| 摘要 |
PURPOSE: To improve the precision of chromakey processing by approximating color distribution with an optional number of three-dimensional ellipsoidal faces and dividing color space by the use of the ellipsoidal faces to extract a required area. CONSTITUTION: Color information is acquired and the approximate shape of an ellipsoid is determined by the analysis of main components in color distribution. The approximate shape of the ellipsoid is determined by the generating processing of a data array, the calculation of an average value, the preparation of variance/covariance matrix, and the calculation of characteristic values and characteristic vectors. Picture elements to be included in the inside of the ellipsoid and picture elements to be included in its outside are respectively specified and the probability of picture elements to be included in the inside out of all the specified picture elements is applied. A parameter other than a scale coefficient ρ is determined by the use of the picture elements to be included in the inside. While changing the value of the coefficient ρ to be found out by a prescribed evaluation expression is calculated and a scale coefficient ρ minimizing the σ is selected to determined the size of the ellipsoid. The determined ellipsoidal shape is used as a divided shape and applied to chromakey processing. |
