A visual processing device comprising: a parameter output unit operable to output a luminance adjustment parameter based on a parameter expressing the ambient light; a spatial processing unit operable to perform a predetermined spatial processing to an image signal of a target pixel that has been inputted, by using the image signal of pixels surrounding the target pixel, and to output, as a processed signal of the target pixel, an average value of the image signal of surrounding pixels as a result of the spatial processing; a conversion characteristic registration unit operable to register a plurality of conversion characteristics, each of which is a two-dimensional lookup table which gives a value of an output signal of the target pixel with respect to the image signal of the target pixel and the signal obtained by spatially processing the image signal; a controller operable to specify the conversion characteristics to be read out with the luminance adjustment parameter and specify a value of a degree of synthesis of the respective conversion characteristics; a conversion characteristic creation unit operable to obtain the specified conversion characteristics from the conversion characteristic registration unit and produce a created conversion characteristic with the value of the degree of synthesis; and a visual processing unit operable to convert the image signal of the target pixel that has been inputted in accordance with the average value of surrounding pixels and the created conversion characteristic, and to output the output signal of the target pixel, wherein the conversion characteristic is that the brightness and/or the local contrast of the image signal is adjusted based on the luminance adjustment parameter, and for any given value of the image signal of the target pixel, the value of the output signal of the target pixel monotonically decreases with respect to the average value of pixels surrounding the target pixel. a parameter output unit operable to output a luminance adjustment parameter based on a parameter expressing the ambient light; a spatial processing unit operable to perform a predetermined spatial processing to an image signal of a target pixel that has been inputted, by using the image signal of pixels surrounding the target pixel, and to output, as a processed signal of the target pixel, an average value of the image signal of surrounding pixels as a result of the spatial processing; a conversion characteristic registration unit operable to register a plurality of conversion characteristics, each of which is a two-dimensional lookup table which gives a value of an output signal of the target pixel with respect to the image signal of the target pixel and the signal obtained by spatially processing the image signal; a controller operable to specify the conversion characteristics to be read out with the luminance adjustment parameter and specify a value of a degree of synthesis of the respective conversion characteristics; a conversion characteristic creation unit operable to obtain the specified conversion characteristics from the conversion characteristic registration unit and produce a created conversion characteristic with the value of the degree of synthesis; and a visual processing unit operable to convert the image signal of the target pixel that has been inputted in accordance with the average value of surrounding pixels and the created conversion characteristic, and to output the output signal of the target pixel, wherein the conversion characteristic is that the brightness and/or the local contrast of the image signal is adjusted based on the luminance adjustment parameter, and for any given value of the image signal of the target pixel, the value of the output signal of the target pixel monotonically decreases with respect to the average value of pixels surrounding the target pixel. wherein the conversion characteristic is that the brightness and/or the local contrast of the image signal is adjusted based on the luminance adjustment parameter, and for any given value of the image signal of the target pixel, the value of the output signal of the target pixel monotonically decreases with respect to the average value of pixels surrounding the target pixel.