A NEW METHOD FOR MEASURING OCEAN WAVE FROM SEASAT SAR REMOTE SENSING IMAGE

A new method for measuring ocean wave length and direction from SEASAT SyntheticAperture Radar (SAR)remote sensing image is presented in the paper. In the new method, an ocean waveimage is sampled in certain directions, the samples are then analyzed by using one dimensional FourierTransformation to calculate the ocean wave correlation function. Finally the ocean wave length and direc-tion are determined from the ocean wave correlation function. The new method is better than the tradition-al two-dimensional Fourier Transformation method in both consuming time and precision .     

A self-scanned image sensor employing MOS structure

Studies were carried out on a self-scanned image sensor comprising a linear integrated-circuit array of photodiodes and metal-oxide-semiconductor (MOS) transistors. It was found that the maximum scanning rate is about 2.5×10⁵bits/s, and that the value is mainly restricted by the photo-induced current and the junction capacitance of the photodiode.     

Dopant profile and gate geometric effects on polysilicon gatedepletion in scaled MOS

Polysilicon depletion effects show a strong gate length dependence according to experimental p-channel MOS capacitance-voltage (C-V) data. The effect can be influenced not only by gate geometries, but also by dopant profiles in poly-gates. These effects have been modeled and verified using device simulation. Nonuniform dopant distributions in the vertical and lateral direction in the poly-gate cause additional potential drops. The potential drop in the poly-gate becomes critical as the gate geometry is scaled down due to edge and corner depletions resulting from fringing electric fields     

1024位6相时钟MOS图像传感器

介绍一种采用６相时钟电路的１０２４位ＭＯＳ图像传感器，其像元中心距为１５μｍ，移位寄存器采用５管动态无比电路，功耗小于０．５ｍＷ，且与位数无关。器件光敏面上沉积了ＳｉＯ２增透膜，提高了光电转换效率。给出了该器件光电参数测试结果。     

A high-sensitivity MOS photo-transistor for area image sensor

A new MOS phototransistor, called a double-gate floating surface phototransistor, has been fabricated and evaluated. In the phototransistor cell, the gate area has been divided into two parts, the accumulation section and the detection section, in order to realize a low input capacitance for a high optical gain. The device achieved a noise equivalent exposure of 2×10^-4 lx at 16-ms integration time and a dynamic range of 75 dB with a new line potential modulation operation     

Maximum cross correlation automatic satellite image navigation and attitude corrections for open-ocean image navigation

To enable "automated" image navigation (without human intervention) a base image is defined, and the maximum cross correlation (MCC) method is used to automatically compute the satellite attitude parameters required to geometrically correct images to this base image. Several levels of filters insure that contamination from cloudy pixels is minimized. The MCC method produces displacement vectors, which are translated into satellite attitude corrections to be added to the orbital image navigation corrections. The auto attitude corrections are shown to be more accurate than the traditional linear translation methods. A further application of the attitude corrections is demonstrated whereby attitude corrections computed over land can be carried forward in the satellite's orbit to accurately navigate imagery over the open ocean where no map reference points are available. Tested for two land sites well separated in a single orbit this method is shown to be as accurate as when applied to an individual image.     

Degradation-free MOS image sensor with photonic crystal color filter

This letter demonstrates a long-term reliable MOS image sensor equipped with a novel photonic crystal color filter (PC-CF). PCs are periodically structured dielectric media, generally possessing a photonic band gap. In the newly developed PC-CF, it is clarified that the desirable spectral property, i.e., peak wavelength and spectral passband, can be achieved by modifying the thicknesses of the defect layers, which act just like a "defect" in a PC. The spectral characteristics with the peak wavelengths at 450 (blue), at 530 (green), and at 610 nm (red) are realized in this letter. Moreover, the fabricated image sensor guarantees high reliability of longer than 200 000 h and heat resistance of above 300 /spl deg/C.     

Sparse geometric image representations with bandelets.

This paper introduces a new class of bases, called bandelet bases, which decompose the image along multiscale vectors that are elongated in the direction of a geometric flow. This geometric flow indicates directions in which the image gray levels have regular variations. The image decomposition in a bandelet basis is implemented with a fast subband-filtering algorithm. Bandelet bases lead to optimal approximation rates for geometrically regular images. For image compression and noise removal applications, the geometric flow is optimized with fast algorithms so that the resulting bandelet basis produces minimum distortion. Comparisons are made with wavelet image compression and noise-removal algorithms.     

一种抗几何攻击的图像零水印方案

提出一种抗几何攻击的图像零水印方案。该方案不改变原始图像的数据，利用图像几何不变矩构造水印，较好地解决了水印的鲁棒性与不可感知性之间的矛盾。实验证明，水印方案对几何变换及常见的图像处理具有较好的鲁棒性。     

Analogue MOS current-mode circuits for three-dimensional integrated smart image sensor

An image processing technique using analogue MOS current-mode circuits is presented. This approach is of interest in smart image sensors based on three-dimensional (or multi-layered) VLSI structures. High-performance smart image sensors with high resolution can be realised because the number of transistors required for image processing in each pixel is greatly reduced.<>     

On exploiting geometric constraint of image wavelet coefficients

We investigate the problem of how to exploit the geometric constraints of edges in wavelet-based image coding. The value of studying this problem is the potential coding gain brought by improved probabilistic models of wavelet high-band coefficients. Novel phase shifting and prediction algorithms are derived in the wavelet space. It is demonstrated that after resolving the phase uncertainty, high-band wavelet coefficients can be better modeled by biased-mean probability models rather than the existing zero-mean ones. In lossy coding, the coding gain brought by the biased-mean model is quantitatively analyzed within the conventional DPCM coding framework. Experimental results show that the proposed phase shifting and prediction scheme improves both the subjective and objective performance of wavelet-based image coders.     

