Patent application number | Description | Published |
20080291282 | Camera Calibration - Online camera calibration methods have been proposed whereby calibration information is extracted from the images that the system captures during normal operation and is used to continually update system parameters. However, such existing methods do not cope well with structure-poor scenes having little texture and/or 3D structure such as in a home or office environment. By considering camera families (a set of cameras that are manufactured at least partially in a common manner) it is possible to provide calibration methods which are suitable for use with structure-poor scenes. A prior distribution of camera parameters for a family of cameras is estimated and used to obtain accurate calibration results for individual cameras of the camera family even where the calibration is carried out online, in an environment which is structure-poor. | 11-27-2008 |
20080317331 | Recognizing Hand Poses and/or Object Classes - There is a need to provide simple, accurate, fast and computationally inexpensive methods of object and hand pose recognition for many applications. For example, to enable a user to make use of his or her hands to drive an application either displayed on a tablet screen or projected onto a table top. There is also a need to be able to discriminate accurately between events when a user's hand or digit touches such a display from events when a user's hand or digit hovers just above that display. A random decision forest is trained to enable recognition of hand poses and objects and optionally also whether those hand poses are touching or not touching a display surface. The random decision forest uses image features such as appearance, shape and optionally stereo image features. In some cases, the training process is cost aware. The resulting recognition system is operable in real-time. | 12-25-2008 |
20080317386 | Playback of Digital Images - A method of displaying digital images is described in which a display length indicator is received and digital images are accessed. A set of digital images are selected from the accessed digital images in accordance with the display length indicator and displayed in a predetermined order. The method may be performed by a computer program, which may be embodied on a computer readable medium. | 12-25-2008 |
20090284611 | Transferring of Digital Images - A method of transferring images from a first device to a second device and computer program code for performing this method is described. A connection characteristic for a connection between the first & second devices is determined and at least one image is selected from a plurality of images on the first device for transfer dependent upon both the connection characteristic and image selection criteria. The selected image(s) are then transferred over the connection from the first device to the second device. | 11-19-2009 |
20090290795 | Geodesic Image and Video Processing - A method of geodesic image and video processing is proposed. In an embodiment, the method uses a geodesic distance transform to construct an image filter. The filter can be used in a variety of image editing operations such as segmentation, denoising, texture smoothing, image stitching and cartooning. In one embodiment, the method may be made efficient by utilizing parallelism of the algorithm to carry out processing steps on at least two processing cores concurrently. This efficiency may enable high-resolution images and video to be processed at ‘real time’ rates without the need for specialist hardware. | 11-26-2009 |
20100119147 | IMAGE SEGMENTATION - Segmentation of foreground from background layers in an image may be provided by a segmentation process which may be based on one or more factors including motion, color, contrast, and the like. Color, motion, and optionally contrast information may be probabilistically fused to infer foreground and/or background layers accurately and efficiently. A likelihood of motion vs. non-motion may be automatically learned from training data and then fused with a contrast-sensitive color model. Segmentation may then be solved efficiently by an optimization algorithm such as a graph cut. Motion events in image sequences may be detected without explicit velocity computation. | 05-13-2010 |
20100171846 | Automatic Capture Modes - An image capture device is described which is operable in any one of a number of capture modes. The device comprises a camera, a memory and a processor. The memory stores a plurality of sets of capture triggers, with each set of capture triggers being associated with one of the plurality of capture modes. The processor selects one of the plurality of capture modes, such that the device is operable in the selected capture mode. In the selected capture mode, an image is captured automatically when a capture trigger within the associated set of capture triggers is satisfied. | 07-08-2010 |
20100201681 | Image Editing Consistent with Scene Geometry - Image editing which is consistent with geometry of a scene depicted in the image is described. In an embodiment a graphical user interface (GUI) is provided to enable a user to simply and quickly specify four corners of a rectangular frame drawn onto a source image using the GUI. In embodiments, the four corners are used to compute parameters of a virtual camera assumed to capture the image of the drawn frame. Embodiments of an image processing system are described which use the virtual camera parameters to control editing of the source image in ways consistent with the 3D geometry of the scene depicted in that image. In some embodiments out of bounds images are formed and/or realistic-looking shadows are synthesized. In examples, users are able to edit images and the virtual camera parameters are dynamically recomputed and used to update the edited image. | 08-12-2010 |
