A measurement apparatus for measuring a reflection characteristic of an object by deriving a two-dimensional distribution of an optical normal direction based on a plurality of images of the object captured with imaging means, the measurement apparatus comprising: illumination means configured to illuminate the measurement object with a plurality of point light sources illuminating each a measurement point of the object from a different direction and configured to emit light based on illumination images where the luminance of each of the point light sources is modulated according to periodic functions out of phase with one another; imaging means configured to image with a sensor the measurement object illuminated based on the illumination images; characterized in that the measurement apparatus further comprises: phase information calculation means for fitting a change of a measured luminance value over time at each pixel of the sensor to the periodic function based on the plurality of captured images captured by the imaging means and for calculating a phase value at each of the pixels of the sensor based on said fitting, wherein the change at each pixel is identified by at least three measured luminance values; and normal direction calculation means for identifying a point light source located in an illumination direction where a reflection intensity is maximized at a measurement point measured by each of the pixels among the plurality of point sources based on the phase value and identifying thereby a main illumination direction, and calculating the optical normal direction, wherein the optical normal direction is the direction of a half vector between vector indicating the maximum reflection direction, wherein the maximum reflection direction is the direction where the intensity of the specular reflection is maximized, and a vector indicating the main illumination direction and outputting a two-dimensional distribution of the optical normal direction. illumination means configured to illuminate the measurement object with a plurality of point light sources illuminating each a measurement point of the object from a different direction and configured to emit light based on illumination images where the luminance of each of the point light sources is modulated according to periodic functions out of phase with one another; imaging means configured to image with a sensor the measurement object illuminated based on the illumination images; characterized in that the measurement apparatus further comprises: phase information calculation means for fitting a change of a measured luminance value over time at each pixel of the sensor to the periodic function based on the plurality of captured images captured by the imaging means and for calculating a phase value at each of the pixels of the sensor based on said fitting, wherein the change at each pixel is identified by at least three measured luminance values; and normal direction calculation means for identifying a point light source located in an illumination direction where a reflection intensity is maximized at a measurement point measured by each of the pixels among the plurality of point sources based on the phase value and identifying thereby a main illumination direction, and calculating the optical normal direction, wherein the optical normal direction is the direction of a half vector between vector indicating the maximum reflection direction, wherein the maximum reflection direction is the direction where the intensity of the specular reflection is maximized, and a vector indicating the main illumination direction and outputting a two-dimensional distribution of the optical normal direction. phase information calculation means for fitting a change of a measured luminance value over time at each pixel of the sensor to the periodic function based on the plurality of captured images captured by the imaging means and for calculating a phase value at each of the pixels of the sensor based on said fitting, wherein the change at each pixel is identified by at least three measured luminance values; and normal direction calculation means for identifying a point light source located in an illumination direction where a reflection intensity is maximized at a measurement point measured by each of the pixels among the plurality of point sources based on the phase value and identifying thereby a main illumination direction, and calculating the optical normal direction, wherein the optical normal direction is the direction of a half vector between vector indicating the maximum reflection direction, wherein the maximum reflection direction is the direction where the intensity of the specular reflection is maximized, and a vector indicating the main illumination direction and outputting a two-dimensional distribution of the optical normal direction.