3D
更新于2025-09-19 17:15:36
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Camera Calibration Using Gray Code
摘要： In order to determine camera parameters, a calibration procedure involving the camera recordings of a checkerboard is usually performed. In this paper, we propose an alternative approach that uses Gray-code patterns displayed on an LCD screen. Gray-code patterns allow us to decode 3D location information of points of the LCD screen at every pixel in the camera image. This is in contrast to checkerboard patterns where the number of corresponding locations is limited to the number of checkerboard corners. We show that, for the case of a UEye CMOS camera, the precision of focal-length estimation is 1.5 times more precise than when using a standard calibration with a checkerboard pattern.
关键词： checkerboard,Gray code,camera calibration
更新于2025-09-19 17:15:36
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All-optical OR/XOR logic gate using PhC-based T-shaped waveguide with high-contrast output to implement 3-bit binary to gray code converter
摘要： In this article, a theoretical analysis on T-shaped waveguide is performed using coupled mode theory which admits its operation as power combiner, splitter and diverter. These applications of the waveguide can very well be utilized to project it as OR and XOR logic gates. In order to achieve this, the T-shaped waveguide is mapped onto the photonic crystal of square-type lattice and the validity is observed with the theoretical analysis. Later, the designed T-shaped waveguide is used to define OR and XOR gates, which results in the contrast ratio and response time of 54.43 dB and < 1 ps, respectively, at 1550 nm. Further, the higher contrast ratio of the T-shaped waveguide-based XOR logic gate allows it to cascade with itself in a single stage to realize a 3-bit binary to gray code converter. The simulation results show that the code converter operates with contrast ratio of above 9.82 dB at the output ports. Finally, the fair results obtained from theoretical analysis and numerical simulation conclude that the T-shaped waveguide can be a potential component as logic gate in the future photonic integrated circuits.
关键词： Photonic crystals,Binary to gray code converter,Optical computing,T-shaped waveguide
更新于2025-09-16 10:30:52