Showing papers on "Channel (digital image) published in 1995"

Perceptual image quality based on a multiple channel HVS model

Abstract: We propose a new measure of perceptual image quality based on a multiple channel human visual system (HVS) model for use in digital image compression. The model incorporates the HVS light sensitivity, spatial frequency and orientation sensitivity, and masking effects. The model is based on the concept of local band-limited contrast (LBC) in oriented spatial frequency bands. This concept leads to a simple masking function. The model has the flexibility to account for the changes in frequency sensitivity as a function of local luminance and is consistent with masking experiments using gratings and edges. Numerical scaling experiments with a test panel and a set a test images that were coded using different coding algorithms showed that the proposed measure correlates better with perceptual image quality than the conventional SNR measure.

Automated thresholding of active lavas using AVHRR data

Abstract: An automated algorithm for thresholding hot pixels in AVHRR data is presented. The algorithm, applied to cloud-free sub-images of channel 3 minus channel 4 brightness temperature, compares each target pixel with its immediate background and then compares this difference with the natural variation in the surrounding region. Application to images of Mount Etna identified thermally anomalous pixels containing active lava or vents.

Sensor assembly providing gray scale and color for an optical image scanner

Abstract: A sensor assembly and an optical image color scanner using the sensor assembly. The sensor assembly is of the type having three separate rows of optical sensors. Two of the three sensor rows have color filters and one is unfiltered (receptive to white light). For gray scale scanning, only the unfiltered (white) sensor row is used, thereby maximizing the speed of gray scale scanning. For color scanning, three color values are computed as a linear transformation of values from the two filtered and one unfiltered values. The linear transformation may be as simple as subtracting signals from the two filtered sensor rows from the signal from the unfiltered (white) sensor row. For color scanning, memory buffers are required for two of the three sensor output signals. For highest accuracy in color scanning, the exposure time for the white sensor row is reduced relative to the exposure time for the two filtered sensor rows. An optional white channel bandpass filter (passing all wavelengths within the human visual range and rejecting wavelengths outside the human visual range) provides improved accuracy if the light source has significant wavelengths outside the human visual range.

Motion estimation using half-pixel refinement of frame and field vectors

Abstract: Method and corresponding circuit for estimating motion between pictures composed of interlaced fields. Conventionally, such a circuit comprises a channel for searching for the optimum frame vector, which channel is autonomous with respect to that for searching for the optimum field vectors. In accordance with the invention, the channel for searching for the optimum field vectors is unchanged, but for searching for the optimum frame vector the channel comprises two branches which are no longer autonomous but are arranged at the respective output of each sub-stage for searching for the field vector of the channel with a view to determining an approximation of the motion vector which is sufficient for the searched estimation.

Color encoding for polychromatic single-channel optical pattern recognition.

Abstract: The common multichannel system for recognizing colored images is replaced by a color-encoded single-channel system. Amethod inspired by the Munsell color system is used for encoding the different colors as phase and amplitude functions. It is shown that for many practical cases the phase information part of the color code is sufficient for obtaining good results. An implementation based on a liquid-crystal television panel that works in a phase-modulation mode is suggested. Computer simulations that demonstrate the capabilities of the suggested method are given as well as a comparison with previously published multichannel performance.

Karaoke control system for a plurality of karaoke devices

Abstract: When images of the image genre most suitable for the selected song are being reproduced (Yes in S14), the karaoke terminal picks up those image data from a channel over which they are transmitted. If images of that image genre are not being reproduced (No in S14), when the number of players presently playing is less than four (No in S19), a player that is not presently playing starts playing a video disk to reproduce images of that image genre in S20. When the number of players presently playing is equal to or greater than four, according to the image genre D and/or H reproducing status, a player that is not presently playing starts playing a video disk to reproduce images of image genre D or H that includes or is common to the most suitable image genre.

