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Showing papers on "Channel (digital image) published in 2005"


Journal ArticleDOI
TL;DR: This work quantifies the specific correlations introduced by CFA interpolation, and describes how these correlations can be automatically detected in any portion of an image and shows the efficacy of this approach in revealing traces of digital tampering in lossless and lossy compressed color images interpolated with several different CFA algorithms.
Abstract: With the advent of low-cost and high-resolution digital cameras, and sophisticated photo editing software, digital images can be easily manipulated and altered. Although good forgeries may leave no visual clues of having been tampered with, they may, nevertheless, alter the underlying statistics of an image. Most digital cameras, for example, employ a single sensor in conjunction with a color filter array (CFA), and then interpolate the missing color samples to obtain a three channel color image. This interpolation introduces specific correlations which are likely to be destroyed when tampering with an image. We quantify the specific correlations introduced by CFA interpolation, and describe how these correlations, or lack thereof, can be automatically detected in any portion of an image. We show the efficacy of this approach in revealing traces of digital tampering in lossless and lossy compressed color images interpolated with several different CFA algorithms.

614 citations


Journal ArticleDOI
TL;DR: The experimental results show that the presented color demosaicking technique outperforms the existing methods both in PSNR measure and visual perception.
Abstract: Digital cameras sample scenes using a color filter array of mosaic pattern (e.g., the Bayer pattern). The demosaicking of the color samples is critical to the image quality. This paper presents a new color demosaicking technique of optimal directional filtering of the green-red and green-blue difference signals. Under the assumption that the primary difference signals (PDS) between the green and red/blue channels are low pass, the missing green samples are adaptively estimated in both horizontal and vertical directions by the linear minimum mean square-error estimation (LMMSE) technique. These directional estimates are then optimally fused to further improve the green estimates. Finally, guided by the demosaicked full-resolution green channel, the other two color channels are reconstructed from the LMMSE filtered and fused PDS. The experimental results show that the presented color demosaicking technique outperforms the existing methods both in PSNR measure and visual perception.

379 citations


Journal ArticleDOI
01 Jul 2005
TL;DR: The Color2Gray results offer viewers salient information missing from previous grayscale image creation methods.
Abstract: Visually important image features often disappear when color images are converted to grayscale. The algorithm introduced here reduces such losses by attempting to preserve the salient features of the color image. The Color2Gray algorithm is a 3-step process: 1) convert RGB inputs to a perceptually uniform CIE L*a*b* color space, 2) use chrominance and luminance differences to create grayscale target differences between nearby image pixels, and 3) solve an optimization problem designed to selectively modulate the grayscale representation as a function of the chroma variation of the source image. The Color2Gray results offer viewers salient information missing from previous grayscale image creation methods.

311 citations


Book ChapterDOI
09 May 2005
TL;DR: The experiment performed by program based on aforementioned algorithms indicates that the LPR system based on color image processing is quite quick and accurate.
Abstract: A License plate recognition (LPR) system can be divided into the following steps: preprocessing, plate region extraction, plate region thresholding, character segmentation, character recognition and post-processing. For step 2, a combination of color and shape information of plate is used and a satisfactory extraction result is achieved. For step 3, first channel is selected, then threshold is computed and finally the region is thresholded. For step 4, the character is segmented along vertical, horizontal direction and some tentative optimizations are applied. For step 5, minimum Euclidean distance based template matching is used. And for those confusing characters such as '8' & 'B' and '0' & 'D', a special processing is necessary. And for the final step, validity is checked by machine and manual. The experiment performed by program based on aforementioned algorithms indicates that our LPR system based on color image processing is quite quick and accurate.

209 citations


Patent
26 Apr 2005
TL;DR: In this article, a method for correcting a channel dependent color aberration in a digital image, where the digital image is composed of a plurality of color channels, is described, and a digital capture apparatus is described for use therewith.
Abstract: A method, and digital capture apparatus for use therewith, is described for correcting a channel dependent color aberration in a digital image, where the digital image is composed of a plurality of color channels. The method includes capturing an image comprising the color channels, where one of the color channels is a blurred color channel due to a channel dependent color aberration affecting that channel. Then, one of the other color channels, other than the blurred color channel, is used as an indication of an aim sharpness, and the sharpness of the blurred color channel is adjusted, at least partially, toward the aim sharpness.

