Abstract: A system for shading graphic images for realistic rendering representative of tarnish accumulation has a display device, a central processing unit, an input device, and a memory means. The memory includes image components, shading routines, accessibility routines, display routines, and a texture map. The system modifies each image prior to display to apply shading. The system uses the accessibility routines to produce an accessibility factor for each pixel in the image. The accessibility factor is then used by the display routines to apply the desired shading to each pixel as it is rendered on the display device.

Abstract: Tabular documents have column structures that can be determined without decoding the bitmap. The method searches for separation intervals that separate word fragments in the table. These separation intervals are processed by intersecting them with other intervals and ranking the resulting intervals. A structured closure of separation intervals are maintained in bins. The intervals in the bins are sorted and used to determine new intersections when the next separation interval is processed. The intervals with the highest ranking are selected as the column separation intervals. The columns are easily identified with the method without first decoding the bitmap.