Showing papers on "Channel (digital image) published in 1999"

Modified fuzzy c-mean in medical image segmentation

Abstract: This paper describes the application of fuzzy set theory in medical imaging, namely the segmentation of brain images. We propose a fully automatic technique to obtain image clusters. A modified fuzzy c-mean (FCM) classification algorithm is used to provide a fuzzy partition. Our new method, inspired from the Markov random field (MRF), is less sensitive to noise as it filters the image while clustering it, and the filter parameters are enhanced in each iteration by the clustering process. We applied the new method on a noisy CT scan and on a single channel MRI scan. We recommend using a methodology of over segmentation to the textured MRI scan and a user guided-interface to obtain the final clusters. One of the applications of this technique is TBI recovery prediction in which it is important to consider the partial volume. It is shown that the system stabilizes after a number of iterations with the membership value of the region contours reflecting the partial volume value. The final stage of the process is devoted to decision making or the defuzzification process.

Multiple description image coding using signal decomposition and reconstruction based on lapped orthogonal transforms

Abstract: This paper considers the use of multiple description coding (MDC) for image transmission in communication systems where long burst errors and sometimes complete channel failures are inevitable. A general framework for MDC is proposed, which uses nonhierarchical signal decomposition at the encoder and image reconstruction at the decoder. A realization of this framework using lapped orthogonal transforms (LOTs) is developed. In the encoder, the bitstream generated by a conventional LOT-based image coder is decomposed so that each description consists of a subsampled set of the coded LOT coefficient blocks. In the decoder, instead of using the inverse LOT directly, a novel image reconstruction technique is employed, which makes use of the constraints between adjacent LOT coefficient blocks and the smoothness property of common image signals. To guarantee a satisfactory reconstruction quality, the transform should introduce a desired amount of correlation among adjacent LOT coefficient blocks. The tradeoff between coding efficiency and reconstruction quality obtainable by using different LOT bases is investigated.

Exploiting the cross-correlation of RGB-channels for robust watermarking of color images

Abstract: In the last few years, digital watermarking has been proposed as a solution to the problem of copyright protection of multimedia data against unauthorized uses. In the field of image watermarking, research has been mainly focused on grey-scale image watermarking, whereas the extension to the color case is usually accomplished by marking the image luminance, or by processing each color channel separately. In this paper, a DCT domain technique expressly devised for watermarking of color images is presented, which exploits the characteristics of the human visual system and the correlation between the RGB image channels. Experimental results are presented to demonstrate the validity of the new approach with respect to algorithms operating on image luminance only.

Capacity of the watermark channel: how many bits can be hidden within a digital image?

Abstract: An evaluation of the number of bits that can be hidden within an image by means of frequency-domain watermarking is given. Watermarking is assumed to consist in the modification of a set of full-frame DCT (DFT) coefficients. The amount of modification each coefficient undergoes is proportional to the magnitude of the coefficient itself, so that an additive- multiplicative embedding rule results. The watermark-channel is modeled by letting the watermark be the signal and the image coefficients the noise introduced by the channel. To derive the capacity of each coefficient, the input (i.e. the watermark) and the output (i.e. the watermarked coefficients) of the channel are quantized, thus leading to a discrete- input, discrete-output model. Capacity is evaluated by computing the channel transition matrix and by maximizing the mutual input/output information. Though the results we obtained do not take into account attacks, they represent a useful indication about the amount of information that can be hidden within a single image.

Method and appratus for minimizing false image artifacts in a digitally controlled display monitor

Abstract: The invention is directed to improve visual effects on digital display devices (Fig. 7) that use time and space modulation methods to display grayscale values, by using a distributed line technique to provide grayscale capability. The grayscale display is illuminated by energizing pixels of a weighted grid of eight line addresses. There are N grid sets where N is the number of time slots allocated per frame time. The visual grayscale brightness of each pixel is determined by the selection of the grid sets and the time slot allocated for the grid sets. The bit value selection, grid set allocation, and time slots are chosen such that the grayscale values are scattered in time and space so that the perception of visual disturbances and other perceived artifacts are avoided.

