- 标题
- 摘要
- 关键词
- 实验方案
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A novel image encryption method based on hyperchaotic system and pixel information association
摘要： In recent years, a variety of image encryption methods based on chaotic systems has been proposed, and has achieved good results. In order to improve the security of image encryption, this paper proposes a new image encryption method with a dynamic key, based on a hyperchaotic system and the association of pixel information, and designs the three-level encryption structure with diffusion encryption, scrambling encryption and re-diffusion encryption. The innovation of this method is to add the whole information of the image and the position information of the pixels in the diffusion encryption, and add the data information of the pixels in the scrambling encryption. The plaintext information of the image is added to the encryption process, which can enhance the security of encryption. Experiments demonstrate that the image encryption method proposed in this paper has the characteristics of strong sensitivity, low correlation between adjacent pixels, anti-differential attack and high security.
关键词： pixel information association.,image encryption,hyperchaotic system
更新于2025-09-04 15:30:14
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Optimization of CMOS Image Sensor Utilizing Variable Temporal Multi-Sampling Partial Transfer Technique to Achieve Full-frame High Dynamic Range with Superior Low Light and Stop Motion Capability
摘要： Differential Binary Pixel Technology is a threshold-based timing, readout and image reconstruction method that utilizes sub-frame partial charge transfer technique in a standard four-transistor (4T) pixel CMOS Image sensor (CIS) to achieve HDR video with Stop Motion. This technology improves low light signal-to-noise ratio (SNR) by up to 21dB. The method is verified in silicon using a TSMC 65nm 1.1μm pixel technology 1 megapixel (MP) test chip array and is compared with a traditional 4× oversampling technique using full charge transfer. The test chip is also compared with the iPhone 6s rear view camera to show superior HDR video capability.
关键词： HDR video,iPhone 6s,Differential Binary Pixel Technology,SNR,CMOS Image sensor,Stop Motion,TSMC 65nm
更新于2025-09-04 15:30:14
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Generating Continental Scale Pixel-Based Surface Reflectance Composites in Coastal Regions with the Use of a Multi-Resolution Tidal Model
摘要： Generating continental-scale pixel composites in dynamic coastal and estuarine environments presents a unique challenge, as the application of a temporal or seasonal approach to composite generation is confounded by tidal influences. We demonstrate how this can be resolved using an approach to compositing that provides robust composites of multi-type environments. In addition to the visual aesthetics of the images created, we demonstrate the utility of these composites for further interpretation and analysis. This is enabled by the manner in which our approach captures the spatial variation in tidal dynamics through the use of a Voronoi mesh, and preserves the band relationships within the modelled spectra at each pixel. Case studies are presented which include continental-scale mosaics of the Australian coastline at high and low tide, and tailored examples demonstrating the potential of the tidally constrained composites to address a range of coastal change detection and monitoring applications. We conclude with a discussion on the potential applications of the composite products and method in the coastal and marine environment, as well as further development directions for our tidal modelling framework.
关键词： change detection,Landsat,tidal,coastal,pixel-based composites
更新于2025-09-04 15:30:14
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Measuring distinct regions of grayscale image using pixel values
摘要： Grayscale is a series of shades of gray without apparent color. The total absence of transmitted or reflected light, which is the darkest shade, black. The total reflection or transmission of light at all observable wavelengths, which is nothing but lightest possible shade i.e., white. Intermediate shades of gray are characterized by equal brightness levels of the primary colors (red, green and blue) for transmitting light, or equal amounts of the three primary pigments (magenta,cyan, and yellow) for reflected light. This paper focuses mainly on measuring the properties of objects in a grayscale image using Regionprops to calculate the standard Deviation. This is achieved by segmenting a grayscale image to get objects of a binary image. Although, the common problem of including chromatic values to a grayscale image has objective solution,not exact, the present approach tries to provide an approach to help minimize the amount of human labor required for this task. We transfer the source’s whole color “mood” to the target image by matching texture information and luminance between the images rather than selecting RGB colors from a group of colors to an individual color components. We pick out to transfer only chromatic information and retain the target image’s original luminance values. Further, the procedure is improved by permitting the user to match areas of the two images with rectangular swatches. It is essential to develop grayscale image pixel value, resultant to each object in the binary image to inspect the original grayscale image.Based on the original grayscale image pixel values, the pixel value properties in grayscale image are used to do routine calculations.
