Abstract: A layer based paint system permits painting of an image raster of a composite image while viewing subsequent processing on the image raster. The composite image is mapped to an image processing tree. Each of the elements in the image processing tree are defined by an associated data structure that identifies their parent and children elements in the tree. Each of the elements may be, for example, an image element or a process element. Associated with each image element is an image raster and a transform. Viewing and painting of an image element may be done at any level in the image processing tree. Painting of the element directly modifies the pixels in the image raster. The pixel coordinates of brush strokes in the viewed image are transformed into pixel coordinates of the image raster material by applying the inverse transform of the viewed layer, the image element layer and all of the intermediate layers to the pixel coordinates of the brush strokes.