144 citations


Journal ArticleDOI
TL;DR: In order to fuse two registered high spatial resolution panchromatic image and low spatial resolution multispectral image of the same scene, a new color transfer based fusion algorithm by using the non-separable wavelet frame transform (NWFT) is proposed.

106 citations


Patent
01 Jul 2005
TL;DR: In this article, an edge detection filter circuit was used to aid in acquiring and identifying targets in a fusion night vision system with image intensification and thermal imaging capabilities. But, it was not shown how to combine the thermal image with the image intensifying image without obscuration of the intensification image.
Abstract: A fusion night vision system having image intensification and thermal imaging capabilities includes an edge detection filter circuit to aid in acquiring and identifying targets. An outline of the thermal image is generated and combined with the image intensification image without obscuration of the image intensification image. The fusion night vision system may also include a parallax compensation circuit to overcome parallax problems as a result of the image intensification channel being spaced from the thermal channel. The fusion night vision system may also include a control circuit configured to maintain a perceived brightness through an eyepiece over a mix of image intensification information and thermal information. The fusion night vision system may incorporate a targeting mode that allows an operator to acquire a target without having the scene saturated by a laser pointer. The night vision system may also include a detector, an image combiner for forming a fused image from the detector and a display, and a camera aligned with image combiner for recording scene information processed by the first detector.

99 citations


Journal ArticleDOI
TL;DR: Simulation results show that the proposed concealment technique using data hiding outperforms existing approaches in improving the perceptual quality, especially in the case of higher loss probabilities.
Abstract: A robust error concealment scheme using data hiding which aims at achieving high perceptual quality of images and video at the end-user despite channel losses is proposed. The scheme involves embedding a low-resolution version of each image or video frame into itself using spread-spectrum watermarking, extracting the embedded watermark from the received video frame, and using it as a reference for reconstruction of the parent image or frame, thus detecting and concealing the transmission errors. Dithering techniques have been used to obtain a binary watermark from the low-resolution version of the image/video frame. Multiple copies of the dithered watermark are embedded in frequencies in a specific range to make it more robust to channel errors. It is shown experimentally that, based on the frequency selection and scaling factor variation, a high-quality watermark can be extracted from a low-quality lossy received image/video frame. Furthermore, the proposed technique is compared to its two-part variant where the low-resolution version is encoded and transmitted as side information instead of embedding it. Simulation results show that the proposed concealment technique using data hiding outperforms existing approaches in improving the perceptual quality, especially in the case of higher loss probabilities.

98 citations


Patent
28 Jul 2005
TL;DR: In this paper, strategies for processing image information in a linear form to reduce the amount of artifacts (compared to processing the data in non-linear form) are described for scaling, compositing, alpha-blending, edge detection, and so forth.
Abstract: Strategies are described for processing image information in a linear form to reduce the amount of artifacts (compared to processing the data in nonlinear form). Exemplary types of processing operations can include, scaling, compositing, alpha-blending, edge detection, and so forth. In a more specific implementation, strategies are described for processing image information that is: a) linear; b) in the RGB color space; c) high precision (e.g., provided by floating point representation); d) progressive; and e) full channel. Other improvements provide strategies for: a) processing image information in a pseudo-linear space to improve processing speed; b) implementing an improved error dispersion technique; c) dynamically calculating and applying filter kernels; d) producing pipeline code in an optimal manner; and e) implementing various processing tasks using novel pixel shader techniques.

