An apparatus for estimating a first angle of a first point on a surface of an object from a multi-/hyperspectral two-dimensional image of the object at respective wavelengths or applying a correction to the multi-/hyperspectral two-dimensional image, the apparatus comprising one or more processors configured to: acquire a multi-/hyperspectral two-dimensional image of an object at respective wavelengths, wherein the multi-/hyperspectral two-dimensional image at the respective wavelengths is formed of a plurality of pixels, each pixel having a set of intensity values corresponding to light intensity values for each of a plurality of wavelengths of light; for at least one pixel of the plurality of pixels corresponding to a first point on a surface of the object, compare the set of intensity values for said at least one pixel to a characteristic curve for the object to determine a measure of similarity of the set of intensity values to the obtained characteristic curve; and estimate a first angle of the first point on the surface of the object corresponding to said at least one pixel from the determined measure of similarity, wherein the first angle is with respect to a plane of the image, or apply a correction to the multi-/hyperspectral two-dimensional image at the first point on the surface of the object using the determined measure of similarity, wherein the characteristic curve characterizes how the object reflects or absorbs light as a function of angle and is indicative of a difference between a spectrum of at least one second point on the surface of the object at a second angle with respect to the plane of the image and a spectrum of at least one third point on the surface of the object at a third angle with respect to the plane of the image, wherein the third angle is a known angle that is different from or substantially different from the second angle. acquire a multi-/hyperspectral two-dimensional image of an object at respective wavelengths, wherein the multi-/hyperspectral two-dimensional image at the respective wavelengths is formed of a plurality of pixels, each pixel having a set of intensity values corresponding to light intensity values for each of a plurality of wavelengths of light; for at least one pixel of the plurality of pixels corresponding to a first point on a surface of the object, compare the set of intensity values for said at least one pixel to a characteristic curve for the object to determine a measure of similarity of the set of intensity values to the obtained characteristic curve; and estimate a first angle of the first point on the surface of the object corresponding to said at least one pixel from the determined measure of similarity, wherein the first angle is with respect to a plane of the image, or apply a correction to the multi-/hyperspectral two-dimensional image at the first point on the surface of the object using the determined measure of similarity, wherein the characteristic curve characterizes how the object reflects or absorbs light as a function of angle and is indicative of a difference between a spectrum of at least one second point on the surface of the object at a second angle with respect to the plane of the image and a spectrum of at least one third point on the surface of the object at a third angle with respect to the plane of the image, wherein the third angle is a known angle that is different from or substantially different from the second angle. <EOS>