20100226547 | Multi-Modal Tone-Mapping of Images - A system for multi-modal mapping of images is described. Embodiments are described where the image mapping system is used for visualizing high dynamic range images such as medical images, satellite images, high dynamic range photographs and the like and also for compressing such images. In examples, high bit-depth images are tone-mapped for display on equipment of lower bit-depth without loss of detail. In embodiments, the image mapping system computes statistics describing an input image and fits a multi-modal model to those statistics efficiently. In embodiments, the multi-modal model is a Gaussian mixture model and a plurality of sigmoid functions corresponding to the multi-modal model are obtained. In an embodiment the sigmoid functions are added to form a tone-mapping function which is used to transform a high bit-depth image such as 16 or 12 bits per pixel to a low bit-depth image such as 8 bits per pixel. | 09-09-2010 |
20100272367 | IMAGE PROCESSING USING GEODESIC FORESTS - Image processing using geodesic forests is described. In an example, a geodesic forest engine determines geodesic shortest-path distances between each image element and a seed region specified in the image in order to form a geodesic forest data structure. The geodesic distances take into account gradients in the image of a given image modality such as intensity, color, or other modality. In some embodiments, a 1D processing engine carries out 1D processing along the branches of trees in the geodesic forest data structure to form a processed image. For example, effects such as ink painting, edge-aware texture flattening, contrast-aware image editing, forming animations using geodesic forests and other effects are achieved using the geodesic forest data structure. In some embodiments the geodesic forest engine uses a four-part raster scan process to achieve real-time processing speeds and parallelization is possible in many of the embodiments. | 10-28-2010 |
20100303380 | Automatic Dust Removal In Digital Images - Methods and a processing device are provided for restoring pixels damaged by artifacts caused by dust, or other particles, entering a digital image capturing device. A user interface may be provided for a user to indicate an approximate location of an artifact appearing in a digital image. Dust attenuation may be estimated and an inverse transformation, based on the estimated dust attenuation, may be applied to damaged pixels in order to recover an estimate of the underlying digital image. One or many candidate source patch may be selected based on having smallest pixel distances, with respect to a target patch area. The damaged pixels included in the target patch area may be considered when calculating the pixel distance with respect to candidate source patches. RGB values of corresponding pixels of source patches may be used to restore the damaged pixels included in the target patch area. | 12-02-2010 |
20110064303 | Object Recognition Using Textons and Shape Filters - Given an image of structured and/or unstructured objects, semantically meaningful areas are automatically partitioned from the image, each area labeled with a specific object class. Shape filters are used to enable capturing of some or all of the shape, texture, and/or appearance context information. A shape filter comprises one or more regions of arbitrary shape, size, and/or position within a bounding area of an image, paired with a specified texton. A texton comprises information describing the texture of a patch of surface of an object. In a training process a sub-set of possible shape filters is selected and incorporated into a conditional random field model of object classes. The conditional random field model is then used for object detection and recognition. | 03-17-2011 |
20110141121 | Parallel Processing for Distance Transforms - Parallel processing for distance transforms is described. In an embodiment a raster scan algorithm is used to compute a distance transform such that each image element of a distance image is assigned a distance value. This distance value is a shortest distance from the image element to the seed region. In an embodiment two threads execute in parallel with a first thread carrying out a forward raster scan over the distance image and a second thread carrying out a backward raster scan over the image. In an example, a thread pauses when a cross-over condition is met until the other thread meets the condition after which both threads continue. In embodiments distances may be computed in Euclidean space or along geodesics defined on a surface. In an example, four threads execute two passes in parallel with each thread carrying out a raster scan over a different quarter of the image. | 06-16-2011 |
20110188715 | Automatic Identification of Image Features - Automatic identification of image features is described. In an embodiment, a device automatically identifies organs in a medical image using a decision forest formed of a plurality of distinct, trained decision trees. An image element from the image is applied to each of the trained decision trees to obtain a probability of the image element representing a predefined class of organ. The probabilities from each of the decision trees are aggregated and used to assign an organ classification to the image element. In another embodiment, a method of training a decision tree to identify features in an image is provided. For a selected node in the decision tree, a training image is analyzed at a plurality of locations offset from a selected image element, and one of the offsets is selected based on the results of the analysis and stored in association with the node. | 08-04-2011 |
