适合高频子带特征的小波域图像放大算法  

Image Magnification Algorithm in Wavelet Domain Adapted for Characteristics of High Frequency Subbands

作　　者：李庆忠[1] 陈静[1] 

机构地区：[1]中国海洋大学工程学院山东省海洋工程重点实验室,山东青岛266100

出　　处：《计算机工程》2017年第7期268-273,共6页Computer Engineering

基　　金：国家自然科学基金(61132005);海洋公益性行业科研专项(201505002)

摘　　要：针对小波域图像放大出现的伪吉普斯现象和虚假边缘问题,提出一种新的小波域图像放大算法。对原始图像进行一级小波变换,根据各高频子带的方向特点,确定高频子带系数在放大子带中的布放位置。给出基于边缘方向的高频系数插值方法,计算空白像素的高频系数。将线性变换的原始图像作为放大后的低频子带,结合放大后的3个高频子带进行小波反变换,得到基于小波变换的放大图像。实验结果表明,该算法可有效克服由于小波变换缺乏平移不变性造成的伪吉普斯现象,避免产生虚假边缘。In order to suppress Pseudo-Gibbs phenomena and remove false edges in image magnification of Wavelet domain,an image magnification algorithm in Wavelet domain is presented. After the original image is decomposed by one level Wavelet transform,an accurate location and placement method of high frequency coefficients in magnified high frequency subbands is given according to the orientation characteristic of high frequency subbands. An edge direction based interpolation method is proposed to determine the value of high frequency coefficient at the blank spaces of pixels.The magnified image is obtained by inversing Wavelet transform on the above magnified three high frequency subbands,and the magnified lowfrequency subband generated by linear transform of the original image. Experimental results showthat the proposed algorithm can effectively remove the Pseudo-Gibbs phenomena due to the shift variance characteristic of wavelet transform,and avoid the generation of false edges.

关 键 词：图像放大 小波变换 高频子带放大 伪吉普斯现象 虚假边缘 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]