Electronic image pick up apparatus employing a comparison technique for reducing the effect of noise on the image

Abstract: An electronic image pickup apparatus comprising a focal plane shutter for controlling reception or cut-off of the light from an object, a CMD, image pickup device as a MOS-type internal amplification sensor, RGB channel process circuits for processing RGB outputs from the CMD, and a system controller for controlling the entire apparatus. The focal plane shutter lets in the light from the object to photograph for exposure. The resulting image data is temporarily stored in a memory. With no light from the object projected onto the CMD, a dark exposure is performed for the same time as the exposure to extract a signal corresponding to dark current. Reading the image data from the memory and reading the data at the dark exposure are performed at the same time. The dark current component is removed by subtracting the dark exposure data from the image data.

Stochastic attribute grammar model of document production and its use in document image decoding

Abstract: Document image decoding (DID) refers to the process of document recognition within a communication theory framework. In this framework, a logical document structure is a message communicated by encoding the structure as an ideal image, transmitting the ideal image through a noisy channel, and decoding the degraded image into a logical structure as close to the original message as possible, on average. Thus document image decoding is document image recognition where the recognizer performs optimal reconstruction by explicitly modeling the source of logical structures, the encoding procedure, and the channel noise. In previous work, we modeled the source and encoder using probabilistic finite-state automata and transducers. In this paper, we generalize the source and encoder models using context-free attribute grammars. We employ these models in a document image decoder that uses a dynamic programming algorithm to minimize the probability of error between original and reconstructed structures. The dynamic programming algorithm is a generalization of the Cocke-Younger-Kasami parsing algorithm.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Circuit for improving the stereo image separation of a stereo signal

Abstract: By using special frequency response manipulation in the difference channel of a stereo signal, the stereo image will appear to extend beyond the actual placement of the loudspeakers This is accomplished by shaping the difference channel response to simulate the response one would be subjected to if the sources were physically moved to the virtual positions The circuit includes a summing and high frequency equalization circuit to which the left and right stereo signals are applied, and a difference forming and human ear equalization circuit also to which the left and right stereo signals are applied The outputs from these circuits are cross-coupled to form left and right channel outputs

Raw SAR data compression using vector quantization

Abstract: Synthetic Aperture Radar (SAR) is a day/night and all-weather active imaging system. which can record images with a fine spatial resolution independent of the sensor altitude. All these characteristics make the SAR a valuable instrument for Earth observation. However, computer system technology does not currently enable spaceborne processing and storage of the great amount of data required to synthesize an image. Vector quantization is a lossy numerical method for signal compression. This method can be implemented aboard remote systems and is designed to reduce the bit stream of transmission over a noiseless channel. Analysis and prospects for this compression algorithm, applied on raw SAR data, are presented.

Picture storage device separates luminance signal into even number and odd number data and separates two channel color signal into former half pixels and latter half pixels

Abstract: A picture storage device conveniently employed in conjunction with an electronic still camera or a video camera has an input data converting unit for separating luminance signals of input color picture data having a non-interlaced data format with the sampling rate of the luminance signals and two-route color signals of 4:2:0 into a data string of even-numbered pixels and a data string of odd-numbered pixels, separating the two-route color signals of the color picture data into a data string of the former half pixels and a data string of the latter half pixels, and distributing and re-arraying the separated data, a storage unit having a storage capacity of at least one frame and adapted for storing data in a data re-arraying sequence by the input converting unit, a display data converting unit for converting the data stored in the storage unit into picture-displaying data, and a controller for controlling the input converting unit into synchronization with data writing in the storage unit.

Method and apparatus for non-blinking displaying of grayscale image on monochrome LCD screen

Abstract: Disclosed is a method and apparatus for displaying (simulating) grayscale images on a monochrome LCD screen particularly with an objective of providing a comfortable displaying effect that presents no blinking of dots to the user's eyes. In the method, the grayscale image is divided into a sequence of pages of image data each having an array of dots equal to the resolution of the grayscale image such that each pixel on the grayscale image corresponds to a sequence of dots respectively on the corresponding location on the N-1 pages of image data. Black and white colors are assigned to the dots in accordance with a color assignment algorithm that allows the black and white colors to be evenly distributed. When the pages are displayed in succession at a fast rate on the monochrome screen to simulate grayscale image, the black dots or white dots appear evenly on each page so that blinking of dots would not present to the user's eyes.

