Integral operation formula: ∫ 0dx = c (2) = ln | x |+C. Integration is the inverse operation of differentiation, that is, knowing the derivative function of a function and finding the original function in reverse. In application, the function of integration is not only this, but also widely used in summation, that is, to find the area of curved triangle. This ingenious solution is determined by the special properties of integral.

The definition of differential in mathematics: from the function B=f(A), two groups of numbers A and B are obtained. In A, when dx approaches itself, the limit of the function at dx is called the differential of the function at dx, and the central idea of the differential is infinite division. Differential is the linear main part of function change. One of the basic concepts of calculus.

Related content explanation:

Convolution operation refers to opening an active window with the same size as the template from the upper left corner of the image. The window image and the template pixel are multiplied and added correspondingly, and the brightness value of the window center pixel is replaced by the calculation result. Then, the active window moves one column to the right and performs the same operation. And so on, from left to right, from top to bottom, you can get a new image.

Spatial filtering: based on the spatial relationship between pixels and adjacent pixels, a method to realize image filtering through convolution operation. Frequency domain filtering: Fourier transform the image from image space to frequency domain space, and then analyze the frequency spectrum of the image in frequency domain to change the frequency characteristics of the image.