1. Definition of Fourier transform
Fourier transform is a domain research between the "signal" with time as the independent variable and the "spectrum" function with frequency as the independent variable. The more complicated problems become simpler in the frequency domain, thereby simplifying the analysis process; on the other hand, the physical nature of signals and systems can be better revealed in the frequency domain. When the independent variable "time" or "frequency" is a different combination of continuous form and discrete form, various Fourier transform pairs can be formed, that is, the corresponding relationship between "signal" and "spectrum". Fourier transform includes continuous Fourier transform, discrete Fourier transform, fast Fourier transform and short-time Fourier transform, etc. Two-dimensional discrete Fourier transform is used in digital image processing.
2. Two-dimensional discrete Fourier transform properties
Explain the Fourier transform in a simple way (really easy to understand) - Blog - CSDN Blog
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