Making saturated facial images useful again

Abstract: Saturation here refers to electronic saturation of the camera sensors which produces clipped colors, and not the purity of color as in the hue-saturation and value scale. Saturated images are routinely discarded in image analysis yet there are situations when they cannot be avoided. This paper proposes two strategies to recover color information in facial images taken under non-ideal conditions to make them useful for further processing. The first assumes that the skin is matte and that there are parts of the image which are not clipped. Ratios between R, G and B values of unclipped pixels belonging to the same parts of the image may then be used to compute for lost channel values. The second approach uses color eigenfaces computed from our physics-based face database obtained under different illuminants and camera calibration conditions. Skin color is recovered by transforming the first few eigenface coefficients towards ideal condition values. Excellent color recovery for clipped images is achieved when these two techniques are combined and used on face images captured under daylight illuminant with a camera white balanced for incandescent light.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Adjusting the contrast of a digital image with an adaptive recursive filter

Abstract: A method and structure for adjusting the contrast of a digital image includes inputting an image, dividing the image into a pedestal signal and a texture signal, applying a tone scale function to the pedestal signal to produce a modified pedestal signal, and adding the texture signal to the modified pedestal signal to produce a processed digital image channel. The dividing filters a pixel of the image using weighting that is dependent upon coefficients of neighboring pixels adjacent the pixel. The filtering blurs the pedestal signal such that flat areas of the image are blurred more that discontinuities in the image.

Color correction estimation for panoramic digital camera

Abstract: A method for correcting color in a system for creating a panoramic image from a plurality of images taken by a camera. The method comprising the steps of: receiving a color channel from at least a first image and a second image; creating an overlap portion between the first image and second image; and adjusting the color channel for the first image and for the second image in at least the overlap portion between the first image and the second image which is independent of motion estimation. In an alternate embodiment, a system and computer readable medium corresponding to the above method is described.

Spectrum estimating method of spectral reflectance of multi-band image and spectrum estimating system

Abstract: PROBLEM TO BE SOLVED: To provide a spectrum estimating method of a spectral reflectance of a multi-band image and a spectrum estimating system, capable of shortening a processing time for obtaining an estimated spectrum without reducing estimation accuracy of the spectrum effectively, when the multi-band image is photographed by using a variable wavelength filter and the spectrum of the spectral reflectance of a photographing object is estimated by using it. SOLUTION: In this estimating method, a conversion table in which a brightness value obtained by photographing a chart having a known reflectance is made to correspond to the reflectance in each channel of a multi-band image comprising plural original images, is formed beforehand, and the brightness value of the original images of the multi-band image obtained by photographing an object is converted into a reflectance by using the conversion table, to thereby estimate a spectrum of a spectral reflectance of the object. This spectrum estimating system of the spectral reflectance of the multi-band image by using the estimating method of the spectrum is also provided.

Single channel speech enhancement using principal component analysis and MDL subspace selection

Abstract: Keywords: LTS1 Reference LTS-CONF-1999-014 Record created on 2006-06-14, modified on 2016-08-08

Color capture, color management, and the problem of metamerism: does multispectral imaging offer the solution?

Abstract: Color management systems are being introduced worldwide to improve the color quality of digital image capture and device independent electronic color image reproduction. To be able to supply device independent color data at interfaces in imaging systems, device dependent color correction is required. The paper discusses concepts envisaged for color correction in image capturing devices with respect to fundamental requirements on color analysis. The common image capturing technology is based on the use of three color channels. Main points of the discussion are the shortcomings of this technology to analyze metameric colors correctly and the question if this will be an essential point for future imaging technology. Further parts of the paper cover the alternative multispectral technology. Multispectral cameras delivering the complete spectrum of color stimuli of each pixel of an image are available in the laboratory. This technology offers s solution to the problem of metameric color analysis and offers flexibility to match different illuminants as well, yet, the amount of additional effort is large. The paper summarizes studies and ideas on multispectral color technology and on how this technology might be introduced in future imaging and color management systems.