92 citations


Patent
08 Mar 2005
TL;DR: In this article, a method for registration of a sequence of 2D image data (5) of a vessel, recorded with an imaging endoluminal instrument (1) in the hollow channel (2) is presented.
Abstract: The present invention relates to a method for registration of a sequence of 2D image data (5) of a hollow channel (2), in particular of a vessel, recorded with an imaging endoluminal instrument (1) when the relative displacement positions of the instrument (1) in the hollow channel (2) are known, with 3D image data (8) of the hollow channel (2). In the method a three-dimensional path of a central axis (10) of a definable section of the hollow channel (2) is determined from the 3D image data (8), the three-dimensional path of the central axis (10) is converted into a rectilinear path by a first transformation of the 3D image data (8) of the definable section of the hollow channel (2) and transformation parameters required for the first transformation are stored. A combined 3D image data record (11) is generated from the sequence of 2D image data (5) by a parallel side-by-side arrangement on a central straight line in accordance with the known relative displacement positions, and is first registered with the transformed 3D image data (9) by equating the central straight line with the rectilinear path of the central axis (10) and suitable translation for superposition of a shared reference point. The combined 3D image data record (11) or 2D image data (5) contained therein is then registered with the 3D image data (3), taking into account the stored transformation parameters.

69 citations


Journal ArticleDOI
TL;DR: A novel support vector regression based color image watermarking scheme is proposed that outperform the Kutter's method and Yu's method against different attacks including noise addition, shearing, luminance and contrast enhancement, distortion, etc.

Journal ArticleDOI
TL;DR: In this article, a non-intrusive method of two-phase flow identification is investigated based on image processing of data obtained partly from dynamic neutron radiography recordings of real twophase flow in a heated metal channel, and partly by visible light from a two-component mixture of water and air.

Journal ArticleDOI
TL;DR: Kim et al. as mentioned in this paper compared the performance of feature tracking, particle image velocimetry and particle tracking velocicometrics in a turbulent channel flow and found that feature tracking performances were rather good, even in its purely translational motion model implementation No constraints on tracer density have to be introduced No restriction on tracers density have been introduced, and the accuracy and resolution are always comparable to those achieved by the other techniques.
Abstract: The presence of a large number of software codes for image analysis suggests the need for testing the suitability and accuracy of the algorithms developed One of the possible approaches is testing these systems with experiments of well-known flow properties Alternatively, tests can be performed by analysing synthetically generated images The advantage of the latter approach is that there is no need to set up an experiment and the flow field is known in detail This paper provides some insights into the relationship between results on both real and synthetic images in a turbulent channel flow We focus on comparing performances of feature tracking, a novel image analysis technique, particle image velocimetry and particle tracking velocimetry The three techniques have been used to explore first- and second-order statistics The results are compared to direct numerical simulations of turbulent flow in a channel (Kim J, Moin P and Moser R 1987 Turbulence in channel flow at low Reynolds number J Fluid Mech 177 133–66) Feature tracking performances are rather good, even in its purely translational motion model implementation No constraints on tracer density have to be introduced More than 3000 velocity vectors per frame were reconstructed Resulting accuracy and resolution are always comparable to those achieved by the other techniques

Patent
Eunice Poon1, Megumi Kanda1, Ian Clarke1
10 May 2005
TL;DR: In this article, the authors converted an object RGB image into an image in a YIQ color space, and computed a smoothness degree of luminance variation at the target pixel as summation of absolute values of differences between luminance variations at each target pixel and adjacent pixels.
Abstract: The technique of the invention converts an object RGB image into an image in a YIQ color space, calculates a luminance variation at each target pixel from Y channel values of the target pixel and an adjacent pixel adjoining to the target pixel, and computes a smoothness degree of luminance variation at the target pixel as summation of absolute values of differences between luminance variations at the target pixel and adjacent pixels. A block noise evaluation value B is obtained as a ratio of an average smoothness degree ave(psx), ave(psy) of luminance variation for boundary pixels located on each block boundary to an average smoothness degree ave(nsx), ave(nsy) of luminance variation for inner pixels not located on the block boundary. The block noise evaluation value B closer to 1 gives an evaluation result of a lower level of block noise, whereas the block noise evaluation value B closer to 10 gives an evaluation result of a higher level of block noise.

