题目 ： http://www.imageprocessingplace.com/DIP-3E/dip3e_student_projects.htm#03-01
图片：http://www.imageprocessingplace.com/root_files_V3/image_databases.htm
实现内容：
- Two-Dimensional Fast Fourier Transform
- Fourier Spectrum and Average Value
- Lowpass Filtering
- Highpass Filtering