1. An image discernment apparatus, comprising: a count unit to count the number of pixels, of which the gradation levels are smaller than a predefined first threshold value, from among pixels positioned in the periphery of the image; a discernment unit to discern an image to be of an appropriate gradation, even if the image is in a dark tone, if the number of pixels, as a result of the counting, is not less than a second threshold value; and a ratio calculation unit to calculate the ratio of the number of pixels calculated by said count unit to the total number of pixels positioned in the surroundings of said image, wherein said discernment unit discerns an image to be of an appropriate gradation even if the image is in a dark tone if the ratio is not less than a predefined third threshold value.