An image data analysis apparatus adapted to receive color image data having three components for every pixel, detect a color gamut as a range of colors the color image data represents in a predetermined color space, and determine a plurality of apexes defining the color gamut in the color space is disclosed. The image data analysis apparatus includes: a first apex determining unit that detects a minimum grayscale value as a smallest grayscale value among the three components with respect to the pixels included in the color image data, and determines a first apex, which defines the color gamut in the color space, based on the minimum grayscale value; a color image data converting unit that converts the color image data of each of the pixels having the three components into a coordinate point on a predetermined chromaticity plane.