6.11 Bitmap Pyramiding

Bitmap pyramiding can produce high-quality pyramids in certain cases where traditional pyramiding is not adequate.

For most raster data types, image pyramiding as described in Image Pyramiding: Parallel Generation and Partial Update results in pyramids of great quality. However, for bitmap rasters of points, lines, or polylines, which are typically stored in 1-bit cell depth, the same pyramiding approach may not create high-quality pyramids. Distorted point patterns and dashed lines are commonly seen in those pyramids.

To solve such problems, you can use the SDO_GEOR.generateBitmapPyramid procedure, instead of SDOGEOR.generatePyramid, to perform pyramiding on bitmap GeoRaster objects. The SDO_GEOR.generateBitmapPyramid procedure significantly improves the pyramid quality by avoiding distorted patterns, particularly dashed lines or missing lines in a bitmap raster, such as a road raster map or utility network raster map.