Picture feature extraction system and picture quality evaluation system
| Title: | Picture feature extraction system and picture quality evaluation system |
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| Patent Number: | 7,385,627 |
| Publication Date: | June 10, 2008 |
| Appl. No: | 10/901186 |
| Application Filed: | July 29, 2004 |
| Abstract: | This invention is intended to reduce a line rate of a monitoring line necessary for transmission of a picture feature without complicating a system. A video signal xi (n0, n1) of each block is subjected to spread spectrum by multiplying the video signal xi(n0, n1) by a PN sequences SPN1 (n0, n1) (in a step S1). The resultant video signal is orthogonally transformed by DFT, DCT, WHT, or the like (in a step S2). An amplitude component Ai=|Xi(SE0, SE1)| of an arbitrary component (SE0, SE1) in a coefficient Xi(S0, S1) obtained by the steps S1 and S2 is extracted (in a step S3), and the extracted amplitude component is quantized with a step size M (in a step S4). The picture feature F[i] is given as a residue obtained under a modulus Nm of a quantized typical value obtained by the quantization (in the step S4) (in a step S5). |
| Inventors: | Sugimoto, Osamu (Saitama, JP); Kawada, Ryoichi (Saitama, JP); Koike, Atsushi (Saitama, JP) |
| Assignees: | KDDI Corporation (Tokyo, JP) |
| Claim: | 1. A picture feature extraction system comprising: spread spectrum and orthogonal transform means for iterating spread spectrum and orthogonal transform to a video signal, divided into a plurality of blocks of an arbitrary size, once or an arbitrary times; quantizing means for quantizing an amplitude component of an arbitrary component in an orthogonal transform coefficient output from the spread spectrum and orthogonal transform means with a predetermined step size; and extracting means for extracting a picture feature of a finite bit length by obtaining a residue under a modulus of a quantized typical value output from the quantizing means. |
| Claim: | 2. The picture feature extracting system according to claim 1 , wherein the spread spectrum and orthogonal transform means performs the spread spectrum and Walsh-Hadamard transform. |
| Claim: | 3. A picture quality evaluation system for evaluating a picture quality degradation caused by video transmission, by allowing a transmitting end and a receiving end to extract picture feature, respectively, and by allowing an evaluation section to compare the extracted picture feature of the transmitting end and the receiving end with each other, wherein each of the transmitting end and the receiving end comprises: spread spectrum and orthogonal transform means for iterating spread spectrum and orthogonal transform to a video signal, divided into a plurality of blocks of an arbitrary size, once or an arbitrary times; quantizing means for quantizing an amplitude component of an arbitrary component in an orthogonal transform coefficient output from the spread spectrum and orthogonal transform means with a predetermined step size; and extracting means for extracting a picture feature of a finite bit length by obtaining a residue of a quantized typical value output from the quantizing means, and the evaluation section comprises: means for calculating a value corresponding to a difference in the picture feature of an equal frame and an equal block, for the picture feature extracted by the transmitting end and the receiving end for each block; and evaluating means for evaluating a picture quality of a received picture based on a predetermined relationship between a degree of picture quality degradation defined from a distribution ratio of the difference value of the image feature in a frame and the picture quality index. |
| Claim: | 4. The picture quality evaluating system according to claim 3 , wherein the spread spectrum and orthogonal transform means perform the spread spectrum and Walsh-Hadamard transform. |
| Claim: | 5. The picture quality evaluating system according to claim 3 , wherein a step size of the quantizing means and a quantized typical value can be variably set. |
| Current U.S. Class: | 348/192 |
| Patent References Cited: | 7123741 October 2006 Ono 7149324 December 2006 Tanaka 7231062 June 2007 Zhang et al. 2002/0176002 November 2002 Kawada et al. 2002-247606 August 2002 2003-009186 January 2003 2003-087823 March 2003 |
| Primary Examiner: | Lee, M. |
| Attorney, Agent or Firm: | Westerman, Hattori, Daniels & Adrian, LLP. |
| Accession Number: | edspgr.07385627 |
| Database: | USPTO Patent Grants |
| Language: | English |
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