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Joan Llach, Princeton US

Joan Llach, Princeton, NJ US

Patent application numberDescriptionPublished
20090238406Dynamic state estimation - According to an implementation, a set of particles is provided for use in estimating a location of a state of a dynamic system. A local-mode seeking mechanism is applied to move one or more particles in the set of particles, and the number of particles in the set of particles is modified. The location of the state of the dynamic system is estimated using particles in the set of particles. Another implementation provides dynamic state estimation using a particle filter for which the particle locations are modified using a local-mode seeking algorithm based on a mean-shift analysis and for which the number of particles is adjusted using a Kullback-Leibler-distance sampling process. The mean-shift analysis may reduce degeneracy in the particles, and the sampling process may reduce the computational complexity of the particle filter. The implementation may be useful with non-linear and non-Gaussian systems.09-24-2009
20090251490Data Hiding Technique - Information available at a decoder is embedded into image content after decoding by first representing that information by at least one film grain pattern and then blending that at least one film grain pattern with the decoded image content. Such image content is typically in the form of a movie and examples of the information to be embedded include identification of the specific decoding device, the user of the decoding device, the time and date of decoding, the model number of the device, the versions of software running on the device, the status of the device or connections to the device, the contents of device registers or memory locations within the device, among many other possible data. When an unauthorized copy of image content is discovered, the copied image content undergoes a comparison to the decoded image content to generate difference data. Thereafter, the difference data undergoes comparison with a database of film grain patterns to recover the embedded data.10-08-2009
20090278988Adaptive pixel-based filtering - In an implementation, a pixel is selected from a target digital image. Multiple candidate pixels, from one or more digital images, are evaluated based on values of the multiple candidate pixels. For the selected pixel, a corresponding set of pixels is determined from the multiple candidate pixels based on the evaluations of the multiple candidate pixels and on whether a predetermined threshold number of pixels have been included in the corresponding set. Further for the selected pixel, a substitute value is determined based on the values of the pixels in the corresponding set of pixels. Various implementations described provide adaptive pixel-based spatio-temporal filtering of images or video to reduce film grain or noise. Implementations may achieve an “even” amount of noise reduction at each pixel while preserving as much picture detail as possible by, for example, averaging each pixel with a constant number, N, of temporally and/or spatially correlated pixels.11-12-2009
20090304270REDUCING CONTOURS IN DIGITAL IMAGES - One or more implementations access a digital image containing one or more bands. Adjacent bands of the one or more bands have a difference in color resulting in a contour between the adjacent bands. The one or more implementations apply an algorithm to at least a portion of the digital image for reducing visibility of a contour. The algorithm is based on a value representing the fraction of pixels in a region of the digital image having a particular color value.12-10-2009
20090324121Automatic parameter estimation for adaptive pixel-based filtering - One particular automatic parameter estimation method and apparatus estimates low level filtering parameters from one or more user controlled high-level filtering parameters. The high level filtering parameters are strength and quality, where strength indicates how much noise reduction will be performed, and quality indicates a tolerance which controls the balance between filtering uniformity and loss of detail. The low level filtering parameters that can be estimated include the spatial neighborhood and/or temporal neighborhood size from which pixel candidates are selected, and thresholds used to verify the “goodness” of the spatially or temporally predicted candidate pixels. More generally, a criterion for filtering digital image data is accessed, and a value is determined for a parameter for use in filtering digital image data, the value being determined based on whether the value results in the criterion being satisfied for at least a portion of a digital image.12-31-2009
20100026887Method and apparatus for reversible, polynomial based image scaling - A method and apparatus are provided for reversible, polynomial based image scaling. The apparatus includes a video scaler for performing image scaling from a first base resolution image to a higher resolution image, and from the higher resolution image to a second base resolution image. The first and the second base resolution images are equal on a pixel-by-pixel basis for an entirety of the first and the second base resolution images. A scaling function used for the image scaling is based on a polynomial function having two or more degrees.02-04-2010
20100054536ESTIMATING A LOCATION OF AN OBJECT IN AN IMAGE - An implementation provides a method including forming a metric surface in a particle-based framework for tracking an object, the metric surface relating to a particular image in a sequence of digital images. Multiple hypotheses are formed of a location of the object in the particular image, based on the metric surface. The location of the object is estimated based on probabilities of the multiple hypotheses.03-04-2010
20100067802ESTIMATING A LOCATION OF AN OBJECT IN AN IMAGE - An implementation provides a method for estimating a location for an object in a particular image of a sequence of images. The location is estimated using a particle-based framework, such as a particle filter. It is determined that the estimated location for the object in the particular image is occluded. A trajectory is estimated for the object based on one or more previous locations of the object in one or more previous images in the sequence of images. The estimated location of the object is changed based on the estimated trajectory.03-18-2010
20100067803ESTIMATING A LOCATION OF AN OBJECT IN AN IMAGE - An implementation provides a method for determining a trajectory of an object in a particular image in a sequence of digital images, the trajectory being based on one or more previous locations of the object in one or more previous images in the sequence. A weight is determined, for a particle in a particle-based framework for tracking the object, based on distance from the trajectory to the particle. A location estimate is determined for the object using the particle-based framework, the location estimate being based on the determined particle weight.03-18-2010
