Patents by Inventor Li-Qun Xu
Li-Qun Xu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 8494051Abstract: Global motion between frames of a motion-compensated inter-frame encoded video sequence is estimated directly from the motion vectors encoded within the frames. For any particular frame, the motion vectors are first decoded, and a finite number of sets of vectors are selected. An affine or other geometrical transform is then used to generate a motion estimation for each set, and then the least median squared error present in each motion estimation is calculated for each estimation. The motion estimation with the smallest least median squared error is then selected as being representative of the global motion in the image of the frame. A panoramic image generating method and system makes uses of the global motion estimations thus obtained.Type: GrantFiled: November 18, 2003Date of Patent: July 23, 2013Assignee: BRITISH TELECOMMUNICATIONS plcInventors: Yongmin Li, Li-Qun Xu, David G Morrison, Charles Nightingale, Jason Morphett
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Patent number: 8385663Abstract: A method of segmenting a sequence of video images according to scene activity, the method comprising: defining a first series of nodes in a first multi-dimensional space, each node corresponding to an image of the sequence of video images; defining a transformation function that maps each of the first series of nodes to a corresponding node in a second multi-dimensional space having a lower dimensionality than the first multi-dimensional space; applying said transformation function to each of the first series of nodes to define a second series of respective nodes in the second multi-dimensional space; applying a data clustering algorithm to the second series of nodes to identify clusters of nodes within the second multi-dimensional space, the data clustering algorithm being constrained by a measure of feature distance between a pair of clusters of nodes and a measure of temporal distance between the pair of clusters of nodes; determining a representative image from each cluster of nodes and plotting each reprType: GrantFiled: February 27, 2010Date of Patent: February 26, 2013Assignee: BRITISH TELECOMMUNICATIONS public limited companyInventors: Li-Qun Xu, Arasanathan Anjulan
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Patent number: 8311394Abstract: Video data defining a series of images is processed to define a first series of nodes in a first multidimensional space, each of the first series of nodes corresponding to an image of the series of images and its location in the first space defined in dependence on features of the respective image. A transformation function maps each of the nodes in the first multidimensional space onto a respective node in a second lower dimensionality multidimensional space while maintaining neighborhood relationships between nodes. A second series of nodes in the second multidimensional space is defined in accordance with the transformation function and a clustering analysis is performed in dependence on the nodes of the second multidimensional space.Type: GrantFiled: February 21, 2007Date of Patent: November 13, 2012Assignee: British Telecommunications plcInventors: Li-Qun Xu, Bin Luo
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Patent number: 8290040Abstract: The invention relates to estimating the global motion between frames of a motion-compensated inter-frame encoded video sequence, directly from the motion vectors encoded within the frames. For any particular frame, a motion estimation is determined from motion vectors direct from the frame's anchor frame to the frame in question. This motion estimation is then checked against pre-determined criteria, and where the criteria are not met, re-estimation along a different route is performed, using the bi-directional motion vectors contained within B-frames. A panoramic image generating method and system which makes uses of the global motion estimations thus obtained is also described.Type: GrantFiled: November 18, 2003Date of Patent: October 16, 2012Assignee: British Telecommunications public limited companyInventors: Yongmin Li, Li-Qun Xu, David G Morrison, Charles Nightingale, Jason Morphett
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Patent number: 8134596Abstract: In a digital video surveillance system, a number of processing stages are employed to identify foreground regions representing moving objects in a video sequence. An object tracking stage (5) is also provided in order to identify a correspondence between candidate objects in a current frame and those that have already been identified in one or more previous frames. In this way, it is possible to calculate the path taken by the or each foreground object and to record this path information in a trajectory database. In order to improve tracking performance, the object tracking stage (5) employs a state transitional object management scheme which determines whether or not a particular object is tracked. The path information generated by the object tracking stage (5) can be displayed on a video monitor (15) of the surveillance system and/or made available to high level applications (7).Type: GrantFiled: February 6, 2006Date of Patent: March 13, 2012Assignee: BRITISH TELECOMMUNICATIONS public limited companyInventors: Bangjun Lei, Li-Qun Xu