Patent
08 Mar 2005
TL;DR: In this article, a method for imaging using an image-generating, endoluminal instrument by means of which a sequence of 2D image data of a vessel, of an object under investigation, is recorded, wherein the images are recorded in a known temporal relation to a periodic movement of the object under investigations and spatial coordinates of the image are captured by a position sensor during each recording of an image.
Abstract: The present invention relates to a method for imaging using an image-generating, endoluminal instrument (1) by means of which a sequence of 2D image data of a hollow channel (2), in particular a vessel, of an object under investigation is recorded, wherein the images are recorded in a known temporal relation to a periodic movement of the object under investigation and spatial coordinates of the image are captured by means of a position sensor during each recording of an image (5) and stored as position data (9, 10) together with the 2D image data of the image (5). The method is characterized in that first position data (10) which does not lie in a predefinable movement phase of the object under investigation is corrected, before or after being stored, by interpolation between second position data (9) which does lie in the specified movement phase and/or by subtraction or addition of predetermined values. By means of the method a movement correction of the data can be performed without the need to reduce the volume of recorded image material.

01 Jan 2005
TL;DR: In this paper, a computer-based procedure was developed to precisely determine the geometric distortions of the red and blue image channel (plane) in comparison to the green reference channel, and the results obtained are presented numerically and graphically.
Abstract: The effects of (monochromatic and chromatic) lens aberrations in optical imaging are well documented in the literature. These geometrical imperfections are caused by the physical parameters of the optical system (lens) of the photographic camera and apply to both analog and digital cameras. All these aberrations produce lateral distortions (geometric errors) and/or longitudinal distortions (image blur) in one way or another. In this paper we focus on the elimination of the effect of lateral chromatic aberration within a post-processing step after image acquisition. This task has already become a vital topic with the advent of digital (consumer) cameras. Many references can be found in the World Wide Web. Several methods, from simple heuristic to more stringent ones, are proposed by the user community. Since the usage of digital consumer cameras (SLR or compact cameras) in documentation and mapping of cultural heritage is becoming more and more wide-spread, the present topic should be discussed in more detail. Color fringes are inherent to all analog and digital (color) photographs taken by cameras for which chromatic aberration is not sufficiently corrected for. The width of color fringes, mainly introduced by lateral chromatic aberration, is smallest around the image center and greatest in the corners of the photographs. The authors have developed a computer-based procedure to precisely determine the geometric distortions of the red and blue image channel (plane) in comparison to the green reference channel. Least-squares matching is employed at distinct corner points found by an interest operator in order to measure point displacements. The paper also describes how these measurements can be carried out using a commercial software, i.e. PhotoModeler 5.0. In a first approximation the three RGB color channels differ in scale, i.e. they are radially displaced. Originally, the DistCorr software has been developed in order to compensate for lens distortion to obtain perfect central-perspective images. The software mentioned was readily modified for correction of lateral chromatic aberration. As a result, the geometrically re-scaled red and blue image planes are registered to the green one. The amount of image displacement of the two color channels can be specified as an additive correction to the linear parameter of the radial-symmetric lens distortion formula. Lateral color fringes can thus be eliminated to a great extent with this simple method. This paper also presents examples of practical investigations. Three lenses (17 mm, 20 mm, 50 mm) of a digital consumer camera, i.e. a Nikon D100 SLR with 6 Megapixels, were analyzed. The results obtained are presented numerically and graphically. An outlook on further improvements in the elimination of color fringes is given at the end of the paper.

