正六边形离散余弦变换图像编码

本文介绍一种六边形离散余弦变换(HDCT)图像编码方法,并将该方法应用于图像编码,对不同图像分别以不同的子图大小及各种编码速率进行模拟实验,给出了实验结果,并作了详尽的分析。

Hexagonal Discrete Cosine Transform lmage Coding

An image coding algorithm using hexagonal discrete cosine transform (HDCT) is presented. The original image is segmented to subimages in the form of hexagonal blocks instead of rectangular ones. the HDCT is taken on the subimag- es. Then, the frequency coefficients are quantized by a Lcoyd-Max quantizer. Following the quantizer is the inversed HDCT. In order to lessen the correlation- ship between the neighbouring subimages, the low frequency part is removed from the image before the HDCT procedure is performed. At present, the images are rectangular arrays instead of hexagonal arrays. Such images can not be processed directly by the HDCT image coder. Before the coding procedure, the images arr- ays shonld be transformed to hexagonal arrays and inversely transformed to the rectangular arrays after the coding procedure. The coding algorithm has been applied to two head-and-shoulder images to test the coding scheme.