20100080455Film grain simulation method - Briefly, in accordance with a preferred embodiment of the present principles, simulation of a block of film grain for addition to a block of an image occurs by first establishing at least one image parameter in accordance with at least one attribute of the block. Thereafter, a block of film grain is established in accordance with the image parameter. Deblocking filtering can be applied to the film grain block.04-01-2010
20100098307METHOD AND APPARATUS FOR DETECTING OBJECTS OF INTEREST IN SOCCER VIDEO BY COLOR - A method is disclosed for detecting and locating players in soccer video frames without errors caused by artifacts by a shape analysis-based approach to identify the players and the ball from roughly extracted foregrounds obtained by color segmentation and connected component analysis, by performing a Euclidean distance transform to extract skeletons for every foreground blob, by performing a shape analysis to remove false alarms (non-players and non-ball), and then by performing skeleton pruning and a reverse Euclidean distance transform to cut-off the artifacts primarily caused by playing field lines.04-22-2010
20100128789METHOD AND APPARATUS FOR PROCESSING VIDEO SEQUENCES - A method for processing a video sequence having a plurality of frames includes the steps of: extracting features from each of the frames, determining correspondences between the extracted features from two of the frames, estimating motion in the video sequence based on the determined correspondences, generating a background mosaic for the video sequence based on the estimated motion, and performing foreground-background segmentation on each of the frames based on the background mosaic.05-27-2010
20100142808IDENTIFYING BANDING IN DIGITAL IMAGES - One or more implementations access a digital image and determine whether at least one portion of the digital image includes one or more bands having a difference in color. The determination is based on at least two candidate scales. One or more implementations access a digital image and assess at least a portion of the digital image for the existence of one or more bands having a difference in color. The assessing includes determining a fraction of pixels in the portion having a color value offset by an offset value from a color value of a particular pixel in the portion.06-10-2010
20100329554Automatic exposure estimation for HDR images based on image statistics - A method for tone mapping high dynamic range images for display on low dynamic range displays wherein high dynamic range images are first accessed. The high dynamic range images are divided the into different regions such that each region is represented by a matrix, where each element of the matrix is a weight or probability of a pixel value. An exposure of each region is determined or calculated by estimating an anchor point in each region such that most pixels in each region are mapped to mid grey and the anchor points are adjusted to a key of the images to preserve overall brightness. The regions are then placed or mapped to zones and exposure values are applied to the regions responsive to the weight or probability. The regions are fused together to obtain a final tone mapped image.12-30-2010
20100329557Automatic exposure estimation for HDR images based on image statistics - A method of segmenting regions of an image wherein a number of partitions are determined based on a range of an image histogram in a logarithmic luminance domain. Regions are defined by the partitions. A mean value of each region is calculated by K-means clustering wherein the clustering is initialized, data is assigned and centroids are updated. Anchor points are determined based on the centroids and a weight of each pixel is computed based on the anchor points.12-30-2010
20110026606SYSTEM AND METHOD FOR ENHANCING THE VISIBILITY OF AN OBJECT IN A DIGITAL PICTURE - The visibility of an object in a digital picture is enhanced by comparing an input video of the digital picture with stored information representative of the nature and characteristics of the object to develop object localization information that identifies and locates the object. The visibility of the object and the region in which the object is located is enhanced by image processing and the enhanced input video is encoded.02-03-2011
20110026607SYSTEM AND METHOD FOR ENHANCING THE VISIBILITY OF AN OBJECT IN A DIGITAL PICTURE - The visibility of an object in a digital picture is enhanced by comparing an input video of the digital picture with stored information representative of the nature and characteristics of the object to develop object localization information that identifies and locates the object. The input video and the object localization information are encoded and transmitted to a receiver where the input video and the object localization information are decoded and the decoded input video is enhanced by the decoded object localization information02-03-2011
20110148858VIEW SYNTHESIS WITH HEURISTIC VIEW MERGING - Several implementations relate to view synthesis with heuristic view merging for 3D Video (3DV) applications. According to one aspect, a first candidate pixel from a first warped reference view and a second candidate pixel from a second warped reference view are assessed based on at least one of a backward synthesis process to assess a quality of the first and second candidate pixels, a hole distribution around the first and second candidate pixels, or on an amount of energy around the first and second candidate pixels above a specified frequency. The assessing occurs as part of merging at least the first and second warped reference views into a signal synthesized view. Based on the assessing, a result is determined for a given target pixel in the single synthesized view. The result may be determining a value for the given target pixel, or marking the given target pixel as a hole.06-23-2011
20110157229VIEW SYNTHESIS WITH HEURISTIC VIEW BLENDING - Various implementations are described. Several implementations relate to view synthesis with heuristic view blending for 3D Video (3DV) applications. According to one aspect, at least one reference picture, or a portion thereof, is warped from at least one reference view location to a virtual view location to produce at least one warped reference. A first candidate pixel and a second candidate pixel are identified in the at least one warped reference. The first candidate pixel and the second candidate pixel are candidates for a target pixel location in a virtual picture from the virtual view location. A value for a pixel at the target pixel location is determined based on values of the first and second candidate pixels.06-30-2011

Patent applications by Joan Llach, Princeton, NJ US