There is described an image-processing apparatus for converting a first image data inputted into the image-processing apparatus to a second image data used in a visible-image outputting apparatus, which forms an image so as to make it visible for a human eyesight based on the second image data. The image-processing apparatus includes a data-characteristics acquiring section to acquire data-characteristics of the first image data, including at least one of a dynamic range and a frequency characteristic, by analyzing the first image data inputted into the image-processing apparatus; a memory section to store apparatus-characteristics of the visible-image outputting apparatus; and a processing section to adaptively change a data-converting method for converting the first image data to the second image data, corresponding to the data-characteristics of the first image data acquired by the data-characteristics acquiring section and the apparatus-characteristics of the visible-image outputting apparatus, stored in the memory section.