In this paper, we derive the optimal structuring elements of morphological filters in image restoration. The expected pattern transformation of random sets is presented. An estimation theory framework for random sets ...
详细信息
ISBN:
(纸本)081941638X
In this paper, we derive the optimal structuring elements of morphological filters in image restoration. The expected pattern transformation of random sets is presented. An estimation theory framework for random sets is subsequently proposed. This framework is based on the least mean difference (LMD) estimator. The LMD estimator is defined to minimize the cardinality of the expected pattern transformation of the set-difference of the parameter and the estimate. Several important results for the determination of the LMD estimator are derived. The LMD structuring elements of morphological filters in image restoration are finally derived.
This paper describes an object recognition technique based on the concept of local symmetry. A technique is described which can detect 1D features under situations of extreme low contrast. The effectiveness of the tec...
详细信息
ISBN:
(纸本)081941638X
This paper describes an object recognition technique based on the concept of local symmetry. A technique is described which can detect 1D features under situations of extreme low contrast. The effectiveness of the technique is shown through application to DNA autoradiographs. The technique is then expanded so that 2D objects can be located and then recognized. In the 2D case the resulting output of the technique is a locus which can be compared to those in a database. It is further shown how the technique is robust against changes in both scale and orientation.
A current topic in image coding is to investigate how the efficiency of conventional waveform coding can be improved by utilizing methods from image analysis, image segmentation, image understanding and computer visio...
详细信息
ISBN:
(纸本)081941638X
A current topic in image coding is to investigate how the efficiency of conventional waveform coding can be improved by utilizing methods from image analysis, image segmentation, image understanding and computer vision. A very promising approach to this problem is object- oriented analysis-synthesis coding and its combination with conventional waveform codecs (hybrid waveform/object-oriented coding). One of the most important key components needed for such a hybrid system is a reliable and generic image segmentation. In this context the underlying contribution presents an algorithm for segmenting objects in front of moving backgrounds. This algorithm is based on four subsequent processing steps which are explained in detail: pre-segmentation by using a Hough transform of conventionally estimated vector fields, global parameter mapping within the pre-segmented background area, compensation of the global background motion, thresholding and post-processing of the remaining DFD signal.
A new hybrid coding scheme for video sequences is presented. With the introduction of a fast quadtree motion segmentation algorithm, motion vectors are estimated with variable size block matching which produces better...
详细信息
ISBN:
(纸本)081941638X
A new hybrid coding scheme for video sequences is presented. With the introduction of a fast quadtree motion segmentation algorithm, motion vectors are estimated with variable size block matching which produces better performance considering both overhead motion information and motion compensated prediction error. Small blocks containing high motion activities are intraframe vector quantized, whereas large blocks representing smooth motion areas are first decimated and then interframe vector quantized. Simulation results demonstrate that the proposed scheme performs very well.
This paper describes a method for coding arbitrarily shaped image segments. The method uses an iterative technique based on the theory of successive projection onto convex sets to determine the best transform coeffici...
详细信息
The model-based image coding might be the potential method for very/ultra low bit rate visualcommunications. However, some problems still remain for video practice, such as a finer wireframe 3-D model, precise rule f...
详细信息
ISBN:
(纸本)0819416223
The model-based image coding might be the potential method for very/ultra low bit rate visualcommunications. However, some problems still remain for video practice, such as a finer wireframe 3-D model, precise rule for facial expressions analyzing, and automatic feature points extraction for real time application, etc. This paper proposes a feasible scheme of model-based image coding based on a deformable model which would be suitable for very/ultra low bit rates transmission. Meanwhile, some key techniques, such as automatic face feature point extraction based on a priori knowledge for real time applications and the method of AUs separation of a face on various expressions, is given.
A new version of the Fourier Convolution algorithm in Computed Tomography is created by modifying the filter function, considering the phantom as a matrix of square pixels and taking the ray sum width equal to the pix...
详细信息
ISBN:
(纸本)081941638X
A new version of the Fourier Convolution algorithm in Computed Tomography is created by modifying the filter function, considering the phantom as a matrix of square pixels and taking the ray sum width equal to the pixel side. Each ray sum has a number of pixels which are partially covered by the ray sum width. This creates a weighting factor which is the correlation vector between the scanning beams and the phantom pixels. Each pixel is reconstructed more than once in each projection. A comparison of the reconstructed variable between images obtained by using the Shepp and Logan filter and the modified filter is presented. Also, the comparison between the Fourier algorithm and the new version is illustrated to compare the image quality and the running time.
This paper studies the performance of an image sequence model based on Compound Random Fields when used for segmentation purposes. The fact of using a hierarchical model allows characterizing separately the texture an...
详细信息
ISBN:
(纸本)081941638X
This paper studies the performance of an image sequence model based on Compound Random Fields when used for segmentation purposes. The fact of using a hierarchical model allows characterizing separately the texture and contour information within the sequence. Moreover, temporal and spatial contour behavior can also be described independently. This separated characterization allows to impose constraints on the kind of contours to be obtained and to introduce some a priori knowledge in the segmentation procedure. The way to exploit these features for an object-based sequence coding scheme is analyzed. The influence of the model parameters on the segmentation results is analyzed, in order to achieve segmentations which can be easily coded. The main sought characteristics are smooth spatial contours, slow temporal variations and homogeneous textures. Two different segmentation algorithms are used for this analysis, a recursive and a nonrecursive one.
This paper describes a texture coding technique mainly suitable for segmentation-based coding schemes. The main features of the proposed technique are its efficiency in terms of bits per pixel for homogeneous regions ...
详细信息
ISBN:
(纸本)081941638X
This paper describes a texture coding technique mainly suitable for segmentation-based coding schemes. The main features of the proposed technique are its efficiency in terms of bits per pixel for homogeneous regions and its ability to deal with local inhomogeneities that may be present in the image. The basic idea of the coding strategy is to divide the image into blocks and to classify the blocks in two categories: Referable and Nonreferable. Referable means that the block can be approximated by one block of the already transmitted texture and nonreferable is defined by opposition. Nonreferable blocks are transmitted with a general purpose coding scheme (for example a DCT-based technique) and referable blocks are transmitted by means of a simple transition vector indicating which sample of the transmitted texture has to be translated. We show that this technique is suitable for texture but produces distortions for strong contours. As a result, we propose to use it within a segmentation-based coding scheme where contours are transmitted by another strategy. Finally, the application to sequence coding is discussed. It is shown that this technique is particularly attractive to code the prediction error within a motion compensated video coding scheme.
This paper is concerned with the data compression and interpolation of multi-view image. In this paper, we formulate the compression and interpolation problem of 3D image and propose a novel coding scheme of autostere...
详细信息
ISBN:
(纸本)081941638X
This paper is concerned with the data compression and interpolation of multi-view image. In this paper, we formulate the compression and interpolation problem of 3D image and propose a novel coding scheme of autostereoscopic 3D images. First, we introduce a general representation of an autostereoscopic 3D image and explain the concept of `space coding'. In this concept, multi-view image can be regarded as sampled data of the `space', and the objective of transmitting multi-view image can be considered as the reconstruction of the `space' in the remote site. From this viewpoint, we then examine the 3D structure extraction coding. In the experiment, we assume a simple wireframe model and evaluate the coding efficiency in terms of the bit rate and SNR is decoded images. Finally, we report the experiment, where two sets of multi-view images were used as original images and the amount of data was reduced to 1/20 with SNR 34 dB.
暂无评论