Journal ArticleDOI
TL;DR: Feature selection for the development of automated skin lesion discrimination systems is an important consideration and asymmetry, border irregularity, color variegation, and diameter of the skin lesions in dermatology for diagnosing malignant melanoma are considered.
Abstract: Physicians’ low accuracy in diagnosing pigmented lesions has been well documented (1–4). In three previous studies of diagnostic accuracy, sensitivity for malignant melanoma detection by dermatologists without aids such as dermoscopy was 89%, 77%, and 81% (2–4). Many physicians rely on guidelines such as asymmetry, border irregularity, color variegation, and diameter of the skin lesion, called the ABCD criteria (5). Conventional educational programs can improve diagnostic accuracy, but some discriminations such as melanoma vs. dysplastic nevi remain difficult (6). Many factors affect the success of automated melanoma recognition systems. The quality of the data is one such factor. If information is irrelevant or redundant, or the data are noisy and unreliable, then knowledge discovery during training is more difficult. The performance of the classification process depends on the quality of the features used in the process. So feature selection is often an essential data-processing step prior to applying a classification algorithm. Feature subset selection (feature reduction) is the process of identifying and removing as much of the irrelevant and redundant information as possible. The purpose of this feature subset selection is to select the smallest subset of features without degrading lesion classification performance. By carrying out feature selection before feeding the whole feature set into a classification system, the performance of the classification system can often be improved. In this research, shape and color descriptors for clinical skin lesion images are evaluated to determine which features contribute most successfully to discriminating melanoma from benign lesions. Statistical-, histogram-, and rule-based approaches are utilized for feature evaluation and feature set reduction to improve lesion discrimination. Numerous computer-based techniques have been applied to pigmented lesion images, both clinical and dermoscopy, for investigating features to detect malignant melanoma (7–25). In the research presented here, skin lesion shape and color feature analysis is examined for clinical images. Skin lesion border irregularity has been analyzed by Golston et al. (13) using circular indices. Skin lesion asymmetry has been analyzed by Stoecker et al. (12). Irregularity and asymmetry measures have been reported to correlate with dermatologists’ measures of these features in 92% and 93% of instances, respectively (12, 13). Clinical examination of color provides discriminating information in the diagnosis of malignant melanoma (5). There are colors generally associated with melanocytic lesions, including shades of tan, brown, or black and occasional patches of red, white, or blue. Colors characteristic of melanoma can be represented using various color spaces (11, 17). Several color descriptors have been applied to melanoma detection or discrimination, including variation of hues (8), analytical color techniques for detecting color variegation (17), and RGB color channel statistical parameters (23–25). Ercal et al. (11) utilized relative chromaticity, spherical color coordinates, and (L, a*, b*) color coordinate features as part of an overall neural network approach for melanoma detection. Ganster et al. (14) also used a neural network-based melanoma detection scheme that utilized absolute, unnormalized color-based percent melanoma color features for melanoma color discrimination in dermoscopy images. The color features included the percentages of absolute color shades of reddish, bluish, grayish, and blackish areas found within the skin lesion as well as the number of these colors present within the skin lesion. Color quantization was performed using the median-cut color quantization algorithm (26). The remainder of the paper is organized as follows: (1) description of skin lesion features, (2) feature evaluation experiments performed, (3) experimental results, (4) discussion, and (5) conclusions.

Journal ArticleDOI
TL;DR: The INeN is proposed to determine the number of classes automatically and the Kohonen network is employed for the segmentation of the remote-sensing images.

Journal ArticleDOI
TL;DR: This paper proposes a scheme to meet the need of authenticating degraded images despite lossy compression and packet loss by incorporating a watermarking solution into a traditional crypto signature scheme to make the digital signatures robust to image degradations.
Abstract: With the ambient use of digital images and the increasing concern on their integrity and originality, consumers are facing an emergent need of authenticating degraded images despite lossy compression and packet loss. In this paper, we propose a scheme to meet this need by incorporating watermarking solution into traditional cryptographic signature scheme to make the digital signatures robust to these image degradations. Due to the unpredictable degradations, the pre-processing and block shuffling techniques are applied onto the image at the signing end to stabilize the feature extracted at the verification end. The proposed approach is compatible with traditional cryptographic signature scheme except that the original image needs to be watermarked in order to guarantee the robustness of its derived digital signature. We demonstrate the effectiveness of this proposed scheme through practical experimental results.

Patent
Choi Jong In1
15 Sep 2005
TL;DR: In this article, an apparatus and method for switching a channel of a digital television is described, which allows a window on a screen to be slid and results in minimization or a user eyestrain caused by a channel switching operation.
Abstract: An apparatus and method for switching a channel of a digital television is disclosed. The apparatus for switching a channel of the digital TV comprises a image processor for performing scaling of image data input to match an output image size; a frame storage unit for storing the image frames scaled by the image processor; and a controller for allowing a image frame of a first channel and a image frame of a second channel scaled by the image processor to be displayed as a single image. Therefore, the apparatus allows a window on a screen to be slid and results in minimization or a user eyestrain caused by a channel switching operation.

