Abstract: A method and apparatus for painting a digital picture using strokes of a digital brush is provided. The painting strokes entered by a user is handled using a "lazy" processing approach, in which a region of the picture being painted is updated according to the entered strokes only when that region is to be displayed for viewing. To this end, the painting strokes are recorded as an ordered sequence of painting steps. The digital picture being painted is partitioned into a plurality of individual regions, and each region is assigned an age which indicates a painting step in the ordered sequence that is last applied to that region. When a region becomes visible, i.e., it is displayed for viewing, the age of the region is checked, and all of the painting steps in the ordered sequence that are after the step indicated by the age of the region are then applied to the region so that it becomes up-to-date. The age of that region is updated accordingly.