Stability Guarantee of All-Pass Multi-Dimensional Variable Fractional-Delay Filter and High-Accuracy Image Interpolation

在各种数字信号处理(DSP)应用中都需要图像内插。例如，如果想要提高图像的分辨率，必须使用图像内插器对图像进行内插。一个实际的例子是数码相机中使用的变焦操作，其中图像分辨率将被频繁地调整。在这项研究中，我们开发了一种新的内插技术，它利用一种新型的数字滤波器--可变分数延迟(VFD)滤波器来实现高精度的图像内插。只要设计出精确的全通VFD滤波器，就可以实现比传统的线性插值法和三次插值法更精确的图像内插。

Image interpolation is required in various digital signal processing(DSP) applications. For example, if one wants to increase the resolution of an image, an image interpolator must be used to interpolate the image. A practical example is the zooming operation used in digital camera, where the image resolution is to be frequently adjusted. In this research, we developed a new interpolation technique that utilizes a new type of digital filter called variable fractional-delay(VFD) filter to achieve high-accuracy image interpolation. As long as an accurate all-pass VFD filter can be designed, more accurate image interpolation than the conventional methods like linear interpolation and cubic interpolation can be achieved.