A noise eliminator is provided which can highly compress and store dark current noise components while maintaining characteristics, including many high frequency components. A noise distribution analysis section 10 determines the magnitude distribution of dark current noise components of at least some pixels, and then computes the threshold and typical values for quantization based on this distribution. A quantization section 12 quantizes the dark current noise components based on the computed threshold value, and a memory 14 stores the quantized dark current noise components. An inverse quantization section 16 inversely quantizes the quantized dark current noise components stored in the memory 14 with reference to the typical value computed by the noise distribution analysis section 10. The inversely quantized dark current noise components are supplied to a subtraction section 18, and the subtraction section 18 subtracts the inversely quantized dark current noise components from an image signal.