An image display device controls a backlight luminance on the basis of a plurality of areas corresponding to LEDs, which are defined by dividing an input image. One measurement method includes transmitting the near-infrared radiation towards the opaque material and determining relative absorbance levels over a range of near-infrared wavelengths. To avoid this green house gas problem and yet produce liquid fuels, an electro-thermal energy storage system that may be wind-powered is described. The allocation of the memory space allocated to at least one of the determined inactive tasks is modified. The LED current is further adjusted in response to the reflected signal. For example, a phosphorescent material can be used to provide an object with high contrast as compared to a background that the object is imaged against.