Discrete Cosine Transform (DCT) Coefficient Distribution

1. What is DCT coefficients?
2. What do you mean by DFT Discrete Fourier Transform discuss the difference of it with DCT discrete cosine transform?
3. What does the discrete cosine transform do?

What is DCT coefficients?

DCT coefficient (0,0) is the DC coefficient, or average sample value. Since natural images tend to vary only slightly from sample to sample, low frequency coefficients are typically larger values and high frequency coefficients are typically smaller values. The 8×8 DCT is defined in Figure 5.21.

What do you mean by DFT Discrete Fourier Transform discuss the difference of it with DCT discrete cosine transform?

Like the discrete Fourier transform (DFT), a DCT operates on a function at a finite number of discrete data points. The obvious distinction between a DCT and a DFT is that the former uses only cosine functions, while the latter uses both cosines and sines (in the form of complex exponentials).

What does the discrete cosine transform do?

The discrete cosine transform (DCT) helps separate the image into parts (or spectral sub-bands) of differing importance (with respect to the image's visual quality). The DCT is similar to the discrete Fourier transform: it transforms a signal or image from the spatial domain to the frequency domain (Fig 7.8).