最新刊期
卷 9 ， 期 10 ， 2004
- 摘要：When point spread function(PSF)is not known or only partially determined, restoration of the degraded images is called blind image restoration (BIR). In recent years, BIR algorithms (BIRA) have been studied widely. In this paper, BIRA is classified into three kinds: single channel BIRA with space-invariant PSF, multi-channel BIRA with space-invariant PSF and BIRA with space-variant PSF, according to the characteristic of PSF. The actual research status of BIRA is discussed in detail. Here, advantages and disadvantages of BIRA are also pointed out. After researching on the techniques, some results and conclusions are given as follow: improvement for the existing BIR methods, development a new techniques, the research based on degradation model with non-linear characteristic, the removal noise, the real time algorithm and their applications are the challenges and further research tendency.4138|214|0更新时间：2024-05-07
- 摘要：Along with digital AV and multimedia technology developing, large numbers of video datum need to be compressed. At present ,the International Coding Standards, such as MPEG-1, MPEG-2, MPEG-4, H.261, H.263, H.264 have been established and applied to different application areas. In order to adapt to heterogeneous client terminals and transmission characteristic of networks, pre-encoded video should be transcoded into another coding format. So, the resources of networks can be shared. The content of this paper is about how to convert a previously compressed video bitstreams into a lower bit-rate video bitstreams according to the requirements of heterogeneous client terminals, such as bitrate transform by changing quantizer parameter, spatial resolution transform by down-sampled, temporal resolution transform by skipping frames. In this paper the architectures and mechanism of transcoder are analyzed and the best tradeoff between quality and complexity are offered. Also the core technique: how to obtain the motion vector is anatomied.2819|192|0更新时间：2024-05-07
- 摘要：Traditionally, the method of bar code recognition is based on zero crossing of the second derivative. But the performance of this method deteriorates in the case of high density bar code image, which is severely blurred by a point spread function of optical system. In order to deblur the image, deconvolution and waveform recovery are necessary. Deconvolution is an ill-posed problem. Bar code is a kind of bilevel waveform. On this condition, a novel deconvolution algorithm based on iterative computations is proposed. First, the location and segment technology of bar code is discussed and a single row codeword image is obtained. After analysing the waveform, the system identification is accomplished and the standard deviation of the point spread function is obtained. At last, the bar code waveform is reconstructed based on iterative computations. The experimental results show that the performance of the algorithm proposed in this paper is excellent. It can achieve higher recognition rate of bar code, which suffices to the requirement of the practical use.2780|185|0更新时间：2024-05-07
- 摘要：In order to overcome the shortcoming of the longtime training and the frail generalization power of classical neural networks, this paper proposes a new covering classification algorithm based on constructive neural networks. The algorithm starts with the sample data directly and clustering analysis is executed on a hypersphere to find a sample with the max density, and then the intersection between the positive half-space of the hyperplane and sphere, called“sphere neighborhood”, is obtained, by which the training problem of neural networks may be transformed into the covering problem of point sets. Thus the new algorithm can reduce the traditional learning complexity. At the same time, the optimization of the neural network is also considered and computer simulation results show that the proposed neural network is quite efficient.2773|189|0更新时间：2024-05-07
- 摘要：This paper proposes a structure-context based fuzzy neural network(SCFNN) approach for automatic target detection. Fuzzy neural network methods not only possess advantages as adaptivity, parallelism, robustness, ruggedness, and optimality, but integrate advantages as depicting and solving system uncertainty by knowledge and rules of fuzzy set theory. Accordingly, they are powerful tools for image processing and pattern recognition. Use fuzziness measures as objective function of neural network can depict uncertainty of pixels' category validly so as to optimize image classification by minimizing the objective function. Puting information constraint of structure context on neurons' weighting process can reduce loss of image information, especially, the rich information comprised by target edges, by which target's attributes such as profile and shape can be retained validly, and the false detection rate can also be improved prominently. Experiments on remotly sensed images of target are executed to validate SCFNN approach. The results exhibit that SCFNN possesses good ability to automatic target detection, simultaneously, possesses valid abilities to eliminating uncertainty and retaining target shape compared with conventional neural network methods.2294|188|0更新时间：2024-05-07
