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EP0439334A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Motion analysis system

Assignee: Fujitsu Ltd
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Filing: 1991-01-23
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Granted: —
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Expires: 2011-01-23
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Abstract

Abstract In a motion analysis system utilizing an image processing technique, the system includes: at least one color marker (24) attached to an object (10) to be analyzed, each color marker having a high directivity reflective member on a surface thereof, and the reflection member reflecting light having a special wavelength to a direction of an irradiated light; a light source (14) for generating light to be irradiated onto the color marker; a color TV camera (16) arranged in the same direction as that of the light source, for picking up the color marker and outputting a color image; a color extraction unit (18) operatively connected to the TV camera, and only extracting a particular color from the color image produced by the TV camera; an area calculation unit (261) operatively connected to the color extraction unit, and calculating the area of the particular color extracted by the color extraction unit; a diaphragm adjustment unit (28) operatively connected between the TV camera and the area calculation unit, and adjusting the diaphragm of the TV camera so as to make the area calculated by the area calculation unit with the actual color area of the color marker; and a center of gravity calculation unit (262) operatively connected to the area calculation unit, and calculating a position of the center of gravity of the particular color based on the area calculated by the area calculation unit.

Inventors

  • 👤 Satoshi Naoi
  • 👤 Tohru Ozaki

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-10-30 00:22
CPC Classifications
H; H04; H04N; H04N9/00; H04N9/64; H04N9/74; G; G01; G01S; G01S3/00; G01S3/78; G01S3/782; G01S3/785; G01S3/786; G01S3/7864; G06; G06T; G06T7/00; G06T7/20; H04N5/00; H04N5/222; H04N5/262; H04N5/2625

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 213 words
A motion analysis system comprising: at least one color marker (24) attached to an object (10) to be analyzed, each color marker having a high directivity reflective member on a surface thereof, and the reflective member reflecting light having a special wavelength; a light source (14) for generating light to be irradiated onto the color marker; a color TV camera (16) arranged in the same direction as the light source, and picking up the color marker and outputting a color image; color extraction means (18) operatively connected to the TV camera, and only extracting a particular color from the color image produced by the TV camera; area calculation means (261) operatively connected to the color extraction means, and calculating the area of the particular color extracted by the color extraction means; diaphragm adjustment means (28) operatively connected between the TV camera and the area calculation means, and adjusting the diaphragm of the TV camera so as to make the area calculated by the area calculation means coincide with the actual color area of the color marker; and center of gravity calculation means (262) operatively connected to the area calculation means, and calculating a position of the center of gravity of the particular color based on the area calculated by the area calculation means.
Claim 2
Dependent Claim 30 words
A motion analysis system as claimed in claim 1, wherein said color marker is formed as a spherical body having the high directivity reflective member attached on the surface thereof.
Claim 3
Dependent Claim 30 words
A motion analysis system as claimed in claim 1, wherein said color marker is formed by a polygonal body having the high directivity reflective member attached on the surface thereof.
Claim 4
Dependent Claim 48 words
A motion analysis system as claimed in any of claims 1-4, wherein said color extraction means comprises a look-up table (181) for data conversion from R, G, B signals to particular color bits, R, G, B signals being input from the TV camera through an analog-to-digital converter (30).
Claim 5
Dependent Claim 40 words
A motion analysis system as claimed in claim 4, wherein said look-up table outputs a bit "1" when a particular color indicating the color of the color marker is detected, and outputs a bit "0" when another color is detected.
Claim 6
Dependent Claim 44 words
A motion analysis system as claimed in any preceding claim, wherein said area calculation means comprises a particular color extraction circuit (2631), and a projection amount calculation circuit (2632) for calculating the area of the particular color projected to the horizontal and vertical directions.
Claim 7
Dependent Claim 104 words
A motion analysis system as claimed in any preceding claim, wherein said center of gravity calculation means comprises a digital signal processor (DSP) associated with a host computer, and the digital signal processor has section decision means (341) for deciding the section width for the calculation of the center of gravity in accordance with the size of the object, section projection calculation means (342) for calculating the projection amount in the section, section selection means (343) for selecting the section indicating the maximum projection amount, and section center of gravity calculation means (344) for calculating the center of the gravity at the selected section.
Claim 8
Dependent Claim 52 words
A motion analysis system as claimed in claim 7, wherein said digital signal processor further comprises an external random access memory (RAM), the RAM storing a horizontal projection value, a vertical projection value, a projection valid section, a section width, a maximum section projection, and a position of the center of gravity.
Claim 9
Dependent Claim 39 words
A motion analysis system as claimed in claim 7 or 8, wherein said section selection means provides two kinds of the section, and selects one of two kinds the section so as to include the object within one section.
Claim 10
Dependent Claim 43 words
A motion analysis system as claimed in claim 7, wherein said section selection means has a function of enlarging a section width so as to completely include an object within one section when the object is found to be included in two sections.

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