一种用于图像编码的双正交插值小波

Biorthogonal Interpolating Wavelet for Image Coding

针对CDF-9/7小波滤波器系数是无理数的缺点,利用小波滤波器的精确重构条件,构造一类仅用一个自由参数表达的双正交插值小波。通过调整自由参数构造一种具有最佳编码增益和二进制(形如k/2n,k,n∈Z的数)系数的插值小波。实验表明其图像压缩性能与CDF-9/7小波相当,小波变换的计算效率提高50%以上。

Aiming at the disadvantage of the state-of-the-art CDF-9/7 wavelet that its filter coefficients are irrational, a class of Biorthogonal Interpolating Wavelets（BIW） parameterized by one free parameter is constructed based on the perfect reconstruction of the wavelet filter bank. By adjusting the free parameter, a new BIW is obtained, which has the advantages of both optimum coding gain and binary filter coefficients （numbers of the form k / 2^n, k, n∈ Z ）. Simulations show that the new wavelet exhibits image compression performance competitive to CDF-9/7, and the corresponding lifting based Discrete Wavelet Transform（DWT） gains improvement upon computing efficiency superior to 50%.