Abstract: A user interface is described for an image computing workstation for electronically arranging the components of a special effects job, such as image-compositing, from a plurality of image sequences obtained by the scanning of motion picture film. The interface controls the ordering of a plurality of image sequences into a hierarchy of background and foreground image sequences, with each sequence being composed of frames whose appearance imitates the frames of a motion picture film. The hierarchical image sequences are displayed adjacent to each other in a windowing environment so that the frames thereof visually align on a frame-to-frame basis. The interface includes means for varying the hierarchical order and the adjacency of the image sequences so that different frames thereof are brought into visual alignment with each other, whereby the image sequences are correctly ordered as to hierarchy and adjacency for a special effect.