The transmission of moving pictures can be modeled mathematically by a relation between 2 functions of 3 variables. From the requirements of linearity and space and time invariance it follows that this relation can be...
详细信息
The transmission of moving pictures can be modeled mathematically by a relation between 2 functions of 3 variables. From the requirements of linearity and space and time invariance it follows that this relation can be described by convolution or equivalently using Fourier theory. Almost all practical transmission systems are sampling systems. A function of 3 variables can be reconstructed from its values on parallel planes, lines, or regularly spaced points. Sampling can equally well be described in the Fourier domain. In this paper especially the transmission of moving pictures by television is regarded.
Textured regions pose problems for segmentation algorithms whether they are based on boundary detection or thresholding techniques. First order statistical measures based on local measures of gray level patterns (loca...
详细信息
Textured regions pose problems for segmentation algorithms whether they are based on boundary detection or thresholding techniques. First order statistical measures based on local measures of gray level patterns (local properties) can be used as features for segmentation or for classification of textured regions. An analysis technique for local properties is described. Several local properties for measuring the graininess and directionality of a textured region are presented, analyzed, and evaluated on a set of test images. The results of the analysis procedure are verified by comparison with the performance on test images.
Methods are discussed for obtaining descriptions of three-dimensional objects by examining slices through spaces in which such objects are embedded. The output description is a graph whose nodes are 13-tuples (represe...
详细信息
Methods are discussed for obtaining descriptions of three-dimensional objects by examining slices through spaces in which such objects are embedded. The output description is a graph whose nodes are 13-tuples (representing generalized cylinders) and whose edges are relationships between component cylinders. The transformation is robust (in a peculiar sense) with respect to translation and rotation. Identification of complex objects from dictionary entries is feasible. Application areas include the analysis of serial tomograms and serial sections of biological objects. Methods which might simulate human reasoning from slices are discussed.
Several software engineering techniques are proposed for the implementation of a more efficient Error-Correcting Tree Automata (ECTA). The production rules of a tree grammar are transformed into suitable internal code...
详细信息
Several software engineering techniques are proposed for the implementation of a more efficient Error-Correcting Tree Automata (ECTA). The production rules of a tree grammar are transformed into suitable internal codes by a lexical analyzer during the preprocessing phase;thus, several more efficient searching algorithms such as binary search, hashing techniques or table lookup can then be used to improve the parsing efficiency. A parallel parsing algorithm of tree languages is then introduced. Comparisons of speed gain versus overhead of parallel algorithms are presented. Illustrative examples include the application of the proposed parallel algorithms to the interpretation of LANDSAT data and the discrimination of textures. Simulation results of the proposed parallel algorithm are presented.
The classification of white blood cell neutrophils into band neutrophils and segmented neutrophils is a subtask of the white blood cell differential counting. Machine classification of neutrophils started with digitiz...
详细信息
The classification of white blood cell neutrophils into band neutrophils and segmented neutrophils is a subtask of the white blood cell differential counting. Machine classification of neutrophils started with digitizing the cell images through two color filters (blue and yellow). The scene analysis algorithm divided the images into nucleus, cytoplasm, background and red cells (if present). Using the best 17 features, from a set of 367 features, Bayes classifier with Gaussian assumption, error rates of 9. 8% and 18. 2% were obtained with 378 samples by the resubstitution and the leave-one-out methods of error estimation respectively.
image understanding systems are faced with two fundamental problems: the complexity of the image understanding process and the ubiquitous presence of ambiguity and noise. A hierarchical relaxation system is presented ...
详细信息
image understanding systems are faced with two fundamental problems: the complexity of the image understanding process and the ubiquitous presence of ambiguity and noise. A hierarchical relaxation system is presented that confronts both of these problems simultaneously. At one level the system attempts to reduce ambiguities in the assignment of oriented unit line-segment labels to locations in an image. At a second, higher level, relations are defined over these labels indicating whether neighboring segments should be connected, i. e. , whether they form part of a larger line or curve. In addition, information flows between these two levels to ensure that labels at similar positions but different levels of abstraction are consistent in interpretation. An example of this system operating on a noisy image is shown.
An imageprocessing system guided interactively by the user is being developed to extract data on motion from films and videotape. Difficult problems of object and feature detection and selection are easily solved by ...
详细信息
An imageprocessing system guided interactively by the user is being developed to extract data on motion from films and videotape. Difficult problems of object and feature detection and selection are easily solved by the user. The tedious task of tracking the movement of object features through thousands of frames is handled by the imageprocessing computer. A description is given showing how optimal sequential estimation techniques Kalman filtering) can be applied to tracking. An example is given showing how the system model is built into the tracker and how the output estimates guide the process. Mainframe simulation studies are being done in addition to minicomputer-based tracking on 16mm films.
The recognition of pre-cancer abnormalities in Pap smear images by computer is discussed. Classification systems discussed treat these images as the source of feature vectors that are multi-modal and can be classified...
详细信息
The recognition of pre-cancer abnormalities in Pap smear images by computer is discussed. Classification systems discussed treat these images as the source of feature vectors that are multi-modal and can be classified using the Bayes decision model with knowledge of the various subclasses that comprise the sample. A cell classification system must be capable of using information about the various subclasses of normal and abnormal cells. Two parametric decision rules are shown which are applicable to this multi-modal problem, and are suitable for the classification required for automated detection of atypical cells in a cervical smear. Test results from a series of experiments indicate that correct recognition rates of about 85% can be achieved on the atypical cells, while maintaining an error rate of about 1% on the normal cells.
Quantitative analysis of lung tissue will generate useful information for better understanding of pulmonary anatomy and correlation of anatomy with physiology. The basic features characterizing the lung tissue which c...
详细信息
Quantitative analysis of lung tissue will generate useful information for better understanding of pulmonary anatomy and correlation of anatomy with physiology. The basic features characterizing the lung tissue which can be obtained by computer analysis of the photomicrographs include the number of object profiles within a test region, the total area of the object profiles, the total length of test lines, and the number of object profile intercepts. By applying quantitative stereology, three-dimensional properties of the lung are determined from the two-dimensional photomicrographs.
The problem examined is that of reconstructing a three-dimensional internal distribution using projection data taken with a number of suitably chosen cone-beam x-ray sources located outside the object of interest. For...
详细信息
The problem examined is that of reconstructing a three-dimensional internal distribution using projection data taken with a number of suitably chosen cone-beam x-ray sources located outside the object of interest. For a given exposure interval, the use of the cone-beam x-ray sources would provide information about the anatomical distribution within a volume rather than within a single slice. A times series of azimuthal scans taken with hardware consisting of electronically-switched stationary sources and detectors should provide sufficient data for fully four-dimensional image reconstructions that would permit detailed studies of the dynamic heart.
暂无评论