Hue preserving is an essential requirement for colour image enhancement.In this paper,we proposed a fast technique in providing hue preserving and enhancement which can be applied to the low-illumination colour image.The technique uses parabola function to enhance the brightness,and then gets the scaling to adjust the RGB value with luminance gain acquired.The hue will keep unchanged while the brightness is increasing.Experimental tests on numerous scene images show that the proposed technique is efficient ...