Color inspection system

Abstract: An apparatus and method to control a video camera for the acquisition of a color image under varying image capture conditions includes a video camera having a red, green and blue output. The video camera is provided with a controllable iris aperture, a controllable overall RGB signal gain, independently controllable RGB signal channel gains and a controllable RGB signal channel balance. The controllable parameters are controlled by a control unit. The control unit generates signals from an image signal received from the video camera. The signals are used to correct the controllable parameters to improve camera image capture performance.

Image interpolator for an image display system

Abstract: An apparatus for interpolating an image from a plural number of image values for a display having an array of display pixels more numerous than the number of images. The apparatus includes a generating device, a designating device, and first and second applying devices. The generating device generates image signals based on image data representing an image of a living body and for designating an array of pixels based on the image signals. The designating devices designates as primary image pixels a limited plurality of display pixels within the array of pixels. The first applying device applies the image values each to a respective one or more of the primary image pixels. The second applying device applies the image values to the remaining display pixels of the array according to an allocation pattern associating each remaining display pixels with a particular one of the primary image pixels, such that the distribution of display pixels associated with each primary image pixel is, at a distance from the respective primary image pixel, increasingly sporadic with increasing distance from the respective primary image pixel.

Apparatus for encoding an image signal having a still object using an image warping technique

Abstract: An apparatus for encoding an image signal having a still object generates a first encoded image signal by encoding a contour signal detected at a first encoding channel, the contour signal providing boundary information for tracing an object boundary in a video frame. The video frame is divided into a plurality of processing blocks with a predetermined identical size. Each of the processing blocks selectively coupled to an image reconstruction device or a second encoding channel in response to a control signal indicating whether or not a part of the object boundary exists in each of the processing blocks. The image reconstruction device generates reconstructed processing blocks based on the processing blocks applied thereto.

Digital braodcasting television receiver

Abstract: PROBLEM TO BE SOLVED: To reduce the mental burden of a user that is caused by the channel switching duration. SOLUTION: A dynamic image processing part 113 produces plural sheets of images where a dynamic image becomes gradually large after a channel is switched, and a static image processing part 114 produces plural sheets of images where a static image becomes gradually small after the channel is switched. The outputs of both parts 113 and 114 and the output of an MPEG decoder 17 are supplied to the switch circuits 115 and 116. When the channel is switched, a controller circuit 18 controls both circuits 115 and 116 to successively project the outputs of the parts 113 and 114 and the decoder 17 on a CRT 119. Thus the static image becomes gradually small before the channel switching, the dynamic image of a desired channel becomes gradually large, and finally the image of a desired channel is projected on the CRT 119. COPYRIGHT: (C)1997,JPO

Particle measuring method and particle detecting sensor thereof

Abstract: The method suitable for automatic measurement of solid particles in liquid uses liquid pipe with long slit to increase cross section of liquid channel, so avoiding the channel being blocked by big particles. A CCD camera with electronic shutter is used for the measurement by means of video image, so having high precision and analysis flexibility. The image may also be recorded with videocorder for later analysis.

An image restoration system for a single-CCD color camcorder

Abstract: A new image restoration system for improving the image of a single-CCD color camcorder is proposed. The single-CCD color camcorder reconstructs red, green, and blue color channels from a color filter array followed by a CCD. During this reconstruction process, color cross-talk among channels (interchannel distortion) and periodically space-varying blur (intrachannel distortion) occur. The proposed restoration system reduces interchannel distortion, and then, restores each color channel by removing the corresponding intrachannel distortion. Experimental results show that the proposed system provides the improved images in both objective and subjecture senses. The proposed system can be implemented by using a finite impulse response (FIR) filter structure, which is particularly suitable for real-time image processing. >

Electronic imaging: a tool for the reconstruction of faded color photographs and color movies