Proceedings ArticleDOI
23 May 2005
TL;DR: Experimental results show that the new edge adaptive color demosaicing method for Bayer pattern images of single-sensor digital cameras achieves both higher signal fidelity and higher visual image quality as compared with some existing schemes.
Abstract: A new edge adaptive color demosaicing method for Bayer pattern images of single-sensor digital cameras is presented in this paper. An edge direction detector for narrow edges is proposed by making full use of inter-channel correlation to determine edge directions within the smallest detection radius. A combinative criterion is then formulated to cater for the diversity of edge occurrence in real-world scenes. The improvement of the proposed demosaicing scheme is achieved by an effective detection on edge directions, emphasizing on green channel restoration and the overall refinement. Experimental results show that the new scheme preserves better edge details, reduces color aliasing artifacts, and achieves both higher signal fidelity and higher visual image quality as compared with some existing schemes.

Proceedings ArticleDOI
17 Jan 2005
TL;DR: In this paper, the mean, standard deviation and histogram distribution of a set of natural scene images are used as the target color properties for each color scheme, and the final grayscale image segments are obtained by using clustering and merging techniques.
Abstract: A natural color mapping method has been previously proposed that matches the statistical properties (mean and standard deviation) of night-vision (NV) imagery to those of a daylight color image (manually selected as the "target" color distribution). Thus the rendered NV image appears to resemble the target image in terms of colors. However, in this prior method the colored NV image may appear unnatural if the target image's "global" color statistics are too different from that of the night vision scene (e.g., it would appear to have too much green if much more foliage was contained in the target image). Consequently, a new "local coloring" method is presented in the current paper, and functions to render the NV image segment-by-segment by using a histogram matching technique. Specifically, a false-color image (source image) is formed by assigning multi-band NV images to three RGB (red, green and blue) channels. A nonlinear diffusion filter is then applied to the false-colored image to reduce the number of colors. The final grayscale image segments are obtained by using clustering and merging techniques. The statistical matching procedure is merged with the histogram matching procedure to assure that the source image more closely resembles the target image with respect to color. Instead of using a single target color image, the mean, standard deviation and histogram distribution of a set of natural scene images are used as the target color properties for each color scheme. Corresponding to the source region segments, the target color schemes are grouped by their scene contents (or colors) such as green plants, roads, ground/earth. In our experiments, five pairs of night-vision images were initially analyzed, and the images that were colored (segment-by-segment) by the proposed "local coloring" method are shown to be much more natural, realistic, and colorful when compared with those produced by the "global-coloring" method.

Journal ArticleDOI
TL;DR: A technique to provide interferometry by combining multiple images of the same area via the cross-relations (CR) technique, which provides significant improvements with respect to conventional approaches based either on independent analysis of single interferograms or multi-baselines phase analysis of current literature.
Abstract: We propose a technique to provide interferometry by combining multiple images of the same area. This technique differs from the multi-baseline approach in literature as (a) it exploits all the images simultaneously, (b) it performs a spectral shift preprocessing to remove most of the decorrelation, and (c) it exploits distributed targets. The technique is mainly intended for DEM generation at centimetric accuracy, as well as for differential interferometry. The problem is framed in the contest of single-input multiple-output (SIMO) channel estimation via the cross-relations (CR) technique and the resulting algorithm provides significant improvements with respect to conventional approaches based either on independent analysis of single interferograms or multi-baselines phase analysis of single pixels of current literature, for those targets that are correlated in all the images, like for long-term coherent areas, or for acquisitions taken with a short revisit time (as those gathered with future satellite constellations).

Patent
08 Jun 2005
TL;DR: In this article, a method of transferring images captured by a digital capture device to a remote memory location over a channel includes capturing a plurality of digital images using the digital capture devices and storing the plurality of images in a local memory.
Abstract: A method of transferring images captured by a digital capture device to a remote memory location over a channel includes capturing a plurality of digital images using the digital capture device and storing the plurality of images in a local memory. The method also includes providing a plurality of user selectable times for the transfer of images over the channel from the local memory to the remote memory location and a user selecting one of the user selectable times, and transferring the plurality of images over the channel to the remote memory location at the user selected time.

