Patent ID: 7893950

Claim:
A computer program product, tangibly stored on a computer-readable medium, for compositing digital graphics objects, comprising instructions operable to cause a programmable processor to perform operations including: compositing a transparency group of digital graphics objects on a non-transparent group backdrop to generate an accumulated result, the transparency group including two or more contiguous digital graphics objects in a stack of digital graphics objects, the group backdrop being a result of compositing elements in the stack up to but not including the first element of the transparency group, the compositing of the transparency group including combining colors specified by the group backdrop and one or more digital graphics objects in the transparency group such that the accumulated result includes a contribution of the group backdrop; removing the contribution of the group backdrop from the accumulated result to generate a compositing result for the transparency group, wherein removal of a color contribution of the group backdrop effects a reversal of compositing the group backdrop with a normal blend mode.