Showing papers on "Top-hat transform published in 1991"

Color image processing system for preparing a composite image transformation module for performing a plurality of selected image transformations

Abstract: A method and apparatus for generating an array of modified pixel values in response to an array of input pixel values. The apparatus includes a user interface for receiving a user's selection of an image transformation(s) to be performed on the array of input pixel values. A storage device stores a plurality of transform definitions, each transform definition including sample values representing an input/output relation of an image transformation. A transform controller selects a plurality of transform definitions in response to the user's selection of at least one image transformation, and generates therefrom a composite transform definition. The composite transform definition includes sample values of an input/output relation of a composite image transformation which is equivalent to the image transformation(s) selected by the user. The transform definitions stored by the storage device include a plurality of predetermined transform definitions. A custom transform definition can be prepared in accordance with a user's instructions and added to the plurality of transform definitions stored by the storage device. The transform controller operates in essentially real time, implementing the user's selections sufficiently quickly to allow the user to interact with the image processing system until a desired array of modified pixel values are obtained.

System for transmitting encoded image data with quick image expansion and contraction

Abstract: A system for transmitting encoded image data capable of transmitting the multiple view image data, without causing a significant level of an increase of a size of the system, a delay in a data transmission, and a limitation on a number of communication channels. The system includes: an image encoder for encoding orthogonal transform coefficient data obtained by applying an orthogonal transform to image data, and transmitting encoded image data in which the encoded orthogonal transform coefficient data are classified according to their degrees; an image processing for transmitting processed image data containing the encoded orthogonal transform coefficient data in the encoded image data along with a size change rate information indicating a size change rate by which a size of the image data are to be changed; and an image decoder for decoding the encoded orthogonal transform coefficient data in the processed image data into a degree corresponding to the size change rate indicated by the size change rate information in the processed image data by applying an inverse orthogonal transform of said degree to the encoded orthogonal transform coefficient data.

Fractal transform compression board

Abstract: Digital image data compression apparatus includes a controller circuit for receiving digital image data and for processing the image data into blocks. The controller circuit supplies processed image data to a plurality of transform circuits and to a feeder circuit. The transform circuits receive data from the controller circuit and the feeder circuit, and provide parallel processing to compare blocks of image data and generate fractal transform values representing the image data in a compressed form.

Image encoding method and apparatus

Abstract: This invention relates to an image encoding method and apparatus and, more particularly, to determination of an encoding parameter. According to this invention, a method of determining a parameter for encoding an image to be encoded in accordance with an encoding parameter of the already encoded image is disclosed.

Folding-order image forming apparatus

Abstract: In a folding-order image forming apparatus, image data provided by reading an original image are stored to a page memory. When a copy is made in an electrostatic photographic process in accordance with the image data, the read image data are processed to divide the original image into a plurality of divisional images. Required images with respect to the divisional images are rotated, rearranged and outputted by the operation of a page memory control circuit in accordance with a divisional number of a recording image, etc. Thus, the images are formed in an opening shape by folding or cutting a sheet of recording paper along a divisional boundary of images thereon. The image forming apparatus generally has an image signal memory for storing a digital image signal, a memory region controller for controlling an operation of the image signal memory in a memory region thereof and an image rotational processor for rotating an image by judging the necessity of rotational processing of an image every memory region of the image signal memory.

Image processing apparatus having apparatus for correcting the image processing

Abstract: An image of an elevator hall or an inside of elevator car is acquired by photographing apparatus, and the number of waiting passenger is detected by comparing the above-mentioned image with a background image when no passenger is present at the elevator hall. Second image processing apparatus with high precision is prepared by the same image information as that of first image processing apparatus, teacher information derived therefrom is compared with an output from the first image processing apparatus. If the teacher information is not coincident with the output from the first image processing means, parameters required for performing the image process by the first image processing appartus, for instance, constants, threshold values and weight coefficients employed in an image processing algorithm are adjusted.

Technique for use in a transform coder for imparting robustness to compressed image data through use of global block transformations

Abstract: A technique for use in, illustratively, a transform coder for imparting robustness against burst (or similar) errors to data patterns, such as illustratively two-dimensional image data, that exhibit local redundancy. Robustness is provided, in the case of images, by passing localized (blocked) image data, i.e. either pixel values or transformed, illustratively discrete cosine transform (DCT), image coefficient values therefor, through a global block transform, such as a global block Hadamard transform, prior to compression coding in order to produce "holographic-like" compressed data for subsequent transmission and/or storage. Specifically, globally transforming an image in this fashion effectively spreads (diffuses) the image data in each block of pixels in that image or in the transform coefficients therefor in a regularly ordered pre-defined global manner throughout the entire image to create what is, in effect, intentionally "smeared" image data. By subjecting the "smeared" image data upon de-compression to an inverse global block transformation, such as an inverse global block Hadamard transformation, then, even if a portion of the "smeared" data for an image is obliterated during transmission or playback, the entire image can still be advantageously reconstituted, though at a somewhat degraded quality, from the remaining "smeared" data.

