| 摘要 |
<p>The estimated subject color and/or the estimated background color for a given pixel will have a certain amount of error, which could result in either not enough background removal, or removal of all of the background and some of the foreground. Manual alteration of a subject or background color is achieved by using a cursor to select a true color from the background, and inserting it in one or more areas in the background area being partially obscured by the subject. Automatic alteration of one of the estimated subject or background colors involves its computations as a projection in color space of the observed transition pixel color, onto a plane defined by the subject and background reference colors. By treating the shadow (3) as semitransparent subject, a matte (alpha channel) may be generated (8) to represent the shadow's transition densities, thus permitting the shadow to be generated over the new background (11).</p> |