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Publication number: 20110317982Abstract: A method of segmenting a sequence of video images according to scene activity, the method comprising: defining a first series of nodes in a first multi-dimensional space, each node corresponding to an image of the sequence of video images; defining a transformation function that maps each of the first series of nodes to a corresponding node in a second multi-dimensional space having a lower dimensionality than the first multi-dimensional space; applying said transformation function to each of the first series of nodes to define a second series of respective nodes in the second multi-dimensional space; applying a data clustering algorithm to the second series of nodes to identify clusters of nodes within the second multi-dimensional space, the data clustering algorithm being constrained by a measure of feature distance between a pair of clusters of nodes and a measure of temporal distance between the pair of clusters of nodes; determining a representative image from each cluster of nodes and plotting each reprType: ApplicationFiled: February 26, 2010Publication date: December 29, 2011Inventors: Li-Qun Xu, Arasanathan Anjulan
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Publication number: 20110307215Abstract: A distance detection system and method for use in a hand-held electronic device is described. The distance detection system comprises an input unit used to input at least one instruction; at least one processing device having a timing element and a calculating element; at least one signal device; and an air inspecting unit. The signal device is used to transmit a signal to a detecting object in response to the instruction, and to receive a response signal from the detecting object. The timing element is used to measure an interval between transmitting the signal and receiving the response signal. The air inspecting unit is used to detect a condition of air between the hand-held electronic device and the detecting object. The data of the detected air condition can be converted into a parameter to calculate distance data corresponding to a distance from both the parameter and the measured interval.Type: ApplicationFiled: June 1, 2011Publication date: December 15, 2011Applicants: INVENTEC APPLIANCES (SHANGHAI) CO., LTD., INVENTEC APPLIANCES CORP., NANJING, INVENTEC APPLIANCES CORP.Inventor: Li-Qun Xu
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Patent number: 8073197Abstract: A video surveillance system (10) comprises a camera (25), a personal computer (PC) (27) and a video monitor (29). Video processing software is provided on the hard disk drive of the PC (27). The software is arranged to perform a number of processing operations on video data received from the camera, the video data representing individual frames of captured video. In particular, the software is arranged to identify one or more foreground blobs in a current frame, to match the or each blob with an object identified in one or more previous frames, and to track the motion of the or each object as more frames are received. In order to maintain the identity of objects during an occlusion event, an appearance model is generated for blobs that are close to one another in terms of image position.Type: GrantFiled: March 1, 2006Date of Patent: December 6, 2011Assignee: BRITISH TELECOMMUNICATIONS public limited companyInventors: Li-Qun Xu, Pere Puig Folch
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Publication number: 20110275407Abstract: The present invention provides a mobile phone including: a casing; a first battery disposed inside the casing; a control module disposed inside the casing; and a signal converting module movably connected to the casing and including: a second battery; and a converting unit for converting at least one wireless signal into at least one 3rd-generation signal; wherein the converting unit is disabled by the control module when the signal converting module is connected to the casing; and the converting unit is enabled by the control module when the signal converting module is detached from the casing.Type: ApplicationFiled: April 7, 2011Publication date: November 10, 2011Applicants: INVENTEC APPLIANCES (SHANGHAI) CO. LTD., INVENTEC APPLIANCES CORP., NANJING, INVENTEC APPLIANCES CORP.Inventor: LI-QUN XU
