| 摘要 |
An image frame is replayed from a store and an operator manually identifies control positions on or near the boundary of an object 301. Pixel values are compared around the control positions to define local colour transitions and the boundary is completed by interpolation. Pairs of image areas near respective control positions are processed to determine colour values, specifically regions in colour space which include the colours within the areas. The region of colour space lying between the identified regions is used to generate a matrix transformation which is operable within RGB colour-space to generate mask blending values between full on and full off. Thus a soft bounded region may be combined with a fill to produce a multi-bit key, matte, alpha or mask layer for selectively removing the foreground or background to allow compositing with images obtained from elsewhere, without the need for recording the foreground against a specific type of background. |