Image information signal processing apparatus for improving reproduced image quality by discriminating the type of input image and selecting a particular processing in accordance therewith

Abstract: In an image display system, a picture quality improving circuit is provided for comparing a distribution, in a pixel array of a specified size, of image characteristic signals derived from image information signals each indicating one pixel of the input image with a previously examined distribution of image characteristic signals corresponding to each type of image, to thereby discriminate the type of input image. Further, a binary encoding/dithering selecting circuit responsive to the decision made on the picture type by the image quality improving circuit is provided to binary encode the image information signal applied to the image information output device on the basis of a fixed threshold value, or to dither the image information signal on the basis of variable threshold values, in accordance with the discriminated type of input image. Image information signals corresponding to a character/line image are binary encoded by the fixed threshold value, and the image information signals corresponding to a halftone image or a continuous-tone picture are dithered.

The role of amplitude and phase of the Fourier transform in the digital image processing

Abstract: The analysis of the importance of the amplitude and the phase of Fourier transform has been carried out by means of combining these functions between two images and observing the reconstructed image after a second transform. This processing has been studied by taking into account several possibilities, especially for very structurally different images. It is proved that the phase carries the most relevant information, but when common images are combined with images constituted by strongly marked geometric forms it is not so evident and the amplitude could play a more important role.

Recursion and Feedback in Image Algebra

Abstract: Recursion and feedback are two important processes in image processing. Image algebra, a unified algebraic structure developed for use in image processing and image analysis, provides a common mathematical environment for expressing image processing transforms. It is only recently that image algebra has been extended to include recursive operations [1]. Recently image algebra was shown to incorporate neural nets [2], including a new type of neural net, the morphological neural net [3]. This paper presents the relationship of the recursive image algebra to the field of fractions of the ring of matrices, and gives the two dimensional moving average filter as an example. Also, the popular multilayer perceptron with back propagation and a morphology neural network with learning rule are presented in image algebra notation. These examples show that image algebra can express these important feedback concepts in a succinct way.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Image transforming apparatus

Abstract: An image transforming apparatus forms an output image by mapping input image onto a three-dimensional curved surface, and obtains a position of a region on an input image corresponding to a position on the output image where image information becomes discontinuous. After a blanking signal is inserted into this region of the input image, an output image signal is formed by interpolating process on the basis of an input image signal with the blanking signal inserted.

Adapting transform coding to texturally segmented images

Abstract: Nonstationarity in image textures requires implementation of variable-size partitioning into stationary regions for coding purposes. The popular methods in regular decomposition fail in accurately following the various region boundaries. In the present work, the boundaries of different textures in the image are detected using a one-dimensional model of each row of the image. The autoregressive algorithm operates in 8 directions to enable an efficient detection of the boundaries. The edge map is then achieved by taking the result of edge detection operation in all directions into account. Transform coding and run-length coding are applied to encode the textures and the boundaries, respectively. >

Shading-compensation method and device in image processing

Abstract: In an image processing system in which shading-compensation for eliminating shading-distortion contained inevitably in image light directed to an image sensor via optical systems is carried out, at least two latch unit for temporarily storing comparative values obtained by scanning white and black image planes are disposed between memory means for the comparative values and a processing unit for compensating image signals obtained as a result of optically scanning a given objective image. Since the comparative value of the pixel subsequent to a pixel in process is rendered on standby in one of the latch units in preparation for the image processing for the subsequent pixel, the processing time can be remarkably increased consequently to speed up the image processing.

A Fast Morphological Filter For Enhancement Of Angiographic Images

Abstract: In this paper we present an algorithm for enhancement of angiogra hic images using morphological opening filter. Opening ora gray-scale image by a gray-scale structuring element(SE) can generate a background image. To remove the background image , we can subtract it from the original image. Usually, there are a large number of computations involved in gray-scale opening operation. We present a skipped SE algorithm which can significantly improve the processing speed, and yet gives excellent enliancement for the angiographic images.

Nonlinear filters for image sharpening and smoothing

Abstract: A general approach to the transform-magnitude-shaping-based image enhancement method is advanced. In the method, the magnitude of the input image transform is modified using a nonlinear mapping expressible as a power series, while its phase is kept invariant. The inverse transform of the modified image transform results in a sharpening or smoothing depending on the choice of the power series coefficients. Further improvement in the overall enhancement is achieved by a two-channel processing scheme which is implemented by applying different transform amplitude shaping methods to the low-frequency and high-frequency components. Examples the proposed enhancement method are included. >

Two new image compression methods utilizing mathematical morphology

Abstract: In this paper, two control point-based image compression methods are presented In the first method, the encoding is based on the roughness of the surface defined by the gray levels of the image The second method utilizes a new distance transform, called the Distance Transform on Curved Space (DTOCS) The related compression ratios of both of the methods are very good Also the computations needed are quite simple and require only a short processing time The study includes the investigation of properties of the control point-based interpolation

Edge extraction by active defocusing.

