What is a photometric stereo?
In computer graphics and more specifically, the application of computer vision is a photometric stereo process of creating a three -dimensional (3D) model or representation of a two -dimensional (2D) image based on the way the objects reflect or reflect light in the image. If a photometric stereo algorithm is applied to the object, more than one source image must be available for analysis. For each of the source images used to be used, the object should generally appear in a static position, while the light source moves to reveal different aspects of the surface of the object. Simple methods of photometric stereo -reflecting must know the location of the lights in relation to the object and work best when the object is made of a single material, so the most important and shadows can be predicted. Much more advanced algorithms and techniques do not require so much information in advance and can make several prerequisites or even interpolation of surfaces to complete the parts of the inverted image.
The basic concept of photometric stereo includes taking several images of an object with a light source in each image moving around the object, while the object remains in the same place. By precise measurement of how shadows and highlighting fall to the surface of the building in each figure can calculate the surface normal - the direction that the surface is pointing -. After assembling information about normal measurable objects across a series of 2D images, you can create a 3D model of the object.
Factors such as the depth of shadows and the intensity of the peaks help to determine the changing heights of surface topography. Objects that have a glossy surface are the easiest to measure with photometric stereo, while objects that are made of material with finer shadows such as soft substance can be more difficult. Object, which has a highly reflective surface such as polished chrome, can represent some problems without correct image adjustment as reflections can provide falseResults. Algorithms work best when there is only one light source and no projected shadows, unlike regional light, multiple light sources or light that light through the window or other opening.
There are several uses for photometric stereo technology. When processing computer vision in real time, it can be used to determine the depth of objects in the scene. It can also be used to create accurate 3D object models in photographs for historical, archive or analytical purposes.