Computer Vision Foundations · 免费预览
重建与插值
理想重建用一个频域矩形窗切出一个频谱副本，其空域形状为 sinc，而每种实用的插值器都是对它的廉价局部近似。
1. The ideal is a box, lived as a sinc
The ideal is a box, lived as a sinc
2. One sinc per sample
One sinc per sample
3. The price of the ideal
The price of the ideal
4. The local rogues' gallery
The local rogues' gallery
5. Why each sample owns its point
In sinc reconstruction, every sample plants a scaled sinc centered at itself. Why does the final curve pass exactly through every sample value?
6. Choosing a cheap kernel
An image must be upscaled in real time inside a GPU sampler, where only tiny local kernels are affordable. What is the honest trade among box, triangle, and Lanczos?
7. The sinc at an integer
Write the value of sinc(1), where sinc(t) = sin(πt)/(πt).