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Patent number: 8041075Abstract: In a digital video surveillance system, a number of processing stages are employed to identify foreground regions representing moving objects in a video sequence. An object tracking stage 5 is also provided in order to identify a correspondence between candidate objects in a current frame and those that have already been identified in one or more previous frames. In this way, it is possible to calculate the path taken by the or each foreground object and to record this path information in a trajectory database. In order to improve tracking performance, the object tracking stage 5 employs a state transitional object management scheme which determines whether or not a particular object is to be tracked. As part of the object management scheme, spurious objects, which are identified on the basis of their motion characteristics, are deleted from the system. This ensures that valuable processing resources are not wasted tracking unwanted artifacts which may represent, for example, noise or random motion.Type: GrantFiled: February 6, 2006Date of Patent: October 18, 2011Assignee: British Telecommunications public limited companyInventors: Bangjun Lei, Li-Qun Xu
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Patent number: 8009897Abstract: The invention provides a method and apparatus for performing correspondence estimation between pixels of a stereo image pair to obtain matching information for corresponding pixels in each image. To perform a match for a particular pixel in a first image firstly an adaptive curve is constructed about the pixel, being a sequence of connected pixels with similar intensity values to the pixel being matched. The adaptive curve thus constructed is then used as a matching element within the second image to find a matching pixel representative of the same 3D scene point in the second image to the particular pixel. By performing matching in this manner for every pixel in an image, accurate disparity maps can be obtained which are then used in a known image synthesis algorithm to produce novel images of a scene of improved quality.Type: GrantFiled: October 4, 2002Date of Patent: August 30, 2011Assignee: British Telecommunications public limited companyInventors: Li-Qun Xu, Bangjun Lei
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Patent number: 7978917Abstract: In an intelligent video surveillance system, video processing software performs a number of operations on video data received from a camera, including foreground extraction, shadow removal and object tracking. The foreground extraction stage classifies each pixel of a received frame as representing either foreground or background. Since shadow regions can be wrongly classified as foreground, a two-branch shadow removal operation is employed, comprising weak shadow removal (32) and strong shadow removal (33). The purpose of weak shadow removal (32) is to remove only the most severe shadows in each frame. Conversely, the purpose of strong shadow removal (33) is to remove substantially every shadow present in each frame. By comparing the overlap of foreground regions in the two resulting images, it is possible to identify foreground regions that have fragmented due to strong shadow removal, and thereafter classify them as representing a common foreground object.Type: GrantFiled: October 24, 2005Date of Patent: July 12, 2011Assignee: British Telecommunications public limited companyInventors: Bangjun Lei, Li-Qun Xu
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Patent number: 7949050Abstract: A shot-based video content analysis method and system is described for providing automatic recognition of logical story units (LSUs). The method employs vector quantization (VQ) to represent the visual content of a shot, following which a shot clustering algorithm is employed together with automatic determination of merging and splitting events. The method provides an automated way of performing the time-consuming and laborious process of organising and indexing increasingly large video databases such that they can be easily browsed and searched using natural query structures.Type: GrantFiled: March 17, 2005Date of Patent: May 24, 2011Assignee: British Telecommunications public limited companyInventors: Li-Qun Xu, Sergio Benini
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Publication number: 20100322516Abstract: Embodiments of the present invention relate to automated methods and systems for analysing crowd congestion in a physical space. Video images are used to define a region of interest (205) in the space and partition the region of interest into an irregular array of sub-regions (220), to each of which is assigned a congestion contributor. Then, first and second spatial-temporal visual features are determined, and metrics are computed (225), (245), to characterise a degree of dynamic or static congestion in each sub-region. The metrics and congestion contributors are used to generate (260) an indication of the overall measure of congestion within the region of interest.Type: ApplicationFiled: February 19, 2009Publication date: December 23, 2010Inventors: Li-Qun Xu, Arasanathan Anjulan
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Publication number: 20100316257Abstract: Embodiments of the present invention relate to automated methods and systems for determining a degree of presence of a movable object in a physical space. Video images are used to define a region of interest (1305) in the space and partition the region of interest into an array of sub-regions (1310). Then, first and second spatial-temporal visual features are determined, and metrics are computed (1320), (1340), to characterise whether or not each sub-region contains a moving or stationary object. The metrics are used to generate (1350) an indication of the overall degree of presence within the region of interest.Type: ApplicationFiled: February 19, 2009Publication date: December 16, 2010Applicant: BRITISH TELECOMMUNICATIONS PUBLIC LIMITED COMPANYInventors: Li-Qun Xu, Arasanathan Anjulan
