Patents by Inventor Jiandan Chen

Jiandan Chen 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).

  • Publication number: 20220351485
    Abstract: A device and method merge a first candidate area relating to a candidate feature in a first image and a second candidate area relating to a candidate feature in a second image. The first and second images have an overlapping region, and at least a portion of the first and second candidate areas are located in the overlapping region. An image overlap size is determined indicating a size of the overlapping region of the first and second images, and a candidate area overlap ratio is determined indicating a ratio of overlap between the first and second candidate areas. A merging threshold is then determined based on the image overlap size, and, on condition that the candidate area overlap ratio is larger than the merging threshold, the first candidate area and the second candidate area are merged, thereby forming a merged candidate area.
    Type: Application
    Filed: April 11, 2022
    Publication date: November 3, 2022
    Applicant: Axis AB
    Inventors: Jiandan CHEN, Hanna BJÖRGVINSDÓTTIR, Ludvig PETTERSSON
  • Publication number: 20220254178
    Abstract: A method for updating a coordinate of an annotated point in a digital image due to camera movement is performed by an image processing device, which obtains a current digital image of a scene. The current digital image has been captured by a camera subsequent to movement of the camera relative the scene. The current digital image is associated with at least one annotated point. Each at least one annotated point has a respective coordinate in the current digital image. The method comprises identifying an amount of the movement by comparing position indicative information in the current digital image to position indicative information in a previous digital image of the scene. The previous digital image has been captured prior to movement of the camera. The method comprises updating the coordinate of each at least one annotated point in accordance with the identified amount of movement and a camera homography.
    Type: Application
    Filed: December 16, 2021
    Publication date: August 11, 2022
    Applicant: Axis AB
    Inventors: Jiandan CHEN, Haiyan XIE
  • Publication number: 20220180105
    Abstract: A tag for indicating a region of interest, ROI, has a predefined format and codes ROI information, which is readable by imaging the tag and which includes a size indication and a relative position indication, the respective indications allowing the ROI's size and position to be determined relative to the tag's size and position. A method for locating a ROI in an image comprises: obtaining an image; searching in the image for a tag with the predefined format; and determining a ROI on the basis of the tag's size and position in the image and the ROI information. A method for generating a tag comprises: obtaining an image including a visible provisional tag of same physical size as the tag to be generated; obtaining operator input identifying a ROI in the image; deriving the size indication and relative position indication; and printing the tag.
    Type: Application
    Filed: November 15, 2021
    Publication date: June 9, 2022
    Applicant: Axis AB
    Inventors: Jiandan CHEN, Haiyan XIE
  • Patent number: 10552737
    Abstract: Methods and apparatus, including computer program products, implementing and using techniques for configuring an artificial neural network to a particular surveillance situation. A number of object classes characteristic for the surveillance situation are selected. The object classes form a subset of the total number of object classes for which the artificial neural network is trained. A database is accessed that includes activation frequency values for the neurons within the artificial neural network. The activation frequency values are a function of the object class. Those neurons having activation frequency values lower than a threshold value for the subset of selected object classes are removed from the artificial neural network.
    Type: Grant
    Filed: December 21, 2017
    Date of Patent: February 4, 2020
    Assignee: Axis AB
    Inventors: Robin Seibold, Jiandan Chen, Hanna Björgvinsdóttir, Martin Ljungqvist
  • Patent number: 10147200
    Abstract: Methods and apparatus, including computer program products, implementing and using techniques for classifying an object occurring in a sequence of images. The object is tracked through the sequence of images. A set of temporally distributed image crops including the object is generated from the sequence of images. The set of image crops is fed to an artificial neural network trained for classifying an object. The artificial network determines a classification result for each image crop. A quality measure of each classification result is determined based on one or more of: a confidence measure of a classification vector output from the artificial neural network, and a resolution of the image crop. The classification result for each image crop is weighed by its quality measure, and an object class for the object is determined by combining the weighted output from the artificial neural network for the set of images.
    Type: Grant
    Filed: March 21, 2017
    Date of Patent: December 4, 2018
    Assignee: Axis AB
    Inventors: Hanna Bjorgvinsdottir, Jiandan Chen
  • Publication number: 20180276845
    Abstract: Methods and apparatus, including computer program products, implementing and using techniques for classifying an object occurring in a sequence of images. The object is tracked through the sequence of images. A set of temporally distributed image crops including the object is generated from the sequence of images. The set of image crops is fed to an artificial neural network trained for classifying an object. The artificial network determines a classification result for each image crop. A quality measure of each classification result is determined based on one or more of: a confidence measure of a classification vector output from the artificial neural network, and a resolution of the image crop. The classification result for each image crop is weighed by its quality measure, and an object class for the object is determined by combining the weighted output from the artificial neural network for the set of images.
    Type: Application
    Filed: March 21, 2017
    Publication date: September 27, 2018
    Inventors: Hanna Bjorgvinsdottir, Jiandan Chen
  • Publication number: 20180181867
    Abstract: Methods and apparatus, including computer program products, implementing and using techniques for configuring an artificial neural network to a particular surveillance situation. A number of object classes characteristic for the surveillance situation are selected. The object classes form a subset of the total number of object classes for which the artificial neural network is trained. A database is accessed that includes activation frequency values for the neurons within the artificial neural network. The activation frequency values are a function of the object class. Those neurons having activation frequency values lower than a threshold value for the subset of selected object classes are removed from the artificial neural network.