20110228997 | Medical Image Rendering - Medical image rendering is described. In an embodiment a medical image visualization engine receives results from an organ recognition system which provide estimated organ centers, bounding boxes and organ classification labels for a given medical image. In examples the visualization engine uses the organ recognition system results to select appropriate transfer functions, bounding regions, clipping planes and camera locations in order to optimally view an organ. For example, a rendering engine uses the selections to render a two-dimensional image of medical diagnostic quality with minimal user input. In an embodiment a graphical user interface populates a list of organs detected in a medical image and a clinician is able to select one organ and immediately be presented with the optimal view of that organ. In an example opacity of background regions of the medical image may be adjusted to provide context for organs presented in a foreground region. | 09-22-2011 |
20110274352 | Image Segmentation Using Star-Convexity Constraints - Image segmentation using star-convexity constraints is described. In an example, user input specifies positions of one or more star centers in a foreground to be segmented from a background of an image. In embodiments, an energy function is used to express the problem of segmenting the image and that energy function incorporates a star-convexity constraint which limits the number of possible solutions. For example, the star-convexity constraint may be that, for any point p inside the foreground, all points on a shortest path (which may be geodesic or Euclidean) between the nearest star center and p also lie inside the foreground. In some examples continuous star centers such as lines are used. In embodiments a user may iteratively edit the star centers by adding brush strokes to the image in order to progressively change the star-convexity constraints and obtain an accurate segmentation. | 11-10-2011 |
20110293180 | Foreground and Background Image Segmentation - Foreground and background image segmentation is described. In an example, a seed region is selected in a foreground portion of an image, and a geodesic distance is calculated from each image element to the seed region. A subset of the image elements having a geodesic distance less than a threshold is determined, and this subset of image elements are labeled as foreground. In another example, an image element from an image showing at least a user, a foreground object in proximity to the user, and a background is applied to trained decision trees to obtain probabilities of the image element representing one of these items, and a corresponding classification assigned to the image element. This is repeated for each image element. Image elements classified as belonging to the user are labeled as foreground, and image elements classified as foreground objects or background are labeled as background. | 12-01-2011 |
20120207359 | Image Registration - Image registration is described. In an embodiment an image registration system executes automatic registration of images, for example medical images. In an example, semantic information is computed for each of the images to be registered comprising information about the types of objects in the images and the certainty of that information. In an example a mapping is found to register the images which takes into account the intensities of the image elements as well as the semantic information in a manner which is weighted by the certainty of that semantic information. For example, the semantic information is computed by estimating posterior distributions for the locations of anatomical structures by using a regression forest and transforming the posterior distributions into a probability map. In an example the mapping is found as a global point of inflection of an energy function, the energy function having a term related to the semantic information. | 08-16-2012 |
20120239174 | Predicting Joint Positions - Predicting joint positions is described, for example, to find joint positions of humans or animals (or parts thereof) in an image to control a computer game or for other applications. In an embodiment image elements of a depth image make joint position votes so that for example, an image element depicting part of a torso may vote for a position of a neck joint, a left knee joint and a right knee joint. A random decision forest may be trained to enable image elements to vote for the positions of one or more joints and the training process may use training images of bodies with specified joint positions. In an example a joint position vote is expressed as a vector representing a distance and a direction of a joint position from an image element making the vote. The random decision forest may be trained using a mixture of objectives. | 09-20-2012 |
20120269407 | AUTOMATIC ORGAN LOCALIZATION - Automatic organ localization is described. In an example, an organ in a medical image is localized using one or more trained regression trees. Each image element of the medical image is applied to the trained regression trees to compute probability distributions that relate to a distance from each image element to the organ. At least a subset of the probability distributions are selected and aggregated to calculate a localization estimate for the organ. In another example, the regression trees are trained using training images having a predefined organ location. At each node of the tree, test parameters are generated that determine which subsequent node each training image element is passed to. This is repeated until each image element reaches a leaf node of the tree. A probability distribution is generated and stored at each leaf node, based on the distance from the leaf node's image elements to the organ. | 10-25-2012 |
