| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method and system for circularly symmetric anisotropic filtering over an extended ellipse or rectangle in single-pass digital image warping. <P>SOLUTION: The filtering is performed by first finding and adjusting an ellipse that approximates a non-uniform image scaling function in a mapped position of an output pixel in the input image space. A linear transformation from this ellipse to a unit circle in the output image space calculates input pixel radii inside the footprint and corresponding filter coefficient as a function of the radius. The shape of the footprint is determined as a trade-off between image quality and processing speed. In one implementation, profiles of individual smoothing and warping components are combined to produce a sharper or detail enhanced output image. The method and system of the invention produces natural output image without jagged artifacts, while maintaining or enhancing the sharpness of the input image. <P>COPYRIGHT: (C)2012,JPO&INPIT |
