数字图像变换，主要介绍傅立叶变换和余弦变换及其性质-Digital image transform, introduces the Fourier transform and cosine transform and its properties

Coefficients a and b control the low and high frequency ranges that the watermark affects. Because of the watermark invariant properties, we embed the watermark only in the Fourier descr iptor magnitude. We use the inverse Fourier transform of the Fo

基于MATLAB平台的PWM调制正弦波的快速傅里叶分析-his model simulates and computes Fourier analysis of PWM based sinusoidal waveform. Fundamental frequency can be changed in model properties. Amplitude modulation index and frequency modulation index can be adjusted in Sim