Patents by Inventor Fang-Chen Chang

Fang-Chen Chang 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).

  • Patent number: 9917988
    Abstract: A method and apparatus for occlusion area detection based on block difference associated with a motion vector and a predicted block difference are disclosed. For each current block of a frame, motion estimation is performed based on a temporally previous frame and a temporally subsequent frame. Based on the motion vector derived, two reference blocks of the current block are located in the temporally neighboring frames. The block difference between these two reference blocks is calculated for the current block. By comparing the block difference with a predicted block difference of the current block, the current block is determined to be an occlusion block or not accordingly. The predicted block difference is updated by averaging the block difference of neighboring blocks in a non-motion boundary area.
    Type: Grant
    Filed: April 9, 2014
    Date of Patent: March 13, 2018
    Assignee: MEDIATEK INC.
    Inventors: Hung-Chi Fang, Fang-Chen Chang
  • Patent number: 9563960
    Abstract: A method and apparatus for foreground detection by designating one of two non-occlusion areas as the foreground area according to results of position matching using two given motion vectors. The detection is performed by matching the position of the current occlusion area in the current frame with one or more positions of a previous occlusion area in a previous frame. The matching operation is based on motion vectors determined for the neighboring areas adjacent to the current occlusion area. The determination of the motion vectors are based on two neighboring frames temporally located before and after the current frame. If the position of the current occlusion area is matched with the previous occlusion area by using one of the motion vectors, the neighboring area corresponding to the motion vector is designated as a foreground area.
    Type: Grant
    Filed: April 9, 2014
    Date of Patent: February 7, 2017
    Assignee: MEDIATEK INC
    Inventors: Hung-Chi Fang, Fang-Chen Chang, Yu-Jen Chen
  • Publication number: 20150296102
    Abstract: A method and apparatus for occlusion area detection based on block difference associated with a motion vector and a predicted block difference are disclosed. For each current block of a frame, motion estimation is performed based on a temporally previous frame and a temporally subsequent frame. Based on the motion vector derived, two reference blocks of the current block are located in the temporally neighboring frames. The block difference between these two reference blocks is calculated for the current block. By comparing the block difference with a predicted block difference of the current block, the current block is determined to be an occlusion block or not accordingly. The predicted block difference is updated by averaging the block difference of neighboring blocks in a non-motion boundary area.
    Type: Application
    Filed: April 9, 2014
    Publication date: October 15, 2015
    Applicant: MEDIATEK INC.
    Inventors: Hung-Chi Fang, Fang-Chen Chang
  • Publication number: 20150294179
    Abstract: A method and apparatus for foreground detection by designating one of two non-occlusion areas as the foreground area according to results of position matching using two given motion vectors. The detection is performed by matching the position of the current occlusion area in the current frame with one or more positions of a previous occlusion area in a previous frame. The matching operation is based on motion vectors determined for the neighboring areas adjacent to the current occlusion area. The determination of the motion vectors are based on two neighboring frames temporally located before and after the current frame. If the position of the current occlusion area is matched with the previous occlusion area by using one of the motion vectors, the neighboring area corresponding to the motion vector is designated as a foreground area.
    Type: Application
    Filed: April 9, 2014
    Publication date: October 15, 2015
    Applicant: MEDIATEK INC.
    Inventors: Hung-Chi Fang, Fang-Chen Chang, Yu-Jen Chen
  • Patent number: 8644379
    Abstract: A luminance compensating method of compensating a de-interlaced pixel in a current block of a current frame with reference to a reference block of a reference frame is provided. First, calculate an average luminance of the current block and an average luminance of the reference block. Next, adjust the luminance of the de-interlaced pixel by a luminance difference between the average luminance of the current block and the average luminance of the reference block, such that the luminance of the de-interlaced pixel is more appropriate and the display quality is improved.
    Type: Grant
    Filed: March 7, 2007
    Date of Patent: February 4, 2014
    Assignee: Himax Technologies Limited
    Inventor: Fang-Chen Chang
  • Patent number: 8488676
    Abstract: A method for estimating the motion vector for a current macroblock within a current frame is provided by reference to a number of reference macroblocks within the previous frame. The method includes the following steps. First, an error between the current macroblock within a current frame and each of the reference macroblocks is determined according to a weighted sum of absolute differences (SAD) operation. The weighted SAD operation is to emphasize the absolute differences for high-frequency pixels within the current macroblock. Next, the reference macroblock having the lowest error may be determined as a matched macroblock. Finally, the motion vector for the current macroblock can be defined as the displacement between the macroblock and the matched macroblock.
    Type: Grant
    Filed: May 14, 2007
    Date of Patent: July 16, 2013
    Assignee: Himax Technologies Limited
    Inventor: Fang-Chen Chang
  • Patent number: 8391372
    Abstract: A method for doubling the frame rate of video signals creates an interpolated video frame using a current frame and a previous frame. First, the current frame is sequentially received. The interpolated frame is inserted between a previous frame and the current frame, in which values for each pixel in the interpolated frame are derived from a first reference pixel in the current frame biased by a positively weighted difference between the first reference pixel and a second reference pixel in the previous frame.
