Precise Edge-directed LWP- SPIHT Encoding for Visual Measuring Image

In order to achieve sparse representation and capture more geometrical features of visual measuring image, a predicted method of edge information based on gray gradient direction is proposed first. Due to the precise positioning of edge, the method of combination of Lifting Wavelet Packet (LWP) transformation and general wavelet packet transformation is adopted to decompose the whole measuring image. Then the designed cost function maintained the integrity of edge information efficiently, that is the sum of energy mean of every sub-band and direction information. Finally, parent-child conflict of wavelet packet transformation in Set Partitioning In Hierarchical Trees (SPIHT) encoding is completed and resolved. By the test of distant view image, nearby view image, partial enlarged image and target image, the compression method for visual measuring image based on edge-directed LWP transformation SPHT encoding (LWP-SPIHT), preserved edge information of visual measuring image and enhanced the reconstructed quality and precision.