2. Enter the code in the code editing area. First, read the image with Imread function, and then display the image with Imshow function, so as to compare it with the noise-added image.

3. Various noises can be added by using imnoise function in Matlab, and Gaussian noises can be added by using "Gaussian" parameters.

4. Select the save location and rename the M file, as shown in the figure below. Click "Save" after setting.

5. In this way, Gaussian noise is added to the image in Matlab, and a set of contrast graphs are displayed in the same window, as shown in the following figure.