计算机工程与应用
計算機工程與應用
계산궤공정여응용
COMPUTER ENGINEERING AND APPLICATIONS
2014年
8期
161-163
,共3页
近似系数%细节系数%9/7小波%小波工具箱
近似繫數%細節繫數%9/7小波%小波工具箱
근사계수%세절계수%9/7소파%소파공구상
approximate coefficient%detail coefficient%9/7 wavelet%wavelet toolbox
对MATLAB中直接采用正交小波计算模型处理双正交小波,导致小波分解系数冗余的问题进行了研究。针对该问题,提出采用9/7小波原型处理非周期信号的改进算法,与MATLAB所给算法相比,对于奇起点的偶数长信号和偶起点的奇数长信号,分解时可少计算2个近似系数和1个细节系数;对于奇起点的奇数长信号和偶起点的偶数长信号,可少计算1个近似系数。当用改进算法分解512×512点图像至第4级时,便可少计算4256个系数,且重构图像的峰值信噪比要高于MATLAB中恢复图像。所以,改进算法既降低了计算量和数据存储量,又提高了恢复图像的质量。
對MATLAB中直接採用正交小波計算模型處理雙正交小波,導緻小波分解繫數冗餘的問題進行瞭研究。針對該問題,提齣採用9/7小波原型處理非週期信號的改進算法,與MATLAB所給算法相比,對于奇起點的偶數長信號和偶起點的奇數長信號,分解時可少計算2箇近似繫數和1箇細節繫數;對于奇起點的奇數長信號和偶起點的偶數長信號,可少計算1箇近似繫數。噹用改進算法分解512×512點圖像至第4級時,便可少計算4256箇繫數,且重構圖像的峰值信譟比要高于MATLAB中恢複圖像。所以,改進算法既降低瞭計算量和數據存儲量,又提高瞭恢複圖像的質量。
대MATLAB중직접채용정교소파계산모형처리쌍정교소파,도치소파분해계수용여적문제진행료연구。침대해문제,제출채용9/7소파원형처리비주기신호적개진산법,여MATLAB소급산법상비,대우기기점적우수장신호화우기점적기수장신호,분해시가소계산2개근사계수화1개세절계수;대우기기점적기수장신호화우기점적우수장신호,가소계산1개근사계수。당용개진산법분해512×512점도상지제4급시,편가소계산4256개계수,차중구도상적봉치신조비요고우MATLAB중회복도상。소이,개진산법기강저료계산량화수거존저량,우제고료회복도상적질량。
MATLAB directly uses orthogonal wavelet calculation model to process biorthogonal wavelet, leading to coef-ficients redundant problem. According to that, this paper proposes 9/7 wavelet prototype as the improved algorithm to hand the nonperiodic signal, compared with the given algorithm in MATLAB, for the signals which have the odd starting-even length and even starting-odd length, after wavelet transformation, two approximate coefficients and one detail coefficient can be saved, for the signals which have the odd starting-odd length and even starting-even length, one approximate coefficient can be saved. When using the improved algorithm to decompose the image with 512×512 points to 4th level, 4256 coefficients can be saved, and reconstruction image’s peak value signal-to-noise ratio is higher than the reconstruction image in MATLAB. So the improved algorithm not only reduces the computation time and data storage capacity, but also improves the quality of the reconstruction image.