A 24/spl times/6 interlaced-scan MOS image sensor

A new 24/spl times/6 self-scanned MOS image sensor has been developed for the Optacon reading aid for the blind. This new image sensor has a unique circuit design that provides in a simple manner interlaced row scanning and low-light level detection. While a previous investigation (1969) showed that self-scanned MOS image sensors are capable of operating with illumination levels of 1 /spl mu/W/cm/SUP 2/, this report presents a working circuit to simply realize this performance in a device compatible with a reading aid application. The previous investigation also did not consider the noise at high-scanning frequencies (175 kHz) associated with package interconnection capacitances. This new circuit attempts to minimize this previously neglected switching noise.     

Method for combating random geometric attack on image watermarking

A method for amending StirMark random geometric attacked watermarked images is introduced. The proposed scheme uses a reference image to identify the attacked pixels, then exchanges them for pixels from the original unwatermarked image. It is shown that the watermark can be successfully detected after the attacked image is corrected     

A geometric model for 3-D confocal image analysis

In this paper, we use partial-differential-equation-based filtering as a preprocessing and post processing strategy for computer-aided cytology. We wish to accurately extract and classify the shapes of nuclei from confocal microscopy images, which is a prerequisite to an accurate quantitative intranuclear (genotypic and phenotypic) and internuclear (tissue structure) analysis of tissue and cultured specimens. First, we study the use of a geometry-driven edge-preserving image smoothing mechanism before nuclear segmentation. We show how this filter outperforms other widely-used filters in that it provides higher edge fidelity. Then we apply the same filter, with a different initial condition, to smooth nuclear surfaces and obtain sub-pixel accuracy. Finally we use another instance of the geometrical filter to correct for misinterpretations of the nuclear surface by the segmentation algorithm. Our prefiltering and post filtering nicely complements our initial segmentation strategy, in that it provides substantial and measurable improvement in the definition of the nuclear surfaces.     

图像几何校正控制点的自动确定方法

依据图像几何校正的一般思路，提出了一种有效控制点（CP）自动确定方法，首先定义了基准控制点（RCP）及畸变控制点（DCP）的概念，设计了一种基于图像方差的检测模板，提出了相应的检测准则及搜索方案，然后在畸变图像中利用归一化积相关图像匹配算法实现了基准控制点相对应的畸变控制点的精确定位，并给出了方法的算法流程，最后，以几何旋转畸变图像为例进行仿真实验，准确辨识出了畸变模型的参数，验证了方法的可行性有效性。     

AN EXPANSION AND CORRECTION ALGORITHM FOR PHOTOELECTRIC IMAGE WITH GEOMETRIC DISTORTION

A creepy hotoelectric endoscopy system with good performance is studied,and an expansion and correction algorithm for a compressed photoelectric image with serious geometric distortion is presented.The algorithm can not only correct the geometric geometric distortion,but also restore the gray-level distribution by means of ternary convolution algorithm.The details and the outline in the image are very clear.It is proved to be of high performance in practice.     

一种基于统计量化的抗几何攻击图像水印算法

依据图像受到几何攻击时亮度值统计特性不变原理提出了一种基于统计量化的抗几何攻击图像水印算法。用二值序列作为水印,水印嵌入时,首先选取一段亮度值范围,然后根据一定的步长将其划分为小区间,每一水印位对应一区间,最后对亮度值进行量化,使每个区间的像素都被量化到一个亮度值上。水印提取时,首先统计每个亮度值的像素个数,然后按照嵌入时的方法选取亮度范围并且划分区间,从每个区间提取一位水印信息。实验表明,这种方法对图像缩放、旋转和剪切等几何攻击有很强的鲁棒性,对中值滤波、噪声等常规攻击也具有较强鲁棒性。     

基于几何结构属性的光学和SAR影像自动配准

提出了一种基于几何结构属性的光学和合成孔径雷达(Synthetic Aperture Radar,SAR)影像配准方法.该方法引入了具有光照不变性的相位一致性模型进行影像特征提取,采用该模型的强度和方向信息构建了一种几何结构特征描述符—相位一致性方向直方图(histogram of orientated phase congruency,HOPC),并根据该描述符间的欧式距离定义了影像匹配的相似性测度(称为HOPC_n).该测度能表示影像间的几何结构相似性.通过选择4组光学和SAR影像进行试验,结果表明,HOPC_n能有效率的抵抗影像间的非线性辐射差异,并且其匹配性能好于经典的相似性测度.另外,也设计了一种基于HOPC_n自动的配准方法,试验结果证明了该方法的有效率和鲁棒性.     

Localized image watermarking in spatial domain resistant to geometric attacks

Watermark robustness to geometric attacks is still a challenging research field. In this paper, a novel robust image watermarking scheme is proposed for resisting such attacks. Watermark synchronization is first achieved by local invariant regions which can be generated using scale normalization and image feature points. The watermark is embedded into all the local regions repeatedly in spatial domain. During embedding, each circular region is first divided into homocentric cirque regions. Then the watermark bits are embedded by quantizing each cirque region into an “odd” or “even” region using odd–even quantization. In the decoder, an odd–even detector (OED) is designed to extract the watermark from the distorted image directly. Localized embedding achieves good invisibility and repeated insertion enhances watermark robustness. Simulation results show that the proposed scheme is robust to both geometric attacks and traditional signal processing attacks.     

基于几何约束的车牌倾斜检测方法

提出了一种新的基于车牌图像几何约束的车牌倾斜角自动检测算法。算法以车牌字符轮廓的最低点为基本信息,用矩的方法确定车牌的倾斜角度。本算法创新性地采用字符顶点的几何约束信息再用矩的方法得到倾斜角度。结果表明,该算法运算量小,速度快,校正精度高。