Patents Assigned to Snell & Wilcox
  • Image Segmentation
    Publication number: 20080037870
    Abstract: A method of image segmentation using graph-theory techniques, in which pixels of an image are represented by the vertices of a graph. A minimum spanning tree is generated and edges of the tree are successively removed according to a morphological property to leave a spanning forest, trees of which correspond to segments of the image. Selection of edges for removal may depend on an energy function of a tree and on the energy function of trees created by removal of that edge.
    Type: Application
    Filed: November 25, 2005
    Publication date: February 14, 2008
    Applicant: SNELL & WILCOX LIMITED
    Inventors: Michael Knee, Martin Weston
  • Sport Action Coding
    Publication number: 20070198906
    Abstract: A method of compressing data representing a sequence of images in dependence upon data defining at least one region of particular interest within at least one image in the sequence includes causing data representing an image region that is not of particular interest to be more highly compressed than data representing an image regions that is of particular interest.
    Type: Application
    Filed: February 13, 2007
    Publication date: August 23, 2007
    Applicant: SNELL & WILCOX LIMITED
    Inventor: Michael Knee
  • METHOD OF AND APPARATUS FOR IMAGE ANALYSIS
    Publication number: 20070081741
    Abstract: A method of and apparatus for image analysis for picture loss detection in fields or frames in video or film content makes use of different correlation characteristics of picture images and non-picture images to detect picture loss. A measure of self correlation of a plurality of image data samples, and a measure of the correlation of the plurality of image data samples with a mean value are determined, and a positive detection of picture loss is based on a comparison between the two correlation measures.
    Type: Application
    Filed: September 6, 2006
    Publication date: April 12, 2007
    Applicant: SNELL & WILCOX LIMITED
    Inventors: Jonathan Diggins, Martin Weston
  • Video signal processing with two stage motion compensation
    Patent number: 7202909
    Abstract: In motion compensated standards conversion, an output video field is constructed from four input fields (two inner fields and two outer fields) by shifting pixel information from an outer field to the output field position in two stages, the first stage using a first motion vector between the outer field and the adjacent inner field and the second stage using a second motion vector being derived from a motion vector pointing from one inner field to the other inner field.
    Type: Grant
    Filed: March 23, 2001
    Date of Patent: April 10, 2007
    Assignee: Snell & Wilcox Limited
    Inventor: Andrew Major
  • Video compression
    Patent number: 7164715
    Abstract: In compression coding of picture sequences, a measure of picture difference is generated and compared with a picture difference threshold. The comparison is used in selecting between the use of predicted (P-pictures) and non-predicted has an initial value adapted to promote the use of an I-picture at or close to a scene change in the picture sequence, and changes in time in such a manner as to increase the probability of selection of a I-picture with an increase in the time since selection of the last I-picture.
    Type: Grant
    Filed: July 27, 2001
    Date of Patent: January 16, 2007
    Assignee: Snell & Wilcox Limited
    Inventor: Michael James Knee
  • Video signal processing
    Patent number: 7161635
    Abstract: A method of de-interlacing a video signal by conducting three linear filtering operations on the input to produce three filtered signals, each linear filtering operation comprising the taking of a weighted sum of pixels; and multiplying together the three filtered signals to produce an output video signal.
    Type: Grant
    Filed: May 17, 1999
    Date of Patent: January 9, 2007
    Assignee: Snell & Wilcox Limited
    Inventors: Martin Weston, William Beningfield Collis
  • Video signal processing
    Patent number: 7027104
    Abstract: In video scratch repair, scratches are treated as additive pedestals which are constant or slowly changing along the scratch. For a given picture, these pedestals are estimated and subtracted from the video input to reveal original picture detail. The pedestal can be estimated by heavily filtering along the direction of the presumed scratch, the output of a prior art scratch detector.
    Type: Grant
    Filed: March 26, 2001
    Date of Patent: April 11, 2006
    Assignee: Snell & Wilcox Limited
    Inventors: Martin Weston, William Beningfield Collis
  • Data compression unit control for alignment of output signal
    Patent number: 7023925
    Abstract: To enable a single programme in a multiple programme MPEG transport stream (MPTS) to be replaced seamlessly by a locally generated programme, the local coder received the MPTS as a reference signal and outputs transport packets in alignment with the packets of the programme to be replaced. Timing and other packet parameters are also copied.
    Type: Grant
    Filed: October 11, 1999
    Date of Patent: April 4, 2006
    Assignee: Snell & Wilcox Limited
    Inventor: Graham Ward
  • Video signal processing
    Patent number: 7009656
    Abstract: In video processing, a motion compensated process and an equivalent linear process are performed on an input signal, the processing errors of which are computed and compared. The comparison is then used to control a mix between the outputs of the two processes to produce an output signal.
    Type: Grant
    Filed: April 9, 2001
    Date of Patent: March 7, 2006
    Assignee: Snell & Wilcox Limited
    Inventors: Roderick M. Thomson, David M. Banks
  • Data compression unit control for alignment of output signal
    Publication number: 20060034375
    Abstract: To enable a single programme in a multiple programme MPEG transport stream (MPTS) to be replaced seamlessly by a locally generated programme, the local coder receives the MPTS as a reference signal and outputs transport packets in alignment with the packets of the programme to be replaced. Timing and other packet parameters are also copied.