Abstract: A novel edge extraction method that employs an active defocusing technique is presented. The method is based on the principle that a Laplacian-of-Gaussian (LOG) operation can be approximated by a Difference-of-Gaussian (DOG) operation. While such an operation is usually done in digital image processing, it can also be very effective conducted in a combination of optical techniques and digital processing. In this edge extraction method, a focused image of an object in a scene is first acquired. The image of the scene is then slightly defocused by changing the focal length of the camera. A real time subtraction operation is applied to subtract the defocused image from the previously acquired image. It produces a residual image that emphasizes abrupt intensity variations. An objective evaluation, called an edge index, is performed on the resulting image. The amount of defocusing is carefully adjusted according to this measurement so that a desired edge image is generated. Boundaries of objects can then be obtained by further enhancement of the edge image. Since this edge detection method is an optical-based process aided by digital processing, it is fast and relatively inexpensive.

Image representation with position-frequency localization

Abstract: A mathematical approach to image analysis and synthesis in the combined frequency-position space is presented. The formalism is based on the Zak (1967) transform, which provides one of the most fundamental tools for studies of nonstationary processes and images as such. Algorithms suitable for computation of Gabor (1946) expansion coefficients are presented and compared with regard to stability and computational complexity. >

Image information transmission system

Abstract: An image information transmission system according to the present invention is a system for transmitting image information. The system is arranged to receive a transmitted analog image signal and form digital image data by sampling the received analog image signal, then set a transmission-path characteristic by performing discrete Fourier transform operations on data which constitute a predetermined part of the formed digital image data, and then apply waveform equalization correction processing to the formed digital image data in accordance with the set transmission-path characteristic. Accordingly, the system is capable of transmitting image information accurately without being influenced by time base variations which occur on a transmission path.

Optimal multiresolution morphological image processing

Abstract: The problem of selecting the pyramid level for optimal morphological processing of an image with a selected structuring element is considered. Each level in the image pyramid is eroded by a structuring element and the residue computed. The residues for all pyramid levels are normalized and compared in order to determine the optimal image pyramid level. A method for residue normalization considering the fundamental morphological operation, erosion, is presented. An optimal structuring element can be determined at the selected pyramid level on the basis of minimal residues, providing as complete a representation of the image as possible. >

Local spectrum analysis of medical images

Abstract: A current goal in medical image processing is image segmentation and texture analysis. Although orthogonal transforms are interesting for image analysis they do not preserve spatial localization. In this paper we propose and compare some tools for local spectrum analysis. The first uses an evolutive windowed Fourier or Cosine Transform while the second is obtained via the 2D Wigner Distribution. Both of these transforms result in a collection of 2D spectra. In order to make the comparison easier we extract some parameters from each local spectrum. At last the first results obtained on a textural image and a medical image are presented.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Digital Image Processing in the Analysis of Astrometric Plates

Abstract: In this paper, we display an improvement to our process of semi-automatic measuring of astrometric plates, in which the photometric sensor is substituted by a CCD system of image getting and digitalization The advantages of this method are analyzed taking into account the possibilities of the image analysis in the space and frequency domain

Image classification by the Kittler-Young transform using a joint transform correlator

Abstract: This article will discuss a two-category image classification which has been performed on a joint transform correlator (JTC) by using the Kittler-Young transform. The property of optimally utilizing the class means and variances in the Kittler-Young transform has enabled a high space-bandwidth-product operation. The digitizing effect of the liquid crystal television has been utilized to increase the correlation peaks.

Apparatus for restoring original image from degraded image

Abstract: An image restoration apparatus comprises an image display device for displaying an image estimated as a nondegraded original image, a lens system for focusing the estimated image displayed on the image display device, an image input means for photographing an image focused by the lens system and for receiving the photographed image as image information, a comparing means for comparing the input image information received by the image input means with degraded image information prepared beforehand to obtain a difference therebetween, and a restoring means for performing restoration of an original image by changing the estimated image by using a random number on the basis of the difference calculated by the comparing means.

Knapsack formulation of image matching

Abstract: A technique is described to solve one of the problems encountered in an image analysis system, namely, region matching. The approach adopted is that of a medium level process. The information gathered during a segmentation stage is used to transform the original images into a collection of two-valued ones and a collection of gray-level histograms. Mathematical morphology is then used to define a measure of similarity on which the process is based. Correspondence are established between the segments according to a number of principles which are presented. A well behaved and efficient algorithm is proposed for the solution of the problem. >