Abstract: A method to restore faded color materials by digital image processing is ,2 The algorithms used for the re-construction are based on photographic experiments, i.e., on accelerated fading tests of various photographic materials.The densities of the original and the faded materials were measured. Based on this data, a mathematical model for fadingcan be described by a linear equation.The faded image is digitized using a scanner of high spatial and photometric resolution. For good spectral resolution,channel separations are done with narrow-band interference filters. The original colors are reconstructed by applying theinverse of the fading equation. The corrected image is exposed with a high-resolution film recorder on color film. The method shows good results for color slides, prints, and 16mm movies. Keywords: photography, image processing, restoration, motion picture film, permanence, color reproduction, eigenval-ues, principal component analysis, dye spectra1. INTRODUCTIONThe unique importance of photographic and motion picture images for the research relating to the history of civilizationis due to the fact that they often are the only authentic visual sources for certain subjects or periods of time. In most cases,the storage of these pictures is unsuitable, and many of them are in poor condition. Photographic film and paper are unsta-ble media and deteriorate over time.Of all photographic materials, color emulsions show the quickest degradation behavior. The dyes of common chro-mogenic processes are chemically rather unstable. Both the thermodynamic and the photochemical stability are low, andthe expected life span of color materials is in the order of years to decades. Improper processing and/or environmental in-fluences such as light, chemical agents, heat, humidity and storage conditions affect images by fading the dyes and/orproducing stain. Photographic emulsions also contain other components such as sensitizers, color couplers, and stabilizerswhich can alter the image appearance with time. Decreasing humidity helps to prevent fading to a certain extent, but theonly reliable method to keep color photographic materials for a long time is in dark storage at low temperature and lowhumidity. In the case of unsuitable storage conditions where photographs and movies have faded, the question of restora-tion becomes evident. Restoration of faded materials by chemical processes, principally possible for black-and-white pho-tography, is not possible for color photography because dye fading is an irreversible process.Methods to restore images through photographic copying have been developed.35 However, these methods are slow,need skilled operators, and work only if fading has not proceeded too far.This paper presents an approach to reconstruct faded color photographic materials by digital image processing. Notethat digital reconstruction is not a restoration in the classical sense. In black-and-white photography, the image is usuallyrestored and conserved on its original support. In the case of color images, a restoration of the original is not possible be-cause the original dyes cannot be reconstructed. Therefore, the aim of the reconstruction is to restore the appearance ofthe original colors as accurately as possible on a new material.

Computer laminagraphy imaging device

Abstract: PURPOSE: To reduce a streak artifact of an X-ray tomographic image without deteriorating resolution of the image by making an error spectrum from obtained X-ray scanning data of respective views and projection data of corresponding respective groups, and reconstituting the image by substracting this from data of the corresponding groups. CONSTITUTION: Scanning data of respective views is supplied to input 50, and is processed by a correcting and calibrating part 51, and various well-known errors such as a variation in gain of a detector and a channel are corrected. In the next place, corrected data generates a projection profile P to express a quantity of an attenuating substance in a patient running along an X-ray beam related to respective detecting elements by taking a negative number of its logarithm by a logarithm adjusting part 52. An adaptive filter makes an error vector θ. The error vector θ is subtracted from a corresponding attenuation value in the projection profile P at an adding point 53. Next, the corrected and adaptively filtered projection profile P is impressed on a reconstituting unit 54, and a slice image 55 is made.

Teletext multiplex decoder built-in type multi-screen display television receiver

Abstract: PROBLEM TO BE SOLVED: To improve the utilizing efficiency of an image memory and a companding circuit considerably especially by providing a control means storing image data demodulated by a data broadcast reception and demodulation means and reading and displaying the stored content depending on an operation command. SOLUTION: A TV signal received by a tuner 121 is given to a selector 123, and a video signal is compressed by an image processing section 124. Thus, an image memory and a memory control circuit are integrated in the image processing section 124. Thus, a remote operation device 150 is operated to store teletext multiplex broadcast data or data of a supplement program tentatively via a system controller 151. That is, in the program search function or the program menu generating function, a reception channel of the tuner 121 is selected one after another by remote control and each pattern of the selected channel is compressed and stored in the image memory sequentially and plural image patterns are displayed on the same screen by reading the image memory.

