1.了解离散傅立叶变换及离散余弦变换的基本原理；
2.掌握进行FFT及逆变换的方法；
3.了解图像在频域中处理方法，应用MATLAB语言作简单的低通滤波器。
-1. Understand the discrete Fourier transform and discrete cosine transform the basic principle; 2. master for FFT and inverse transform; 3. understanding of image processing in the frequency domain method, MATLAB language for simple low-pass filter.
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