A method of calibrating an image sensor may include detecting a response from a pixel of the image sensor as a result of light having an intensity impinging on the pixel, and measuring the actual standard deviation of the response of the pixel at the intensity of light. The method may also include determining an averaging number for the pixel at the intensity. The averaging number may be a number of responses of the pixel at the intensity to be averaged to attain an average response having a standard deviation less than or equal to a target value. The method may further include determining the average response of the pixel using the determined averaging number.