True Fourier transform is one of the most important transforms that is used in Digital signal Processing and Image Processing. Fourier transform gave a new direction and understanding to digital Signal Processing and Image Processing.

When light is passed through a prism, it gets split into different colours known as spectrum. The colours that we see are VIBGYOR. It means that while light is actually made up of these 7 colours. The prism splits while light into separate colours. The prism transforms the light using Fourier transform. This is splitting of signals into its component signals. Fourier transform states that any function that periodically repeats itself can be expressed as the sum of sines and cosines of different frequencies and different amplitudes. Hence the Fourier transform is nothing but a mathematical prism. It can be said that the original signal is composed of infinite frequencies of varying amplitudes and the Fourier transform tell us about aperiodic signals. Since most of signals and images that we encounter over a finite duration over all aperiodic.