基于小波域分形编码的图像插值

传统的图像插值方案(包括最近邻插值、双线性插值和B样条插值等),大多是基于图像分块的光滑连续模型。由于该模型不能很好地描述自然图像的特点,因此插值得到的图像质量不高。为寻求更有效的插值方案,首次提出了基于小波域分形编码的插值算法。该算法在FW编码的基础上,首先利用图像的局部自相似模型,通过小波树的膨胀,并借助小波域的第1级子带,对超分辨率级的第0级子带进行最优预测,再经过小波反变换来得到插值图像。标准测试图像的实验表明,该插值算法与传统的双线性插值相比,不仅可以获得清晰的纹理和边缘,而且峰值信噪比也更高,因此插值得到的图像更加精确、真实。

Image Interpolation Using Wavelet-fractal Coding

The traditional image interpolation involving zeroth-order,bilinear,and cubic spline interpolation mostly depends on a piece-wise continuous and smooth modeling of image.In view of the ability to capture the feature of natural image connected with the modeling,the quality of interpolated image is not desirable.A new interpolation algorithm based on the wavelet-fractal(FW)coding is proposed with more efficient interpolation strategy.By the aid of the local self-similarity modeling of image,the new interpolation algorithm using FW coding is implemented by the dilation of tree wavelet.The super-resolution zeroth subband is optimized predicted by the first subband in the wavelet domain.And then the interpolated image can be obtained by the inverse wavelet transform.The experiments of the standard images suggest that the new algorithm can obtain distinct texture and edge of the images and higher peak signal-to-noise ratio(PSNR)compared with the traditional bilinear strategy.As a result,the image interpolated by the new algorithm is accurate and real.