1. A computer-implemented method for analyzing image noise using an electronic device, the method comprising: receiving an initial image captured by an image capturing device of an image measuring machine using an image capturing card of the electronic device when a lighting device of the image measuring machine is shut down; magnifying an initial gray value of each pixel in the initial image to obtain an updated image; determining whether image noise in the updated image complies with a preset condition by analyzing an updated gray value of each pixel in the updated image, wherein the image noise in the updated image is determined by: determining a first number of pixels whose gray values fall in a first preset sub-range, and calculating a first ratio of the first number of pixels in the updated image; determining a second number of pixels whose gray values fall in a second preset sub-range, and calculating a second ratio of the second number of pixels in the updated image; determining a third number of pixels whose gray values fall in a third preset sub-range, and calculating a third ratio of the third number of pixels in the updated image; determining that the image noise in the updated image complies with the preset condition when the first ratio is greater than or equal to a first preset value, or the second ratio is greater than or equal to a second preset value; determining that the image noise in the updated image does not comply with the preset condition when the third ratio is greater than or equal to a third preset value; and displaying the updated image and analysis results on a display device of the electronic device.