关键词： binary image,regionprops,Grayscale image,pixel value
更新于2025-09-04 15:30:14
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Cascaded systems analysis of a-Se/a-Si and a-InGaZnO TFT passive and active pixel sensors for tomosynthesis
摘要： Medical imaging systems like full field digital mammography (FFDM) and digital breast tomosynthesis (DBT) commonly use amorphous selenium (a-Se) based passive pixel sensor (PPS) direct conversion x-ray detectors. On one hand, direct conversion detectors inherently offer better resolution characteristics in terms of a higher modulation transfer function (MTF), in comparison to the indirect CsI:Tl PPS x-ray imager. On the other hand, especially at lower doses, this superior performance of the direct imager is seldom retained in its detective quantum efficiency (DQE) curves. It is well known that a-Se PPS x-ray imagers suffer from high additive electronic noise originating from the from the amorphous silicon (a-Si) thin film transistor (TFT) array that is being used in the current back-plane technology. This degrades the noise power spectrum (NPS) and subsequently the overall DQE. To address this deficiency, we propose to replace the PPS back-plane by active pixel sensor (APS) back-plane technology, which has the potential to reduce the back-plane electronic noise by amplifying the input signal, especially at low doses. The proposed APS is based on amorphous In-Ga-Zn-O (a-IGZO) TFT technology, which can offer high mobility (5-20 cm2/V-s), low leakage current (< 10-13 A) and low flicker noise (Hooge’s parameter αH ~ 1.5 × 10-3), leading to better imager noise performance. To test our hypothesis, we used linear cascaded systems analysis to model the imaging performance (MTF, NPS and DQE) of the PPS and APS a-Se direct imagers. This model was first validated using experimentally measured data obtained for a 85 μm pixel pitch a-Se/a-Si TFT PPS imager. Using this model, we analyzed the noise performance of the direct a-Se and indirect CsI:Tl x-ray a-IGZO APS imagers at different dose and electronic noise levels. Obtained results clearly showed that lowering back-plane electronic noise can significantly improve the performance of the a-Se/a-IGZO TFT APS imager. Our simulated results showed that a higher DQE at lower radiation doses (maximum DQE of 0.6 can be achieved at an exposure level of 1 μGy) can be achieved with the a-Se detector, thereby making this combination a promising candidate for low dose applications like DBT.
关键词： cascaded analysis,active pixel sensors,amorphous selenium,x-ray detectors,metal oxide
更新于2025-09-04 15:30:14
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Apodized Fourier single-pixel imaging by changing the contrast of patterns using Norton-Beer functions
摘要： Single-pixel imaging has attracted a lot of attention in the last two decades, not only for its imaging ability using a low-level or non-visible light but also for imaging through scattering media. As a special method, Fourier single-pixel imaging projects sinusoids on the object and measures Fourier spectrum using a single-pixel detector. As the information of many natural objects is concentrated in lower frequencies in Fourier space, fewer measurements are required for imaging these objects using Fourier single-pixel imaging. However, the sub-sampling of the Fourier space causes ringing artifacts in the retrieved images. In this paper, we propose changing the contrast of different sinusoids based on Norton-Beer functions and show its ability to reduce ringing artifacts (‘apodized’ Fourier single-pixel imaging). This method is investigated using one- and two-dimensional simulations by implementing Norton-Beer profiles in low-pass and band-pass modes. In this way, the two modes of apodized imaging and edge enhancement are performed during the measuring process. The feasibility of these modes is experimentally proved for a simple and real object. Furthermore, different ways of using varying-contrast patterns are compared with common post-process apodization. We believe that our study can be interesting for both single-pixel imaging and image processing communities.