    Type: Application
    Filed: October 6, 2005
    Publication date: February 16, 2006
    Applicant: Snell & Wilcox Limited
    Inventor: Graham Ward
  • Spatial video processing
    Patent number: 6950560
    Abstract: In video signal processing, diagonal lines or slopes are detected in the input material, and an adaptive spatial filter having positive, negative and linear filter apertures is employed. The positive filter aperture is employed upon detection of any positive slopes in excess of a defined positive threshold; the negative filter upon detection of negative slopes, and the linear filter otherwise.
    Type: Grant
    Filed: April 4, 2001
    Date of Patent: September 27, 2005
    Assignee: Snell & Wilcox Limited
    Inventor: Martin Weston
  • Video signal processing
    Patent number: 6922214
    Abstract: Motion between adjacent fields of an interlaced video signal is analyzed by vertically interpolating the current field to produce a line signal which corresponds in vertical position with lines from the succeeding and preceding fields; and subtracting the signals to provide a field difference. The effect of vertical detail is reduced by comparing two field differences or by subtracting a local or global detail signal from the field difference.
    Type: Grant
    Filed: November 3, 1999
    Date of Patent: July 26, 2005
    Assignee: Snell & Wilcox Limited
    Inventor: Martin Weston
  • Method and apparatus for blocking effect reduction
    Patent number: 6898321
    Abstract: By utilizing parameters derivable from a compressed bit-stream, measures are obtained of the subjective quality of a decoded picture, without the necessity for reference to source material. A blockiness measure is derived both locally and globally and used to control a de-blocking filter. An estimate of signal-to-noise ratio is derived from quantization values.
    Type: Grant
    Filed: October 11, 1999
    Date of Patent: May 24, 2005
    Assignee: Snell & Wilcox Limited
    Inventors: Michael James Knee, Jonathan Diggins
  • Analysis of compression decoded video image sequences
    Patent number: 6895049
    Abstract: A method of detecting I-frames in a video signal which has previously been MPEG coded, involves taking a DCT and analyzing the frequency of zero value coefficients. An I-frame, which does not utilize prediction coding is expected to have a higher number of zero coefficients than a predicted P- or B-frame.
    Type: Grant
    Filed: October 11, 1999
    Date of Patent: May 17, 2005
    Assignee: Snell & Wilcox Limited
    Inventors: Michael James Knee, Ian James Poole
  • Bit rate control for video data compression
    Patent number: 6865224
    Abstract: In MPEG2 encoding, the quantiser is controlled to manage the occupancy of a video buffer. A dynamically varying working range is determined by forecasting from recent coding history the number of bits required in coding of future pictures, and deriving upper and lower ends of the working range which correspond respectively with attainment within the forecast period of predetermined maximum and minimum buffer occupancies. The quantiser scale is then controlled through the position of the actual buffer occupancy within that working range.
    Type: Grant
    Filed: January 28, 2000
    Date of Patent: March 8, 2005
    Assignee: Snell & Wilcox Limited
    Inventors: Michael James Knee, Emma Gottesman
  • Video signal processing using triplets of pixels
    Patent number: 6700623
    Abstract: A de-interlacing process takes a weighted sum of pixels in a filter aperture to generate a pixel in an output picture, the weighted sum including products of triplets of pixels. Using a training sequence of progressive material, it is possible to calculate the weighting coefficients necessary to minimize the mean square error between the filter output and the desired result.
    Type: Grant
    Filed: July 26, 2000
    Date of Patent: March 2, 2004
    Assignee: Snell & Wilcox Limited
    Inventors: Martin Weston, William Beningfield Collis
  • Video process where part of compressed version of video signal accompanies video signal itself
    Patent number: 6674802
    Abstract: After decoding of an MPEG bitstream to the form of a video signal, an information stream signal in the form of all or part of the MPEG bitstream, is transmitted alongside the video signal, embedded in the least significant bit. Recording may simply involve extraction of the embedded MPEG bitstream or, if only part of the bitstream has been embedded, an essentially “dumb” coding operation guided by the information stream signal.
    Type: Grant
    Filed: August 26, 1999
    Date of Patent: January 6, 2004
    Assignees: Snell & Wilcox Limited, British Broadcasting Corporation
    Inventors: Michael James Knee, Nicholas Dominic Wells
  • Display with input mechanisms
    Patent number: D562318
    Type: Grant
    Filed: April 15, 2005
    Date of Patent: February 19, 2008
    Assignee: Snell & Wilcox
    Inventor: Murray Ward
  • Keyboard for control desk
    Patent number: D562322
    Type: Grant
    Filed: April 15, 2005
    Date of Patent: February 19, 2008
    Assignee: Snell & Wilcox
    Inventor: Murray Ward
  • Control panel
    Patent number: D565046
    Type: Grant
    Filed: April 15, 2005
    Date of Patent: March 25, 2008
    Assignee: Snell & Wilcox
    Inventor: Murray Ward