Patent ID: 8441687

Claim:
An image processing apparatus comprising: a ΔΣ modulation unit that performs ΔΣ modulation on an image to convert the grayscale of the image, wherein the ΔΣ modulation unit includes: an arithmetic unit that filters a quantization error; an adding unit that adds a pixel value of the image and the output of the arithmetic unit; a quantizing unit that quantizes the output of the adding unit and outputs a quantized value including the quantization error as the result of the ΔΣ modulation; and a subtracting unit that calculates the difference between the output of the adding unit and the quantized value of the output of the adding unit, thereby calculating the quantization error, and a filter coefficient of filtering by the arithmetic unit is determined such that the amplitude characteristics of noise shaping by the ΔΣ modulation unit in a frequency band that is equal to or more than an intermediate frequency band are the inverse characteristics of the spatial frequency characteristics of the human eye, in which at least one of the arithmetic unit, the adding unit, the quantizing unit, and the subtracting unit is configured as a hardware device, and wherein the filter coefficient of filtering by the arithmetic unit is determined such that the amplitude characteristics of noise shaping in the frequency band that is equal to or more than the intermediate frequency band are the inverse characteristics of the spatial frequency characteristics of the human eye, on the basis of the characteristics of equal to or more than a spatial frequency corresponding to the resolution of a display unit that displays the image subjected to the ΔΣ modulation, among the spatial frequency characteristics of the human eye.