Computer Vision Foundations · 免费预览
「Gabor」滤波器
以高斯为窗的复指数构成一个方向带通滤波器，其变换是移离原点的高斯——这是时频联合局部化的最优，也是皮层简单细胞的模型。
1. A wave inside a window
A wave inside a window
2. The spectrum is a Gaussian that moved house
The spectrum is a Gaussian that moved house
3. Sigma trades space for frequency
Sigma trades space for frequency
4. The cortex got there first
The cortex got there first
5. Where the spectrum lands
A Gabor filter is built from a Gaussian times a complex exponential at frequency (u0, v0). Where does its Fourier transform put its energy?
6. Choosing sigma for a task
A texture inspection system must detect small defects that break a fine stripe pattern, and the defects span only a few pixels. What sigma should its Gabor filters use?
7. Frequency spread under doubling
A Gabor's spatial sigma is doubled while its carrier frequency is unchanged. Write the factor by which its frequency spread changes, as a number.