    Type: Grant
    Filed: May 16, 2007
    Date of Patent: March 5, 2013
    Assignee: Himax Technologies Limited
    Inventor: Fang Chen Chang
  • Patent number: 8358850
    Abstract: An edge direction determination method for a pixel of a display picture. The display picture has a corresponding edge map. The pixel has corresponding pixel direction pairs. First, in step (a), it is judged whether the pixel is an edge pixel according to the edge map. Next, in step (b), it is judged whether the pixel has a right-inclined edge direction or a left-inclined edge direction when the pixel is the edge pixel. Then, in step (c), the edge direction of the pixel is determined according to specific pixel direction pairs corresponding to the same inclined edge direction if a judged result in step (b) is affirmative. Finally, in step (d), if the judged result in step (b) is negative, it is judged whether the pixel has a horizontal edge direction or a vertical edge direction.
    Type: Grant
    Filed: September 20, 2007
    Date of Patent: January 22, 2013
    Assignee: Himax Technologies Limited
    Inventor: Fang-Chen Chang
  • Patent number: 8325271
    Abstract: A method of frame interpolation for frame rate up conversion method is provided. The method includes: determining a first adjusting value and a second adjusting value according to a target pixel in at least one of a first frame and a second frame; determining an interpolated pixel value of the target pixel in an interpolated frame between the first frame and the second frame according to the first adjusting value and a pixel value of the target pixel in one of the first and second frames; and adjusting a pixel value of the target pixel in one of the first and second frames according to the second adjusting value.
    Type: Grant
    Filed: June 12, 2007
    Date of Patent: December 4, 2012
    Assignee: Himax Technologies Limited
    Inventors: Ling-Hsiu Huang, Fang-Chen Chang
  • Patent number: 8111750
    Abstract: A method for 3-D recursive search motion estimation is provided to estimate a motion vector for a current block in a current frame. The method includes the following steps. First, provide a spatial prediction by selecting at least one motion vector for at least one neighboring block in the current frame. Then, provide a temporal prediction. After that, estimate the motion vector for the current block based on the spatial prediction and the temporal prediction. The temporal prediction is obtained by selecting at least one most frequent motion vector from a plurality of motion vectors for a plurality of blocks in a corresponding region of a previous frame, wherein the corresponding block encloses a previous block which is location corresponding to the current block in the current frame.
    Type: Grant
    Filed: March 20, 2007
    Date of Patent: February 7, 2012
    Assignee: Himax Technologies Limited
    Inventor: Fang-Chen Chang
  • Patent number: 8054381
    Abstract: An apparatus for frame rate up conversion comprises a motion-compensated frame rate converter, a primitive frame rate converter and a determination circuit. The determination circuit designates either the motion-compensated frame rate converter or the primitive frame rate converter to output an interpolated frame according to an index that estimates an output quality of the motion-compensated frame rate converter.
    Type: Grant
    Filed: May 17, 2007
    Date of Patent: November 8, 2011
    Assignee: Himax Technologies Limited
    Inventor: Fang Chen Chang
  • Patent number: 8031953
    Abstract: An encoding method to encode image data comprising a sequence of blocks with a predetermined compression rate in one pass is disclosed. The blocks are divided into two sets, a first set and a second set. The blocks in the first set are encoded within the sum of an available bit length and a predetermined lending bit length. The blocks are encoded in the second set within the available bit length. A lending bit length is updated when the current bit length is larger than the available bit length. The left bit length is updated when the current bit length is not larger than the available bit length. The left bit length and the lending bit length are adjusted when the current block is in the second set, the lending bit length is positive and the left bit length is larger than a predetermined threshold.
    Type: Grant
    Filed: October 18, 2007
    Date of Patent: October 4, 2011
    Assignee: Himax Technologies Limited
    Inventor: Fang-Chen Chang
  • Patent number: 8014612
    Abstract: The disclosed image processing device receiving image data comprises a first encoder, a second encoder and an encoding switch. The first encoder generates first data by encoding the image data according to a predetermined method. The second encoder generates second data by encoding the image data according to an encoding pattern table. The encoding pattern table is set up in accordance with the first data. The encoding switch determines to output either the first data or the second data as an encoded result and generates a mark value for indicating the encoded result.