Authorizing the printing of digital images

Abstract: A method of authorizing the making of images on a receiver such as postage stamps by a receiving agency includes electronically transmitting a digital image file over a channel to the receiving agency and the digital image file includes at least one digital image and authorization information for making images on a receiver. The method further includes receiving the digital image file at the receiving agency, displaying at least one received digital image and examining the displayed digital image to determine whether its contents are acceptable for making images and examining the authorization information and printing at a designated location accepted digital images on a receiver corresponding to the transmitted digital image when the authorization information is approved.

Facilitating the compositing of video images

Abstract: Image data taking the form of a plurality of image pixels is processed. A three dimensional representation of color-space is displayed and the color of pixels within the processed image are analysed such that said analysed pixels are displayed at color related positions within the displayed color-space.

Method for determining color of illuminant and apparatus therefor

Abstract: A method for determining the color of an illuminant and an apparatus therefor are provided. The method for determining the color of the illuminant according to the present invention includes the steps of obtaining an RGB mean vector value by selecting an arbitrary image and calculating a mean value in each RGB channel with respect to the image, defining a predetermined coefficient f which is a positive integer larger than 1 and estimating a value obtained by multiplying f by the RGB mean vector value as temporary color of the illuminant with respect to the selected image, estimating the illuminant color closest to the temporarily estimated illuminant color temperature on the day light locus as an illuminant color temperature, setting a value obtained by multiplying k by the estimated color of the illuminant as a self luminous threshold value in order to establish a self luminous area using a human visual characteristic wherein k is a predetermined coefficient which is a positive integer larger than 1, generating an image from which the self luminous threshold value is removed by removing the self luminous area having the RGB value exceeding the self luminous threshold value, and calculating the color of an illuminant from the uv chrominance value of the image from which the self luminous area is removed and outputting the illuminant color. It is possible to stably and effectively extract information of an illuminant by selectively excluding a self luminous area from a visually sensed image in the method for detecting the illuminant color according to the present invention.

Comparative analysis of color architectures for image sensors

Abstract: We have developed a software simulator to create physical models of a scene, compute camera responses, render the camera images and to measure the perceptual color errors between the scene and rendered imags. The simulator can be used to measure color reproduction errors and analyze the contributions of different sources to the error. We compare three color architectures for digital cameras: (a) a sensor array containing three interleaved color mosaics, (b) an architecture using dichroic prisms to create three spatially separated copies of the image, (c) a single sensor array coupled with a time-varying color filter measuring three images sequentially in time. Here, we analyze the color accuracy of several exposure control methods applied to these architectures. The first exposure control algorithm simply stops image acquisition when one channel reaches saturation. In a second scheme, we determine the optimal exposure time for each color channel separately, resulting in a longer total exposure time. In a third scheme we restrict the total exposure duration to that of the first scheme, but we preserve the optimum ratio between color channels. Simulator analyses measure the color reproduction quality of these different exposure control methods as a function of illumination taking into account photon and sensor noise, quantization and color conversion errors.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Method and apparatus for re-classifying color image pixels classified by single channel segmentation

Abstract: A method and apparatus are provided for use in single channel segmentation of color images for reclassifying pixels which were inappropriately classified as belonging to a “black” or “white” class. The apparatus includes a re-classification circuit receiving first classification data generated by a single channel segmentation circuit operative to classify pixels of a multi-color channel input image. The re-classification circuit selectively re-classifies pixels that were previously classified by the single channel segmentation circuit into an “other” segmentation class based on a comparison of classification data associated with the pixels relative to a set of predefined classification data types. Particularly, the re-classification circuit reclassifies selected ones of the pixels into the “other” segmentation class when first classification data generated by the single channel segmentation circuit labels the pixels as a “white” or “black” data type.

Method of using photoalbum templates

Abstract: Templates having sets of frame, channel, and possibly “dot” cutouts, and methods for using such templates for shaping and laying out photographs on a page to create a decorative pattern

Video distributor, video receiver, video distribution system and video distribution method