关键词： computational imaging,apodization,single-pixel imaging,sinusoidal modulation
更新于2025-09-04 15:30:14
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Dynamic Change Monitoring and Assessment for Sandy Land Based on Quantitative Remote Sensing
摘要： Because of climatic change and human activities, sandification is becoming a serious threat to the sustainability of human habitation. The aim of this study, therefore, was to propose a method for sandy land detection based on mixed pixel decomposition; the dynamic change monitoring and assessment was then conducted. Results showed that the pixel purity index is a viable indicator for endmember extraction for sandy land detection via remote sensing by linear mixed pixel decomposition methods. Results showed that when the endmember proportion of sandy land accounted for > 50% of the total (except for the vegetation), a pixel would be detected as sandy land. The extraction accuracy was verified to be 86.42% by field data. Early-middle August was believed to be the most reasonable time to assess sandy land coverage based on vegetation coverage. The sandy land areas in 2005 and 2014 were 5524 km2 and 4109 km2 respectively, reduced by 25.6%. Under the governance of sandy land in the last ten years, the sandy land area declined continually, but some areas were still degraded to a worse status and need special care to protect.
关键词： mixed pixel decomposition,dynamic change monitoring and assessment,vegetation coverage,sandy land detection
更新于2025-09-04 15:30:14
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Study on the Standardizaton of Signal Intensity Scale of Pixel Value in Digital Radiography
摘要： The digital radiography image shows contrast by the difference between pixel values created in accordance with absorbance difference of transmitted X-ray to object. The purpose of this study is to propose the need of standardization of pixel value representation in digital radiography image. The unprocessed images and processed images are obtained through various types of X-ray equipment and analyzed pixel values. As the result of pixel value analysis, the unprocessed images represented pixel values in accordance with X-ray signal intensity while processed images represented pixel values in accordance with gray scale. In order to understand the relationship between radiation dose and pixel value in digital radiography image, the pixel value representation which reflects X-ray signal intensity is necessary.
关键词： Signal Intensity,Gray Scale,Pixel Value,Digital Radiography
更新于2025-09-04 15:30:14
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[Lecture Notes in Electrical Engineering] Recent Trends in Communication, Computing, and Electronics Volume 524 (Select Proceedings of IC3E 2018) || Fusion of Zero-Normalized Pixel Correlation Coefficient and Higher-Order Color Moments for Keyframe Extraction
摘要： Keyframe extraction of videos is useful in many application areas such as video copy detection, retrieval, indexing, summarization. In this paper, we propose a novel shot-based keyframe extraction algorithm. The proposed algorithm is capable of detecting both shots and keyframes of any video ef?ciently. For extraction of keyframes, frames of video are clustered into shot transitions. These shot transitions of the video are obtained using higher-order color moments and zero-normalized pixel correlation coef?cients. In each shot, all the frames are scanned to detect frame with highest standard deviation in that particular shot and chosen as keyframe to that shot. The proposed method is tested on videos of personal interviews with luminaries. Performance of the proposed method is evaluated on the basis of ?ve parameters—recall, ?gure of merit, detection percentage, accuracy and missing factor. The proposed method is able to detect both abrupt and gradual shot transitions with comparatively less computational complexity. The exhaustive analysis of results shows the sound performance of the proposed method over the methods used in this study.
关键词： Color moments,Cut shot transition,Zero-normalized pixel correlation coef?cient,Keyframe extraction,Gradual shot transition,Shot detection
更新于2025-09-04 15:30:14
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[IEEE 2018 International Conference on Electrical Engineering (ICEE) - Lahore, Pakistan (2018.2.15-2018.2.16)] 2018 International Conference on Electrical Engineering (ICEE) - Active Pixel Digital Sun Sensor for Satellites
摘要： Satellites use sun sensors as a reliable source of attitude determination during sunlit conditions while in orbit around the earth. This work elucidates the design and development of high precision and wide field of view digital sun sensor for space applications. Sun sensor employs active pixel image sensor along with processing techniques of feature extraction and image correlation. Software algorithm exploits the distinctive features of Active Pixel imaging Sensor (APS), in comparison to CCD based image sensor, for computationally efficient algorithm design. Sunlight falling on the sun sensor produces an image of the sun on image sensor. Software algorithm processes this image for noise removal, feature extraction, centroid analysis and sun vector calculations. Digital sun sensor, presented here, achieves 0.018 pixels (3σ) centroid accuracy with 120°×120° field of view.
关键词： Sun Sensor,Image Correlation,Image Processing,Feature Extraction,Active Pixel imaging Sensor
更新于2025-09-04 15:30:14