Patent
24 Aug 2005
TL;DR: In this paper, a compressing encoding and decoding method which includes the following: encoding the video compressed signals with the programs, discrete cosine transform DCT; transform and quantitate; set the channel buffer storage before the encoding bit flow gets into the channel; the buffer storage must have a control mechanism; movement estimate; the position excursion is described by the movement vector, and a movement vector represents the displacement in the two actinic and vertical directions.
Abstract: A compressing encoding and decoding method which includes the following: encode the video compressed signals with the programs, discrete cosine transform DCT; transform and quantitate; set the channel buffer storage before the encoding bit flow gets into the channel; the buffer storage must have a control mechanism; movement estimate; the position excursion is described by the movement vector, and a movement vector represents the displacement in the two actinic and vertical directions; as movement estimating, the P frame image uses the former most recent decoded I frame or P frame as the referenced image called the forward forecast; the movement compensation; the movement vector calculated by the movement estimate moves the macro piece in the referenced image to the corresponding position in the actinic and vertical direction, then namely produce the forecast to the compressed image; and search and calculate the subpels; the quantitation, storage and movement search after the sampling signals are made the discrete cosine transform DCT transform are all completed in the frequency field. The video encoder finishes all the calculation in the frequency field. The compressed rate is high, and the calculating quantity is small.

Patent
05 May 2005
TL;DR: In this article, a method and apparatus for combining statistical eye channel compliance methods with linear continuous-time equalization is presented, which allows for the addition of linear continuous time equalization with or without modification of the existing statistical eye algorithm.
Abstract: A method and apparatus for combining statistical eye channel compliance methods with linear continuous-time equalization. A set of equalizer parameters is processed with measured channel parameters to create a set of modified parameters that are then used with a statistical eye algorithm. This technique allows for the addition of linear continuous-time equalization with or without modification of the existing statistical eye algorithm.

Patent
30 Sep 2005
TL;DR: In this article, an image-rejecting channel estimator for OFDM receivers employing scattered pilot channel estimates is presented, which includes an estimation interpolator configured to provide channel estimates through time interpolation and frequency interpolation.
Abstract: The present invention provides an image-rejecting channel estimator for use with an orthogonal frequency division multiplex (OFDM) receiver employing scattered pilot channel estimates. In one embodiment, the image-rejecting channel estimator includes an estimation interpolator configured to provide channel estimates through time interpolation and frequency interpolation employing the scattered pilot channel estimates. The image-rejecting channel estimator also includes an image-rejection formatter coupled to the estimation interpolator and configured to provide image-rejection filtering to suppress an image in an output spectrum of the channel estimates from at least one of the time interpolation and frequency interpolation.

Patent
Xing Li1
20 Jul 2005
TL;DR: In this article, an original image is received in a red-green-blue color space and pixels in the original image are converted to a luminance-chrominance color space.
Abstract: An original image is received in a red-green-blue color space. Pixels in the original image are converted to a luminance-chrominance color space. Background pixels in the original image are determined by comparing a luminance value of each pixel to a selectable luminance threshold, and comparing chrominance value of each pixel to a predetermined chrominance threshold. Chrominance values of the background pixels in each chrominance channel are adjusted.

01 Jan 2005
TL;DR: This image represents the fitted image of the channel kCh, ppa iCh image image data of undersampled raw data of theChannel iCh and kCh iCh f, the fitting coefficient, which is obtained by the Fourier transform of the convolution.
Abstract: full kCh image represent the fitted image of the channel kCh , ppa iCh image image data of undersampled raw data of the channel iCh and kCh iCh f , the fitting coefficient, which is obtained by the Fourier transform of the convolution

Patent
07 Dec 2005
TL;DR: In this article, a method for producing an enhanced color image of a scene of interest using a flash of infrared light and a color image without using any flash of IR light is presented.
Abstract: A device and method for producing an enhanced color image of a scene of interest captures a grayscale image of the scene of interest using a flash of infrared light and a color image of the scene of interest without using any flash of infrared light. The grayscale information from the grayscale image and the visible color information from the color image are combined to produce the enhanced color image.