- 摘要：In aerial images, a good description for window textures is of great significance for building extraction. In this paper, based on the result of vertical line extraction, the time-frequency analysis and the Radon transform are used to describe the directivity and periodicity of widow texture. First, in order to acquire periodic texture signals, gray-levels down the vertical lines are picked-up; and in order to enhance signal's robustness for noise and to catch the transversal orientation of texture, gray-levels along several quantitative directions are accumulated based on vertical lines, just like the well-known Radon transform. Second, the Fourier spectrum analysis is adopted to deduce the existence of window texture and its transversal orientation (namely the horizontal orientation of wall). With this understanding, the reliability of corresponding vertical line is ensured. However, its actual pixel positions are needed to be verified furthermore. To do so, the short-time Fourier spectrum of texture signal is computed sequentially, and the part with the same periodicity indicates the accurate location of vertical line. Lastly, the experimental results demonstrate that, reasonable analyses of window texture can be used to acquire reliable evidences for the presence of buildings and exact locations of their vertical lines, and to calculate local horizontal orientations of walls. The proposed algorithm provides a new favourable approach for the detection and acquisition of 3D information of buildings.2424|204|0更新时间：2024-05-07
- 摘要：Edge map is an important representation of human face image. It is of significance for automatic face image analysis. This paper presents a new method for the extraction of face image edges and a scheme for facial expression analysis based on the resulting binary edge images (BEI). Making use of the multi-resolution property of wavelet transform, the edge detection method includes two binarization steps and a noise removing step. Our method provides a robust solution to face image edge extraction, in particular, if changes of lighting conditions are encountered. Experimental results show that different components in a BEI are well separated and pixels of the same face component are connected well. Preliminary experimental results on facial expression analysis on the subsets of AR and Yale face databases show that recognition rates of above 93% can be achieved when our facial analysis scheme is used for recognizing four action units.2736|174|0更新时间：2024-05-07
- 摘要：The goal of digital image inpainting is to restore damaged regions or remove objects in the image. This paper presents a novel image inpainting algorithm based on RBF (radial basis functions). After the user selects the regions to be inpainted, the algorithm automatically detects contours of the mask and finds appropriate regions to construct the RBF. Color of the 2D image is treated as height field over a regularly sampled grid, the 2D image inpainting problem is naturally converted to 3D implicit surface reconstruction problem, which RBF has been proved to be a good solver. With RBF resampling,the algorithm can nicely fix the damaged image or remove specific objects. Experiments show that our algorithm can fix a large variety of images effectively and robustly.3360|283|0更新时间：2024-05-07
- 摘要：Image super-resolution restoration and enhancement (SR) based on reconstruction is a typically ill-posed and high-dimensional problem, which needs effective regularization to stable the solution. Lately a parametric and regularized blind SR( RPSR) was proposed by Nguyen et al, which has set up a frame work for the blind SR. Under the frame of RPSR, in this paper, an adaptive RPSR(ARPSR) based on image locale smoothing characteristics is put forward, and for the conveniences of computing, an approximate ARPSR is proposed also, by which at first the ARPSR problem is transformed into a weighted combination of two RPSR problems, then the optical blurring and regularization free parameters are estimated by the standard RPSR frame, and then by exploiting the structures of the reordered system matrices, a preconditioner is constructed for the preconditioned conjugate gradient method(PCG) by which the high-resolution image is solved at last. Computational analyses and experimental results with synthetic low-resolution sequences show the improvements of ARPSR to the RPSR frame.2107|236|0更新时间：2024-05-07