20130223690 | COMPUTING HIGH DYNAMIC RANGE PHOTOGRAPHS - Computing high dynamic range photographs is described for example, to enable high ranges of intensities to be represented in a single image. In various embodiments two or more photographs of the same scene taken at different exposure levels are combined in a way which takes into account intensity or other gradients in the images to form a high dynamic range image. In embodiments geodesic distances (which take into account intensity or other image gradients) are computed and used to form weights for a weighted aggregation of the photographs. In some embodiments a user configurable parameter is operable to control a degree of mixing of the photographs as the high dynamic range image is formed. | 08-29-2013 |
20130343619 | DENSITY ESTIMATION AND/OR MANIFOLD LEARNING - Density estimation and/or manifold learning are described, for example, for computer vision, medical image analysis, text document clustering. In various embodiments a density forest is trained using unlabeled data to estimate the data distribution. In embodiments the density forest comprises a plurality of random decision trees each accumulating portions of the training data into clusters at their leaves. In embodiments probability distributions representing the clusters at each tree are aggregated to form a forest density which is an estimate of a probability density function from which the unlabeled data may be generated. A mapping engine may use the clusters at the leaves of the density forest to estimate a mapping function which maps the unlabeled data to a lower dimensional space whilst preserving relative distances or other relationships between the unlabeled data points. A sampling engine may use the density forest to randomly sample data from the forest density. | 12-26-2013 |
20130346346 | SEMI-SUPERVISED RANDOM DECISION FORESTS FOR MACHINE LEARNING - Semi-supervised random decision forests for machine learning are described, for example, for interactive image segmentation, medical image analysis, and many other applications. In examples, a random decision forest comprising a plurality of hierarchical data structures is trained using both unlabeled and labeled observations. In examples, a training objective is used which seeks to cluster the observations based on the labels and similarity of the observations. In an example, a transducer assigns labels to the unlabeled observations on the basis of the clusters and certainty information. In an example, an inducer forms a generic clustering function by counting examples of class labels at leaves of the trees in the forest. In an example, an active learning module identifies regions in a feature space from which the observations are drawn using the clusters and certainty information; new observations from the identified regions are used to train the random decision forest. | 12-26-2013 |
20140126821 | FOREGROUND AND BACKGROUND IMAGE SEGMENTATION - Foreground and background image segmentation is described. In an example, a seed region is selected in a foreground portion of an image, and a geodesic distance is calculated from each image element to the seed region. A subset of the image elements having a geodesic distance less than a threshold is determined, and this subset of image elements are labeled as foreground. In another example, an image element from an image showing at least a user, a foreground object in proximity to the user, and a background is applied to trained decision trees to obtain probabilities of the image element representing one of these items, and a corresponding classification assigned to the image element. This is repeated for each image element. Image elements classified as belonging to the user are labeled as foreground, and image elements classified as foreground objects or background are labeled as background. | 05-08-2014 |
20140241617 | CAMERA/OBJECT POSE FROM PREDICTED COORDINATES - Camera or object pose calculation is described, for example, to relocalize a mobile camera (such as on a smart phone) in a known environment or to compute the pose of an object moving relative to a fixed camera. The pose information is useful for robotics, augmented reality, navigation and other applications. In various embodiments where camera pose is calculated, a trained machine learning system associates image elements from an image of a scene, with points in the scene's 3D world coordinate frame. In examples where the camera is fixed and the pose of an object is to be calculated, the trained machine learning system associates image elements from an image of the object with points in an object coordinate frame. In examples, the image elements may be noisy and incomplete and a pose inference engine calculates an accurate estimate of the pose. | 08-28-2014 |
20140307956 | IMAGE LABELING USING GEODESIC FEATURES - Image labeling is described, for example, to recognize body organs in a medical image, to label body parts in a depth image of a game player, to label objects in a video of a scene. In various embodiments an automated classifier uses geodesic features of an image, and optionally other types of features, to semantically segment an image. For example, the geodesic features relate to a distance between image elements, the distance taking into account information about image content between the image elements. In some examples the automated classifier is an entangled random decision forest in which data accumulated at earlier tree levels is used to make decisions at later tree levels. In some examples the automated classifier has auto-context by comprising two or more random decision forests. In various examples parallel processing and look up procedures are used. | 10-16-2014 |