hdrscope: per-pixel lighting analysis tool


We would like to announce the release of a new tool for image- based light analysis. Hdrscope is a Windows based, user friendly tool that can process and analyze High Dynamic Range (HDR) photographs and rendered images from Radiance Lighting Simulation and Visualization software. The analysis techniques focus on per-pixel luminance analyses. It is free and can be downloaded from: http://courses.washington.edu/hdrscope/

Hdrscope features a combination of existing and novel tools and image processing techniques. The fundamental algorithms and programs running behind the scenes within hdrscope are derived from Radiance software, and new features are added. One of the most exciting capabilities is the ability to isolate and analyze a region or two regions of interest from an image; the regions can be defined using a rectangle, circle or a closed polygon interactively. Luminance values, ratios, descriptive statistical calculations, percentile ratios, criterion rating, and luminance contrast are reported. The software also provides a front end to Evalglare. It allows for calibration using luminance measurements, or illuminance measurements taken at the camera level for fisheye images. It provides an automated image capture tool for selected Canon cameras to take multiple exposure photographs. ‘Single aperture / multiple shutter speed’ option is used for general image capture; and ‘two apertures / multiple shutter speed’ option is provided to capture the sun and the sky. Photosphere (of course) is recommended for image assembly.

The work behind the software formed the basis of my student’s (Viswanathan Kumaragurubaran) Master of Science thesis in Architecture at the University of Washington (Seattle). If you have any questions, feedback, or comments, please let us know ([email protected])


Mehlika Inanici