Fifty hyperspectral reflectance images of outdoor scenes

The 50 zipped files hsi_1.zip, ..., hsi_50.zip in this dataset contain averaged hyperspectral reflectance images of outdoors scenes in Matlab MAT format, each of size ~ 336 × 256 × 33. Each hyperspectral reflectance image was obtained by spectrally scaling an original radiance image 1024 × 1344 × 33 by the reflectance of one or more reference surfaces embedded in the scene. The reflectance image was spatially downsampled to ~336 × 256 pixels by averaging over 4×4 pixels and then smoothed spectrally by averaging over adjacent wavelength values 400, 410, ..., 720 nm. <br><br>The file Scenes_and_Names_Key.pdf contains a key for relating image label, e.g. hsi_1, to scene name and image appearance. <br><br>The three zipped illuminant files illum_4000.zip, illum_6500.zip, and illum_25000.zip contain daylight spectra in Matlab MAT format, each of size 33 × 1, drawn from CIE daylight spectral distributions, which can be used to test the effects of illumination changes on scenes.<br><br>The hyperspectral images were acquired by Sérgio Nascimento, Kinjiro Amano, and David Foster from the Minho region of Portugal, 2002-2003.<br><br>For more information about the dataset and its usage, see README_50_Hyperspectral_Reflectance_Images_2022.pdf and the published article https://dx.doi.org/10.1098/rspb.2021.2483.