    Type: Application
    Filed: December 21, 2017
    Publication date: June 28, 2018
    Applicant: Axis AB
    Inventors: Robin Seibold, Jiandan Chen, Hanna Björgvinsdóttir, Martin Ljungqvist
  • Patent number: 9936217
    Abstract: A method and encoder for video encoding a sequence of frames is provided. The method comprises: receiving a sequence of frames depicting a moving object, predicting a movement of the moving object in the sequence of frames between a first time point and a second time point; defining, on basis of the predicted movement of the moving object, a region of interest (ROI) in the frames which covers the moving object during its entire predicted movement between the first time point and the second time point; and encoding a first frame, corresponding to the first time point, in the ROI and one or more intermediate frames, corresponding to time points being intermediate to the first and the second time point, in at least a subset of the ROI using a common encoding quality pattern defining which encoding quality to use in which portion of the ROI.
    Type: Grant
    Filed: November 25, 2015
    Date of Patent: April 3, 2018
    Assignee: AXIS AB
    Inventors: Jiandan Chen, Markus Skans, Willie Betschart, Mikael Pendse, Alexandre Martins
  • Patent number: 9830528
    Abstract: A method may include determining a value indicative of an average intensity of blocks in an image. The blocks include a primary and outer blocks. Each of the outer blocks may have three, five, or more than five pixels. The image may describe an external pixel lying between the primary and at least one of the outer blocks. The external pixel may not contribute to the value indicative of the average intensity of any of the blocks. The image may also describe a common internal pixel lying within two of the blocks. The common pixel may contribute to the value indicative of the average intensity of the two of the blocks. The method may include comparing the value indicative of the average intensity of the primary block to the values of the outer blocks, and quantifying a feature represented by the image by generating a characteristic number.
    Type: Grant
    Filed: December 9, 2015
    Date of Patent: November 28, 2017
    Assignee: Axis AB
    Inventors: Jiandan Chen, Anders Lloyd, Niclas Danielsson
  • Publication number: 20170169306
    Abstract: A method may include determining a value indicative of an average intensity of blocks in an image. The blocks include a primary and outer blocks. Each of the outer blocks may have three, five, or more than five pixels. The image may describe an external pixel lying between the primary and at least one of the outer blocks. The external pixel may not contribute to the value indicative of the average intensity of any of the blocks. The image may also describe a common internal pixel lying within two of the blocks. The common pixel may contribute to the value indicative of the average intensity of the two of the blocks. The method may include comparing the value indicative of the average intensity of the primary block to the values of the outer blocks, and quantifying a feature represented by the image by generating a characteristic number.
    Type: Application
    Filed: December 9, 2015
    Publication date: June 15, 2017
    Inventors: Jiandan Chen, Anders Lloyd, Niclas Danielsson
  • Patent number: 9536154
    Abstract: A method of monitoring a scene by a camera (7) comprises marking a part (14) of the scene with light having a predefined spectral content and a spatial verification pattern. An analysis image is captured of the scene by a sensor sensitive to the predefined spectral content. The analysis image is segmented based on the predefined spectral content, to find a candidate image region. A spatial pattern is detected in the candidate image region, and a characteristic of the detected spatial pattern is compared to a corresponding characteristic of the spatial verification pattern. If the characteristics match, the candidate image region is identified as a verified image region corresponding to the marked part (14) of the scene. Image data representing the scene is obtained, and image data corresponding to the verified image region is processed in a first manner, and remaining image data is processed in a second manner.
    Type: Grant
    Filed: May 8, 2014
    Date of Patent: January 3, 2017
    Assignee: Axis AB
    Inventors: Markus Skans, Anders Johannesson, Jiandan Chen, Joakim Baltsen
  • Publication number: 20160165257
    Abstract: A method and encoder for video encoding a sequence of frames is provided. The method comprises: receiving a sequence of frames depicting a moving object, predicting a movement of the moving object in the sequence of frames between a first time point and a second time point; defining, on basis of the predicted movement of the moving object, a region of interest (ROI) in the frames which covers the moving object during its entire predicted movement between the first time point and the second time point; and encoding a first frame, corresponding to the first time point, in the ROI and one or more intermediate frames, corresponding to time points being intermediate to the first and the second time point, in at least a subset of the ROI using a common encoding quality pattern defining which encoding quality to use in which portion of the ROI.
    Type: Application
    Filed: November 25, 2015
    Publication date: June 9, 2016
    Applicant: AXIS AB
    Inventors: Jiandan Chen, Markus Skans, Willie Betschart, Mikael Pendse, Alexandre Martins
  • Publication number: 20140334676
    Abstract: A method of monitoring a scene by a camera (7) comprises marking a part (14) of the scene with light having a predefined spectral content and a spatial verification pattern. An analysis image is captured of the scene by a sensor sensitive to the predefined spectral content. The analysis image is segmented based on the predefined spectral content, to find a candidate image region. A spatial pattern is detected in the candidate image region, and a characteristic of the detected spatial pattern is compared to a corresponding characteristic of the spatial verification pattern. If the characteristics match, the candidate image region is identified as a verified image region corresponding to the marked part (14) of the scene. Image data representing the scene is obtained, and image data corresponding to the verified image region is processed in a first manner, and remaining image data is processed in a second manner.
    Type: Application
    Filed: May 8, 2014
    Publication date: November 13, 2014
    Applicant: Axis AB
    Inventors: Markus SKANS, Anders Johannesson, Jiandan Chen, Joakim Baltsen