离散余弦变换(DCT)是一种广泛应用于信号处理、图像处理领域的重要工具,并已被多个国际标准所接受。将DCT应用到实际系统中的前提是具有能够快速实现的算法。给出了一种基于DFT的DCT/IDCT的实现,它避免了变换序列长度的限制。由于DFT可以由FFT实现,所以这种实现方式进而利用到FFT的优势。在满足输入序列长度满足一定条件的情况下,对所提出的算法做了进一步的优化,使得DCT的实现更加容易。 Discrete Cosine Transform (DCT) is an important tool widely used in signal processing, image processing and has been accepted by many international standards. The premise for applying DCT to real systems is to have algorithms that can be implemented quickly. An implementation of DCT / IDCT based on DFT is given, which avoids the limitation of transform sequence length. Since DFT can be implemented by FFT, this implementation takes advantage of FFTs. The proposed algorithm is further optimized under the condition of satisfying the input sequence length, which makes the realization of DCT easier.