Kuvapolarimetri

Kuvapolarimetri, also known as imaging polarimetry, is an optical technique that measures the polarization state of light across an image. Unlike conventional cameras that record only intensity information, a kuvapolarimetric system captures both the spatial distribution of light and its polarization properties. This allows for the retrieval of additional information about the scene being imaged, which can be invisible to the naked eye or standard imaging devices.

The polarization of light describes the orientation of its electric field oscillations. Different materials and surface interactions can alter the polarization of light, for example, through reflection, scattering, or transmission. Kuvapolarimetri exploits these changes. By analyzing how the polarization state of light varies across an image, one can infer properties such as surface texture, material composition, the presence of transparent or semi-transparent objects, and the shape and orientation of objects, particularly in challenging lighting conditions or when dealing with low contrast.

The process typically involves using a polarimetric filter or a liquid crystal variable retarder in conjunction with a camera. By acquiring multiple images with different polarization sensitivities, the full polarization state of the light at each pixel can be reconstructed. This reconstructed data can then be processed to generate various polarimetric images, such as degree of linear polarization (DoLP), angle of polarization (AoP), and degree of circular polarization (DoCP). These derived images highlight features that are otherwise obscured.

Applications of kuvapolarimetri are diverse and include remote sensing, where it can help distinguish between different types of vegetation or identify man-made objects camouflaged in natural environments. In machine vision, it enhances object detection and recognition, particularly for transparent or reflective surfaces. It also finds use in medical imaging for characterizing biological tissues and in scientific research for studying the properties of materials and astronomical objects.