说明：  Gabor滤波器的原理是 其脉冲响应为一个谐波函数（即下式中的余弦函数）和一个高斯函数的乘积。根据信号与系统理论，时频域的卷积和乘积互为傅里叶变换。Gabor滤波器的傅里叶变换为谐波和高斯函数各自傅里叶变换的卷积
(The principle of the Gabor filter is a harmonic of its impulse response function (i.e., the cosine function in the formula) and the product of a Gaussian function. According to the theory of signals and systems, time and frequency domain convolution product of the Fourier transform each other. Fourier transform of the Gabor filter and Gaussian function is the harmonic each convolution of the Fourier transform)