    Type: Grant
    Filed: October 12, 2007
    Date of Patent: September 6, 2011
    Assignee: Himax Technologies Limited
    Inventor: Fang-Chen Chang
  • Patent number: 8013936
    Abstract: A de-interlacing method is applied to a to-be-de-interlaced field including display pixels of display lines and to-be-interpolated pixels of to-be-interpolated lines. First, a corresponding edge-direction value of each of edge pixels in the to-be-de-interlaced field is determined. Next, it is judged whether one of the display pixels near each to-be-interpolated pixel has a corresponding edge-direction value so that a judgement result is obtained. Then, a corresponding edge-direction value of each to-be-interpolated pixel is set according to the corresponding edge-direction values of specific display pixels of the display pixels near the to-be-interpolated pixel if the judgement result is affirmative. Finally, a corresponding display pixel pair of up and down display lines near each to-be-interpolated pixel is selected according to the corresponding edge-direction value of each to-be-interpolated pixel so that a luminance value and a chrominance value of the to-be-interpolated pixel are calculated.
    Type: Grant
    Filed: June 25, 2007
    Date of Patent: September 6, 2011
    Assignee: Himax Technologies Limited
    Inventor: Fang-Chen Chang
  • Patent number: 7876968
    Abstract: An apparatus for compressing an image data with an array of pixels comprising a data length is disclosed. The apparatus comprises a rearranging unit, a transformation operator, a quantizer and a coding operator. The rearranging unit is configured to transform the array to form a rearranged block with a mark value. The transformation operator is configured to obtain transform coefficients of the rearranged block according to a predetermined transformation. The quantizer is configured to quantize the transform coefficients. The coding operator is configured to generate a result data by coding the transform coefficients which is quantized and the mark value according to a predetermined coding method.
    Type: Grant
    Filed: October 15, 2007
    Date of Patent: January 25, 2011
    Assignee: Himax Technologies Limited
    Inventor: Fang-Chen Chang
  • Patent number: 7844124
    Abstract: A method of estimating a quantization parameter is provided. The method is applied to a de-blocking filter. The de-blocking filter de-blocks a decoded block-based image according to the quantization parameter, and the block-based image is coded and decoded in units of macroblocks. The method comprises calculating blocking degrees of a number of block edges corresponding to the macroblocks; and estimating the quantization parameter according to a sum of the blocking degrees.
    Type: Grant
    Filed: May 11, 2007
    Date of Patent: November 30, 2010
    Assignee: Himax Technologies Limited
    Inventor: Fang-Chen Chang
  • Patent number: 7728910
    Abstract: The invention relates to a 2D YC separation device and YC separation system for separating a composite signal into a luma signal (Y) and a chroma signal (C). Firstly, the 2D YC separation device utilizes a low-pass filter to separate the composite signal into a low-frequency composite signal and a high-frequency composite signal. The low-frequency composite signal is a low-frequency luma signal. A 2D comb filter is utilized to separate the high-frequency composite signal into a high-frequency luma signal and the chroma signal. The luma signal is equal to the low-frequency luma signal plus the high-frequency luma signal. Therefore, the 2D YC separation device of the present invention can perfectly separate the composite signal so as to obtain a better luma signal and chroma signal. The YC separation system of the present invention further comprises a 3D YC separation device and a motion detection device, so as to obtain a precise luma signal and chroma signal.
    Type: Grant
    Filed: May 23, 2006
    Date of Patent: June 1, 2010
    Assignee: Himax Technologies, Inc.
    Inventor: Fang-Chen Chang
  • Publication number: 20090238198
    Abstract: A packing switching system and method is disclosed. A pipelined processor processes image pixels to generate a number of bit streams. Subsequently, a packing unit packs the bit streams into packets in a way that the bit stream or streams with minimum pixel order number are packed before other bit stream or streams.
    Type: Application
    Filed: March 20, 2008
    Publication date: September 24, 2009
    Inventors: Sheng-Chun Niu, Fang-Chen Chang, Shih-Chuan Lu, Ling-Hsiu Huang
  • Publication number: 20090180033
    Abstract: A frame rate up conversion method is disclosed. The method includes the steps of receiving a first reference frame and a second reference frame, and determining a first part in a new video frame according to the first reference frame, the second reference frame, and a second part in the new video frame. The second part includes an already-generated pixel area lying in the new video frame. An apparatus for performing the method is also disclosed.
    Type: Application
    Filed: January 11, 2008
    Publication date: July 16, 2009
    Inventor: Fang-Chen Chang
  • Publication number: 20090103820
    Abstract: An encoding method to encode image data comprising a sequence of blocks with a predetermined compression rate in one pass is disclosed. The blocks are divided into two sets, a first set and a second set. The blocks in the first set are encoded within the sum of an available bit length and a predetermined lending bit length. The blocks are encoded in the second set within the available bit length. A lending bit length is updated when the current bit length is larger than the available bit length. The left bit length is updated when the current bit length is not larger than the available bit length. The left bit length and the lending bit length are adjusted when the current block is in the second set, the lending bit length is positive and the left bit length is larger than a predetermined threshold.
    Type: Application
    Filed: October 18, 2007
    Publication date: April 23, 2009
    Applicant: HIMAX TECHNOLOGIES LIMITED
    Inventor: Fang-Chen Chang