Abstract: PROBLEM TO BE SOLVED: To enable many recipients to view different video images respectively while remotely operating a same camera individually and virtually by using the video images of plural visual fields photographed by one set of the camera SOLUTION: A camera 3 photographs video images of plural visual fields while switching the visual fields to plural steps for a fixed period, records them respectively to prescribed addresses of a memory of a video server 2 and the video server 2 applies the video image transmission technology of a multi-cast method to assign each of the video images of the plural visual fields to respective broadcast channels and to upload them to an Internet 5 On the other hand, a terminal 6 of a party desiring to receive a video image uploads a reception request designating a broadcast channel through which a video image of a specific visual field is provided to the Internet 5 Then, a router designates a channel providing the video image on request of the reception among the respective video images in the plural broadcast channels and downloads the designated video image to the terminal 6 which the video image is displayed on a display device

Region growing based noise reduction method for digital images

Abstract: A method for removing noise from a pixel of a digital image channel includes the steps of: storing an original value of the pixel of interest and using the value of the pixel of interest and neighboring contiguous pixels to determine a variable shape neighborhood region of cleaning pixels. The method further includes using the neighborhood region of cleaning pixels and the value of the pixel of interest to replace the original value of the pixel of interest with a noise cleaned pixel value.

Hierarchical progressive image coding controlled by a region based approach

Abstract: This paper presents a progressive image coding technique in which a rough preview image is enhanced with the zerotree encoding of the residual image in the wavelet domain The preview image is achieved with a region based approach that gives a basic description of the scene with a very high compression ratio As a second stage, the residual between the original image and the preview is decomposed using a wavelet transform, and it is encoded for a progressive transmission The wavelet coefficients are selected from the coarsest to the finest level of resolution, using a mask obtained from the image preview Such a mask sets the importance of the coefficients on the basis of their distance from the contours of the regions of the preview A modified zerotree approach is used to progressively encode the weighted coefficients until significant texture is introduced in the image and the required quality is achieved Moreover, if an image with very good quality is required, the resulting reconstruction error is encoded by means of vector quantization and transmitted over the channel The proposed method is compared to progressive JPEG, and it gives similar results at low compression ratios and far better results at higher ones

Portable videomicroscopic observation of suspended particles in gas or liquid stream

Abstract: Flow in the channel ahead of the observation point, passes a sensor zone where particles are detected optically or electrically. The detector signal triggers circuitry causing image recording by the video microscope. A delay circuit is incorporated, so that the image is not taken until the particle is located in the imaging frame. An Independent claim is included for the apparatus implementing the method. The detector is a miniature condenser (7) ahead of the imaging microscope (13). On particle (5) arrival between its electrodes, resulting capacity difference produces a measurable signal pulse (8) in the condenser circuit. Preferred Features: Particle detection takes place at the focus of a light source in the flow channel. Here a flash of light is caused by particle entry into the intensely illuminated zone. A sensitive photodetector, e.g. a photomultiplier, registers and signals the event. A CCD camera processes the image signal. This is an intelligent camera, analyzing the image and characterizing the particles and their calculated parameters. No external computer is required. The result is a compact, portable and fully autonomous particle measurement apparatus. Imaging takes place on a standard video monitor, or on an integral small screen of the camera. Results of numerical analysis from the intelligent camera, are displayed on a standard monitor or a miniaturized video monitor. They can also be made available as analog signal outputs. Digitized images may also be input to external computers for further analysis and documentation. The intelligent camera can be computer controlled, from remote locations.

Coder for stereoscopic moving image

Abstract: PROBLEM TO BE SOLVED: To provide the coder for a stereoscopic moving image that realizes a higher coding efficiency that that of a conventional technology by keeping image quality of a left image higher than that of a right image at all times even when fluctuation is generated in a characteristic of a scene of a picture. SOLUTION: Distributions T1, T2 of an object bit rate for a basic channel (left) and an extended channel (right) are set in advance to an assigned bit distribution setting section 26, and virtual buffer occupancy amount calculation sections 25, 47 calculate a virtual buffer occupancy amount (d) based on a produced bit number (s) and the distributions T1, T2. Quantizers 14, 34 obtain a quantization step size so that a quantization step size of the basic channel is smaller than the step size of the extended channel by a prescribed amount based on macro block information from a macro block information storage table 44, activity and the virtual buffer occupancy amount (d) and calculate the quantization level by dividing orthogonal transform coefficients with the quantization step size.