X-ray ct image processing system and method therefor

Abstract: PURPOSE:To dispense with the troublesome preparation work for inputting and others, obtain the correct CT image of a measured object combined with members of different materials, and correctly extract the boundary. CONSTITUTION:This X-ray CT image processing system is provided with a fan beam X-ray source 1 radiating fan beam X-rays to a measured object 2 made of two members of different materials, a multi-channel linear sensor 3 rotatably arranged to face the fan beam X-ray source 1 and detecting the transmitted X-rays transmitting the measured object 2, and an image processing device 4 differentiating and binarizing the interference portion between these different materials of the CT image data determined by the output level of each channel of the linear sensor 3 via the blur distribution of one member and extracting the CT image and boundary.

A correlation based cloud-detection algorithm combined with an examination of some split-window assumptions

Abstract: Twenty-six daytime NOAA-11 AVHRR images covering the Danish waters are analysed together with 99 cloud-free bulk temperature measurements. The images are cloud screened with a cloud-detection algorithm, which in excess of the usual threshold and variation tests consists of: a min_max-routine which among suspicious pixels points out the cloud contaminated pixels, and a separation of cloud pixels from cold water pixels by means of the correlation coefficient between the channel 4 brightness temperature and the channel 4-channel 5 brightness temperature. In the cloud screened images, the channel 4-channel 5 brightness temperatures do not increase with the satellite zenith angle and do not seem to carry any significant information about the true sea surface temperature (SST). Local meteorological and oceanographic effects are believed to be more important than the channel 4-channel 5 brightness temperatures.

Method and equipment for detecting position and featurer amount

Abstract: PURPOSE:To detect the position and feature amount of an object having periodic pattern, e.g. the groove in a channel plate being employed in an ink jet head, highly accurately. CONSTITUTION:A CCD line sensor takes in the one-dimensional image signal in y-direction (periodic direction) from a periodic pattern formed on an object 7. The image signal is subjected to Fourier transform based on the number of reference pixels corresponding to one period of the pattern P and the position is detected based on a phase angle obtained through Fourier transform. The object 7 is shifted in the periodic direction and an average positional shift of the pattern P is detected, as a feature amount, from the difference of phase angle and an actual amount of movement. The object 7 is then shifted in x- direction and the rotational amount of the object is detected from the difference of phase angle. Number of reference pixels is varied for a plurality of objects having periodic pattern and the one-dimensional image signal is sequentially subjected to Fourier transform. The position is then detected based on the phase angle for such number of pixels as the Fourier spectrum is maximized.

Colour inspection system

Abstract: The disclosure relates to a colour inspection method and apparatus, and to a method of control of a video camera for the acquisition of a colour image under varying image capture conditions. A video camera (1) has a red, green and blue output (RGB) and is provided with a controllable iris aperture, a controllable overall RGB signal gain, independently controllable RGB signal channel gains, and a controllable RGB signal channel balance. The controllable parameters are controlled by a control unit (3) in the form of a personal computer having an image capture board (4). The personal computer generates signals from an image signal received from the video camera, the signals being used to correct the controllable parameters to improve camera image capture performance. The disclosure finds application in quality control systems, for example for controlling the paint colour of products on a production line.

Curvature Estimation with a DCA Neural Network

Abstract: Curvature has been identified as an important feature to reconstruct properties like object shape or relative depth from two-dimensional gray scale images [6, 9]. This coincides with the assumption that curvature is processed by a separate channel in human early vision, just like contours or contrast [23, 2, 3]. The process of early vision is assumed to be divided into vision modules [15] that are evaluated independently in almost completely separate pathways [21, 5, 10]. This motivates to study how artificial neural networks can be used to mimic the operation of some of these putative modules. In this contribution we investigate to what extent curvature information can be extracted from an image, only on the basis of the gray scale pixel information. The paper shows that a neural network based on local linear maps LLM can be trained to estimate the local amount and orientation of curvature from only a small patch of grayscale pixel images. The accuracy of this estimation depends on the complexity of the surfaces. Using a recently developed approach of cascaded LLM-networks (DCA), we demonstrate that the performance that can be obtained with a standard LLM-net can be considerably improved.

