Weather-Huffman Method of Data Compression of Weather Images

摘要

The Weather-Huffman (WH) Algorithm developed in this report incorporates several211u001esubalgorithms in order to encode as faithfully as possible an input weather image 211u001ewithin a specified datalink bit limitation. The main algorithm component is the 211u001eencoding of a version of the input image via the Weather Huffman runlength code, 211u001ea variant of the standard Huffman code tailored to the peculiarities of weather 211u001eimages. Two routines are included in WH to overcome these problems. The first is 211u001ea Smoother Process, which corrects the blocky edges of weather regions. The 211u001esecond, more powerful routine, is the Extra Bit Algorithm (EBA). EBA utilizes ass 211u001ebits remaining in the massage after the Huffman encoding to correct pixels set at 211u001etoo high a weather level. Both size and shape of weather regions are adjusted by 211u001ethis algorithm. Pictorial examples of the operation of this algorithm on several 211u001esevere weather images derived from NEXRAD are presented.