Real-Time Adaptive Radiometric Compensation

• Published in: IEEE transactions on visualization and computer graphics Vol. 14; no. 1; pp. 97 - 108
• Main Authors: Grundhofer, A., Bimber, O.
• Format: Journal Article
• Language: English
• Published: United States IEEE 01.01.2008; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Algorithms; Animation; Brightness; Color; Colorimetry - methods; Compensation; Computer Graphics; Computer Systems; computer vision; display algorithms; Dynamic range; enhancement; Heuristic algorithms; Image analysis; Image contrast; Image Enhancement - methods; Image generation; Image Interpretation, Computer-Assisted - methods; image processing; Imaging, Three-Dimensional - methods; Information Storage and Retrieval - methods; Lighting - methods; Luminance; Numerical Analysis, Computer-Assisted; picture/image generation; Projection; Radiometry; Real time; reflectance; Reflectivity; Surface texture; image processing; color; display algorithms; reflectance; Computer graphics; computer vision; radiometry; picture/image generation; enhancement
• ISSN: 1077-2626; 1941-0506
• DOI: 10.1109/TVCG.2007.1052

Recent radiometric compensation techniques make it possible to project images onto colored and textured surfaces. This is realized with projector-camera systems by scanning the projection surface on a per-pixel basis. Using the captured information, a compensation image is calculated that neutralizes geometric distortions and color blending caused by the underlying surface. As a result, the brightness and the contrast of the input image is reduced compared to a conventional projection onto a white canvas. If the input image is not manipulated in its intensities, the compensation image can contain values that are outside the dynamic range of the projector. These will lead to clipping errors and to visible artifacts on the surface. In this article, we present an innovative algorithm that dynamically adjusts the content of the input images before radiometric compensation is carried out. This reduces the perceived visual artifacts while simultaneously preserving a maximum of luminance and contrast. The algorithm is implemented entirely on the GPU and is the first of its kind to run in real time.