Interpolation filter design based on all-phase DST and its application to image demosaicking
Interpolation filter design based on all-phase DST and its application to image demosaicking
复制标题
基于全相位DST的插值滤波器设计及其在图像去马赛克中的应用
作者：
Xiao Zhou;Chengyou Wang;Zhi Zhang;Qiming Fu
本文在深入理解全相位数字滤波器（APDF）设计和全相位双正交变换（APBT）的基础上，进一步研究了加窗全相位数字滤波器（WAPDF）和加窗全相位双正交变换（WAPBT），讨论了加窗全相位双正交变换（WAPBT）的原理，给出了统一的全相位变换（APT）构造方法。基于一种类型的正交变换，即，基于离散正弦变换（DST），构造了一种插值滤波器--全相位DST（APDST）滤波器，并将其用于图像去马赛克，将其与双线性插值和全相位逆离散余弦变换（APIDCT）插值滤波器进行比较，测试其在图像插值中的性能，并进行分析和讨论。实验结果表明，大小为7 × 7的APIDCT和APDST滤波器的插值性能相当，但优于双线性插值方法。本文设计的低通滤波器除了用于图像插值去马赛克之外，还可以广泛应用于图像插值、图像去噪、图像去噪等图像处理领域。
Based on a deep understanding of all-phase digital filter (APDF) design and all-phase biorthogonal transform (APBT), this paper will further study the windowed all-phase digital filter (WAPDF) and windowed all-phase biorthogonal transform (WAPBT), discuss the principle of the WAPBT, and provide a unified construction method of the all-phase transform (APT). Based on a type of orthogonal transform, i.e., discrete sine transform (DST), an interpolation filter called an all-phase DST (APDST) filter is constructed and used for image demosaicking; it is compared with bilinear interpolation and all-phase inverse discrete cosine transform (APIDCT) interpolation filters, to test its performance in image interpolation and provide analysis and discussion. The experimental results show that APIDCT and APDST filters with a size of 7 × 7 are similar in interpolation performance, but better than the bilinear interpolation method. In addition to its use in image interpolation demosaicking, the low-pass filter designed in this paper can also be widely used in image interpolation, image denoising, image resizing, and other fields of image processing.