An image processing method, applied to a device including a sensor and a processor connected to the sensor, the sensor including a plurality of pixels, in which each of the pixels senses three primary colors and an infrared ray of an image, the processor executing the method including: calculating a real response value of the infrared ray without a crosstalk interference from the three primary colors according to the crosstalk interference from the three primary colors to the infrared ray; calculating real response values of the three primary colors without a crosstalk interference from the infrared ray according to the crosstalk interference of the real response value from the infrared ray to the three primary colors; and increasing a brightness of the image according to a brightness of the real response value of the infrared ray and the real response values of the three primary colors.