Range cell formation processing

Abstract

A range cell formation process that are used to enhance the quality of an image following a perspective transformation from range-azimuth coordinates (B-scan) into elevation-azimuth coordinates (C-scan). The present range cell formation process eliminate situations where there are missing data points at the far range, and large areas that have the same data point at the near range. The range cell formation process evaluates the data content in range cells on a case by case basis using a prioritized system to determine what is to be displayed so that a high level of image contrast is maintained. In the far range, range cell data that are in between range points defined by every two adjacent elevation points are processed and a priority system is used to determine the best intensity value to use for the elevation points. The priority system is such that bright objects have the highest priority, followed by dark objects, and then followed by an average background level. Range cells are processed to determine which priority is met, and then the appropriate intensity is used. If a bright object is detected in the range cells, then the maximum intensity of the range cells is used. If a dark object is detected, then the lowest intensity of the range cells is used. Otherwise, the average intensity of the range cells is used. In the near range, no enhancements are made to reduce the size of large areas, but the size of bright objects is reduced, thereby providing a sense of increased focus in the near range.