Method and apparatus for single channel color image segmentation using local context based adaptive weighting

Abstract: A method and apparatus for single channel color image segmentation using local context based adaptive weighting is provided. The varying weightings of the projection vector are determined as a function of local input image activity context. A Sobel operator is used to calculate the input image activity. A binary map is created for each color channel and is adapted to store binary markers indicative of local activity levels on a per pixel basis. The binary maps are low pass filtered and then normalized to generate a context based adaptive weighting vector for use in single color segmentation of a multi-channel color image signal.

Bayesian image restoration using a wavelet-based subband decomposition

Abstract: The subband decomposition of a single channel image restoration problem is examined. The decomposition is carried out in the image model (prior model) in order to take into account the frequency activity of each band of the original image. The hyperparameters associated with each band together with the original image are rigorously estimated within the Bayesian framework. Finally, the proposed method is tested and compared with other methods on real images.

Device and method for inspecting fine defect and positional deviation calculating circuit

Abstract: PROBLEM TO BE SOLVED: To detect an image with small pixel dimensions to detect a fine defect on an object substrate to be inspected having small patterns, to fast perform aligning process of a wide range because the aligning range becomes equivalently wide at that time and also to make an image processing circuit fast and also small-sized. SOLUTION: An image of pixel dimensions of =±4 pixels. Also, a fast and small image processing part 13 is realized by mounting image processing circuits 10 and 11 composed of an LSI capable of (k) channel processing on one substrate 15.

Method and apparatus for physical image based inspection system

Abstract: A method is described that involves accepting a mask design file input and then simulating the inspection of a mask through an optical channel. The mask design file has patterns. The optical channel corresponds to a mask inspection tool optical channel. The mask is patterned according to the mask design file patterns.

Image correction method, image correction device, and recording medium

Abstract: Color correction and density correction are performed on an image without changing the gradation of an image. When color correction and density correction are performed on image data whose values for each R, G, B component color (each channel) of each pixel are coded according to predetermined characteristics, the image data is sampled and correction values are calculated. The image data is then converted ( 104 ) to image receptor reflectivity data (r, g, b) (converted to values whose relationship with the light intensity values of each pixel is linear). The image data is then further converted to tristimulus values data (X, Y, Z) and color correction and density correction are carried out. The tristimulus values data after correction (X′, Y′, Z′) is then converted to image receptor reflectivity data (r′, g′, b′) and then to image data (R′, G′, B′). Accordingly, color and density corrected image data can be obtained without the gradation of the image being changed.

Image display system, image display method and remote control system

Abstract: PROBLEM TO BE SOLVED: To provide a convenient channel for monitoring the other channel and to present the output of plural display devices without hiding the upper part of images displayed on an image screen. SOLUTION: In this image display system 150 capable of simultaneously displaying two different images, one image is displayed at an image display device 114 and the other image is displayed at a video remote control 170. A docking station provided with an image processor 172 is connected to a TV and a video device and sends compressed digital video signal information to the video remote control 170 by RF communication. The docking station and the video remote control 170 are provided with an RF antenna and receivers 112 and 152. Digital commands and information signals are exchanged between the docking station and the video remote control 170 and the functions of the TV and the other video device are controlled from the remote control. COPYRIGHT: (C)2000,JPO

Luminance channel modulated watermarking of digital images

Abstract: Digital watermarking of digital images allow authentication of ownership and protection of intellectual property. We consider an algorithm wherein a luminance channel modulated watermark is embedded in the blue channel of a color image. The blue channel image is decomposed via a wavelet transform, and the embedding strength is varied depending on the resolution band. The resolution band weighting improves the algorithms' watermark recovery performance when distortion is introduced due to lossy compression.

Mobile communication terminal equipment

Abstract: PROBLEM TO BE SOLVED: To improve quality in an image pickup signal by preventing the adverse effect of the electromagnetic noise of a radio exchange signal on the image pickup signal which is outputted from a camera. SOLUTION: An exchange period deciding means 21a respectively detects a transmission channel CH2 period and a reception channel CH3 period in a main control part 21 during TV telephone communication and a camera output stop control means 21b gives a control signal SC for stopping the output of the image pickup signal in the camera 33 to the camera 33 in the respective detection periods. Then the output of the image pickup signal from the camera 33 is stopped.