The CREATE project included interdisciplinary research on appearance and scene rendering. The technological advances in digital imaging allow renditions of real scenes that were not possible in conventional silver-halide photography.  This project studied the goals and performance of image making techniques. The project included psychophysics, fine-art painting, digital photography and image processing.  The project studied the rendition of the same objects in different illuminations.  The psychophysics measured the appearance of the objects; the painting measured how an artist would render the scenes; the photography showed how cameras capture scenes; and the image processing compressed the High-Dynamic Range (HDR) scene into a Low-Dynamic-Range (LDR) picture.  In artificial test targets using flat displays, the appearance of colored surfaces remains nearly constant with uniform changes in illumination.  As well, the range of light reflected by artists’ paints and conventional photographic prints fits the range of the scene.  All this changes with 3-D objects, non-uniform illumination, shadows, and different spectral illuminants.  These illumination induces HDR scenes far exceed the range of the reproduction media.  This project studied the mechanisms used by humans to sense real-life scenes, and the best image processing techniques to render them in reproductions.  These processing techniques require spatial comparisons similar to those found in human vision.

Complete Report on Measuring Appearance

“Reflectance, Illumination and Appearance”

RIA.pdf

Color Imaging Conference (CIC 2010)

”Analysis of Spatial Image Rendering”

CIC 2010

Proceedings from Scientific Meetings

3-D Mondrian Papers

Photographs of LDR and HDR Mondrians

LDR and HDR Albums

XYZ Measurements of the Paints, the LDR/HDR Mondrian Scenes, and the LDR/HDR Watercolor Paintings

Paints

XYZvalues.pdf

Magnitude Estimates of Changes in Appearance

This table shows the average of eleven observers’ results of the selected areas in the pair of 3-D Mondrians. We converted the observer magnitude estimates to an observed Munsell chip designation, and then to MLAB Color space.  The observer data shows that in general the color estimates in LDR are closer to ground truth than HDR.  Nevertheless, there are areas in the HDR scene that look like the ground truth standard colors. The change in appearance of individual areas depends on the illumination and the other areas in the scene. The sources of

illumination, the distribution of illumination, and inter-reflections of light from one facet to another, all play a part generating appearance. One cannot generalize the influence of the surface property (reflectance) of the facet on appearance. Illumination and all of its spatial properties show significant influence on the hue, lightness and chroma of observed appearances.

MagEstApp.pdf

A Painters Measurements of Appearance

Carinna Parraman painted with watercolors a record of the appearance of the LDR/HDR Mondrian.  We can measure the reflectance spectra of the original paint, and the reflectance spectra of how the scenes appeared to the artist.  This allows direct comparisons of the objects’ reflectance with appearance.

Watercolor