An apparatus, method and medium outputting a wide gamut space image in which one or more parameters that are needed to convert an existing color space into a wide gamut space are experimentally determined and then are applied to an image. The apparatus includes a feature extraction module to extract one or more feature differences between a standard gamut and a wide gamut of an image, a color range setting module to set a hue range according to the extracted feature differences and one or more experimentally determined parameters, and a conversion module to convert the image according to the extracted feature differences, the experimentally determined parameters, and the hue range.