- 摘要：This paper gives a thorough study on video robust transmission over the noisy channel in wireless network. A novel method to enhance the ability for error resilient video transmission is proposed. In order to obtain better reconstruction quality and enhanced error concealment performance at the decoder with a H.263 baseline function, the block classification and edge orientation information,bit-length value of macro block and other information about current block are organized together in binary form by the encoder as an indicator used for achieving detection,resynchronization and reconstruction of the errors and lost data in received video sequence. A fast classification algorithm based on calculated DCT domain matrix coefficients is employed in the proposed approach to extract numerical classification information and edge orientation value of image blocks. And all these information is imperceptibly embedded into image frame bit-stream by even-odd signaling forcibly of the DCT coefficients which has improved reduction of the visual loss and influence of image caused by modified DCT coefficients with a view of counting coefficient integral difference. Experiments and simulations on typical video sequences show that the proposed approach has a significant improvement in transmission performance against conventional techniques used in standard baseline H.263 encoder and decoder without changing the transmitted bit-stream syntax and increasing computation cost and complexity.2175|168|0更新时间：2024-05-07
- 摘要：This paper investigates the problem of how to carry out 3D projective reconstruction from multiple images. Up to now, it is commonly accepted that the bundle adjustment and factorization method are the main methods for projective reconstruction. But the bundle adjustment needs a good initialization and extremely expensive computation, and the factorization method is limited by the restriction that all 3D points must be visible in all views. Recently, a linear algorithm of projective reconstruction based on the homography induced by the infinite plane was given by Hartley and Rother et al., but they needed 4 points on a reference plane be visible in all views. This paper improves their algorithms and proposes a new linear algorithm based on infinite homography where 3 points on a reference plane should be visible in all views. It avoids the difficult task of determining whether 4 object points are coplanar or not, because 3 points which are not collinear just determines a plane. The algorithm proposed in this paper is convenient and can deal with the occluded problem. The algorithms are evaluated on both synthetic and real world images and the experiment results show that the method is accurate and only affected slightly by noise.2685|187|0更新时间：2024-05-07
- 摘要：This paper presents a new specification of LDM-Pack tree, which renders trees rapidly with high fidelity. It first samples the tree model, and gains its LDI-Packs. All LDI-Pack textures are compressed by an occlusion-inclusive compression approach, and packed into texture packages. Then the corresponding LDM-Packs are created from LDI-Packs according to the predetermined viewpoints. Thus, a tree is specified by a group of LDM-Packs with several sample directions. When rendering stage, one blending scheme is used to render correct LDM-Packs for smooth transitions. Shown by the experiments, the number of rendering depth mosaics is less than the one of the tree original polygons.2446|206|0更新时间：2024-05-07
- 摘要：The main aim of digital image scrambling, which is used as the pre-processing or post-processing in image information hiding, is to transform a meaningful image into a meaningless or disordered image in order to enhance the power to resist invalid attack and in turn enhance the security. This paper introduces the academic foundation of S-box that is usually applied to group cryptosystem with image information security as its background, and then presents a method of digital image scrambling based on S-box and discusses the periodicity of the arithmetic. The algorithm is proved to be efficient with experiments.2526|151|0更新时间：2024-05-07
- 摘要：A DCT-domain watermarking algorithm with 8 bits gray image's watermark is proposed. First, the method of block classification based on HVS is improved, which enhances the information hiding ability of cover image. In the watermark embedding process, we transform the image's watermark into DCT domain, and embed the low-frequency coefficients to the blocks that have bigger elongation factor. At the same time, we adjust the DCT coefficients of image's watermark to make them in the same level. This increases the SNR of extracted watermark. The experimental results show that the mentioned algorithm is more robust to many attacks, especially to JPEG compression, rotation and cropping.2489|198|0更新时间：2024-05-07
- 摘要：Edge detection analysis for gastric tumor pathologic cell images by mathematical morphology is introduced here. The main purpose of the research is to lay a foundation of analysis and recognition for cellular morphology by the watershed segmentation and the information fusion of the images. In the paper, gray-scale edge detection methods of morphologic principle for the cell images are brought forward, whose experimental results are achieved. By comparing with the traditional edge detection methods, it is proved the advantages of the edge detection of mathematical morphology for the research of gastric tumor pathologic cell images. Combining with the texture features of investigated image, the paper has discussed the effect to the image edge detection with various configuration elements and gray-scale threshold values.2369|221|0更新时间：2024-05-07