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Publication number: 20100309331Abstract: An electronic device and a photographing method thereof are provided. The photographing method of the electronic device includes the following steps. Whether an intelligent photographing function is active is determined, and a current air pressure is detected while the intelligent photographing function is active. Whether the current air pressure is greater than a predetermined air pressure is determined, and a frame is captured while the current air pressure is greater than the predetermined air pressure.Type: ApplicationFiled: June 9, 2010Publication date: December 9, 2010Applicant: Inventec Appliances Corp.Inventor: Li-Qun Xu
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Publication number: 20100291913Abstract: A remote control method between mobile phones is provided for making a connection between a first mobile phone and a second mobile phone through a telephone exchange apparatus, so that the mobile phones can manipulate each other without a distance restriction and execute multiple commands. The first mobile phone sends a representative code identifying the second mobile phone to the telephone exchange apparatus, the telephone exchange apparatus examines the representative code to obtain information of the second mobile phone, and sends a message of connection to the second mobile phone, for asking to connect the second mobile phone with the first mobile phone. If the second mobile phone permits connection with the first mobile phone, the telephone exchange apparatus assigns a virtual IP address for connecting to the second mobile phone, and the first mobile phone uses the virtual IP address to connect to the second mobile phone.Type: ApplicationFiled: May 14, 2010Publication date: November 18, 2010Applicant: INVENTEC APPLIANCES CORP.Inventor: Li-Qun Xu
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Publication number: 20100240395Abstract: A positioning method of a wireless communication device includes the steps of: receiving first and second wireless signals from the first and second base stations of first and second networks time of transmitting the first and second wireless signals from the first and second base stations to the wireless communication device respectively; determining first and second domains capable of receiving the first and second wireless signals; obtaining a coordinate of one intersection point of the first and second domains; and integrating the coordinate of the intersection point and a geographical data base to obtain a geographical position of the wireless communication device.Type: ApplicationFiled: March 10, 2010Publication date: September 23, 2010Inventor: Li-Qun XU
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Patent number: 7742650Abstract: A segmentation operation is applied to an input image to identify foreground objects of interest, and then a shadow removal operation is applied to remove any detected shadows from the foreground segmentation. The shadow removal algorithms can leave holes and bisections in the segmentation map, however, which will then subsequently impact on an object detection step performed using connected component analysis. To get around this problem, a conditional morphological dilation operation is applied to the segmentation map to ‘grow’ the segmented blobs to fill in any holes and bisections, without re-growing shadow pixels in the segmentation. The result is an object detection method and system which is robust to illumination changes causing shadows and/or highlights.Type: GrantFiled: November 8, 2004Date of Patent: June 22, 2010Assignee: British Telecommunications plcInventors: Li-Qun Xu, Jose-Luis Landabaso
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Publication number: 20100150403Abstract: A video signal is analysed by deriving for each frame a plurality of parameters, said parameters including (a) at least one parameter that is a function of the difference between picture elements of that frame and correspondingly positioned picture elements of a reference frame; (b) at least one parameter that is a function of the difference between picture elements of that frame and correspondingly positioned picture elements of a previous frame; and (c) at least one parameter that is a function of the difference between estimated velocities of picture elements of that frame and the estimated velocities of the correspondingly positioned elements of an earlier frame. Based on these parameters, each frame is assigned one or more of a plurality of predetermined classifications. Scene changes may then be identified as points at which changes occur in these classification assignments.Type: ApplicationFiled: January 17, 2007Publication date: June 17, 2010Inventors: Andrea Cavallaro, Li-Qun Xu