Using genetic algorithms to improve interpretation of satellite data

Abstract: We investigated a problem involving the automatic classification of satellite pixels. Each image is a 512 by 512 matrix of pixels, each of which consists of 4 channel values. The classification of these pixels into one of five classes is ordinarily an arduous process. A variety of search algorithms have been created to solve optimization problems. One of these search algorithms, genetic algorithms, has been developed from the concepts of Darwinian evolution and natural selection. They have several advantages over other search methodologies which are of use to this problem. They do not need expert knowledge, they evaluate a large number of potential solutions quickly and nearly simultaneously, and they are able to identify near optimal solutions while searching for better answers. The method employed uses genetic algorithms to identify a good representative are chosen, classification category. Once the representatives are chosen, classification of pixels in similar images is easily automated. The results indicate that genetic algorithms can be used to classify pixels from satellite images quickly and with a good degree of reliability.

Image sequence processor for personal computer

Abstract: It is sought to display a pluralities of full motion image sequences together with personal computer texts, graphics, etc. on a personal computer display. NTSC signal converters 100 (10A, 10B, . . .) each provided for each video input channel each send out color digital brightness signals of a contracted image size, obtained through conversion of a video input signal. These signals are written in and read out from R, G and B color signal memories 20 under control of a command from a write/read controller 23. The read-out color digital brightness signals are converted in a digital-to-analog converter 30 into analog signals. An overlay controller 31 overleys these analog signals over R, G and B analog inputs from a personal computer under control of a display position determining signal supplied from a CPU via a personal computer bus 41, thus producing R, G and B analog outputs which are displayed as image sequence on the same personal computer display. For the display of a plurality of image sequences, the NTSC signal converter and color signal memories (20e, 20g and 20b) are provided for each video input channel.

Device of video picture signal transmission and reception

Abstract: PURPOSE: To provide a device and a method for selecting and sending an encoded block of video information at various channel rates. CONSTITUTION: This device selects and sends an encoded block of this signal at various channel rates based on the corresponding part position of a video image that is shown by the encoded block. Each encoded block is designated to an image type which decides its sending channel rate. The image type is associated with the space position of a video image as the encoded block in a 1st area of the video image is a 1st image type and that the encoded block in a 2nd area is a 2nd image type. Generally, a data block that shows the central part of the video image is sent in a channel rate where sensitivity to noise and other deterioration is low, and the central part is receivable in a broadcast edge area.

Algorithms for signal and image recovery

Abstract: This dissertation presents some signal recovery algorithms which were developed based on certain nonlinear optimization principles. The specific problems of interest are image enhancement, blind image restoration, and blind channel equalization. A systematic method is established for analyzing the behavior of anisotropic diffusion, a recent tool for image enhancement, by posing the anisotropic diffusion equation as resulting from a certain optimization problem. Principles for designing well-behaved anisotropic diffusion schemes are established based on the analysis and an orthogonal decomposition of the diffusion equation. A class of well-behaved anisotropic schemes is developed. Space-adaptive regularization methods for blind restoration of shift-invariantly degraded images are developed by posing the problem as minimizing a cost function, and alternating minimization is proposed to minimize the cost function efficiently. Well-behaved anisotropic diffusion is incorporated into this method to arrive at orientation-selective regularization so that ringing artifacts in the restored images are reduced. This method is then extended to restore shift-variantly blurred images. Alternating minimization is proposed as a general framework to accomplish joint data estimation and channel identification. Under this framework, a cost function is minimized through alternating two minimization steps which turn out to be data estimation and channel identification. The algorithms derived from this scheme are guaranteed to converge. A simple blind equalization algorithm is derived based on the steepest descent method. This algorithm degenerates into a simple sequence estimator if the channel response is known.