- 摘要：In medical domain, the Computed radiography image system comes into a brand-new development. Image segmentation takes an important place in medical image processing. Different segmentation methods used in medical images cause different effects due to the particularities of medical images. With digital chest radiographs as research objects in this paper, several segmentation methods are presented to detect the ribs in digital chest radiographs, which include iterative probabilistic relaxation, K-means clustering and Gaussian curve plane threshold methods, etc. The evaluations of their results are given in the end of the paper. The experimental results indicate that Gaussian curve plane threshold method is more effective than the others to detect the ribs in digital chest radiographs. By using it, subsequent processing can be simplified and full information of the ribs can be obtained, so more reliable experiment data can be supplied to subsequent computer aided diagnosis.3142|202|0更新时间：2024-05-07
- 摘要：The research on the cardiovascular and cerebrovascular hemodynamics can help to interpret the cause of disease and diagnoses of the cardiovascular and cerebrovascular disease. It is important to collect and analyze the blood flow activity. Now Doppler Ultrasound is the newest technique to supply the data of the cardiovascular and cerebrovascular hemodynamics non-invasively, simply and effectively. In this paper, a digital system was designed. It can get the frequency spectrum image of Doppler Ultrasound's activities. Through the analysis and research on the output data format of a printer, the frequency spectrum image will be stored by the familiar format of image files. With the image manipulation technique, the time series data of the blood flow activity can be obtained and they are fit for various nonlinear analysis. By the system the original blood flow activity can be observed, and the changes of the data in the experiments can also be detected real-timely. It is proved by actual examples that this system is feasible, and the time series data of the blood flow activity obtained are exactly. It can offer assistance for the further study of the cardiovascular and cerebrovascular disease. It can also provide the foundation for uniting nonlinear science and ultrasonic diagnosis in medicine.2290|178|0更新时间：2024-05-07
- 摘要：Coastline was one of the earliest object in the fields of fractal research. However, the fractal dimension of coastline in one country has not been studied systematically so far. In this paner, programs are designed to calculate two kinds of fractal dimensions—box-counting dimension and divider dimension. Meanwhile, the method and the principle by which the complexity of the coastline is analyzed have been put forward through computing the fractal dimension of the common printing map and the electronic map. And for the first time, the complexities of the coastline computed by different scales, computational methods and modes of map are compared and analyzed. On this base, conclusions of the complexity of the coastline of the Chinese maritime provinces are drawn . The fractal dimensional value calculated by divider method is always bigger than that by box-counting method. The variety of the geographical constitution and aboriginal physiognomy from north to south is approximately consistent with the variety trend of the fractal dimension. To the electronic maps with the same precision and different scale, the fractal dimension goes along with the scale.2440|189|0更新时间：2024-05-07
- 摘要：The paper analyzes the problems existed in WebGIS that traditional WebGIS is independent and isolated and there is no sufficient interoperability among different systems. Then the paper discusses the application of XML on WebGIS in two aspects, namely the data interoperability and the function interoperability. After this, a schema for open WebGIS based on XML is proposed. Since the schema is designed with the open technologies, so it is different from the traditional one. The system devoloped according to the schema is interoperable, extensible and interactive. Finally based on the above schema, a prototype system is developed to test the theory correction and technique feasibility of the schema. With the prototype, some tests for the integration of the heterogeneous geospatial data are implemented and some satisfied results are achieved.2448|185|0更新时间：2024-05-07
- 摘要：This paper looks into the so called“Binary Mapping Law”for histogram specification presented in[1] (ZHANG Zhuan-cheng,et al. A binary mapping law(BML) for histogram processing of digital image. Journal of Image and Graphics, 2004,9(3):280～284) and points out that it is identical to the“Group Mapping Law” presented in[2](Zhang Y J. Improving the accuracy of direct histogram specification. IEE Electronics Letters, 1992,28(3):213～214). This paper also looks into the histogram equalization method presented in[1] and indicates that it is different from the histogram equalization method resulted directly from histogram specification and a thorough assessment of the performance of this method needs some more general criteria for evaluationg the performance of histogram equalization techniques.2765|205|0更新时间：2024-05-07
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