How well does sceneFromRGB perform?
Compare a hyperspectral scene estimated from an RGB image to the original hyperspectral scene.
- Read in a multispectral scene and create an sRGB image we should have a script that is s_multispectral2RGB include the gamma rendering
- Read in the RGB image and estimate multispectral image convert to linear given known gamma convert to multispectral image (see s_sceneFromMultispectral.m)
- Compare the estimated multispectral scene to the original multispectral scene comparison of spectral reflectances
The bottom line is that
* the RGB and XYZ are preserved * the illuminant is preserved, but * the reflectances differ a little.
See also: sceneFromFile, sceneAdjustIlluminant, blackbody
Copyright Imageval Consulting, LLC, 2015
Contents
ieInit;
Read in a multispectral scene
fullFileName = fullfile(isetRootPath,'data','images','multispectral','StuffedAnimals_tungsten-hdrs'); wList = 400:10:700; scene = sceneFromFile(fullFileName,'multispectral',[],[],wList); bb = blackbody(sceneGet(scene,'wave'),6500,'energy'); scene = sceneAdjustIlluminant(scene,bb); ieAddObject(scene); sceneWindow; % Display the scene in the scene window
Reading multispectral data with mcCOEF. Saved using svd method
Obtain the sRGB data from the scene
rgb = sceneGet(scene,'rgb'); meanL = sceneGet(scene,'mean luminance'); % Load a display and convert the sRGB to a scene displayCalFile = 'LCD-Apple.mat'; load(displayCalFile,'d'); sceneRGB = sceneFromFile(rgb,'rgb',meanL,d); sceneRGB = sceneSet(sceneRGB,'name','From RGB'); % ieAddObject(sceneRGB); sceneWindow; % Now convert the illuminant wave = sceneGet(sceneRGB,'wave'); bb = blackbody(wave,6500); sceneRGB = sceneAdjustIlluminant(sceneRGB,bb); sceneRGB = sceneAdjustLuminance(sceneRGB,meanL); sceneRGB = sceneSet(sceneRGB,'name','From RGB 6500K'); ieAddObject(sceneRGB); sceneWindow;
