Mirador RTI Viewer Demonstration
April 25, 2014
Reflectance Transformation Imaging (RTI) is a method of capturing how the surface of an object interacts with light. This technique allows for detailed 2D visualization of the intricate surface geometry of an object. At the YDC2 Imaging Lab, the acquisition process takes place under a custom built dome equipped with a camera at the top and 45 lights located on tiers at different heights. Information about surface reflectance is captured per pixel as a stationary camera takes a series of images of an object under varying lighting conditions. One image is taken per illumination by one of 45 lights positioned around a dome. Different highlights and shadows are present in each image taken. Based upon these reflectance values, RTI software creates surface normals for each pixel to predict how light will reflect off of the surface of the object. In the end, these 45 images are processed into a single visualization file that allows for interactive relighting and rendering for enhancement of the minute details of the surface geometry.
YDC2 has created a demonstration of RTI viewing capability within the Mirador multi-up image comparison tool. The WebRTIViewer, developed by the Visual Computing Laboratory at Istituto di Scienza e Tecnologie dell'Informazione (ISTI), was integrated into the Mirador tool. This RTI viewer integration is for demonstration purposes only. The functionality is not available yet in the released version of Mirador, and many features are in development for RTI viewing.
If your browser is not configured to view RTI, follow the instructions displayed within the Mirador viewer. Once configured, to zoom in and out on the RTI image, use the plus and minus buttons at the top left of the window. Click the light bulb to toggle between using the mouse to pan the image and moving the light source: Click the recycle icon at the top right corner of the page to reset the viewer: