SPSIM - What does SPSIM stand for? The Free Dictionary
References in periodicals archive
Some recently proposed approaches incorporating the similarity assessment for IQA purposes are the Haar wavelet-based perceptual similarity index (HaarPSI)  and SuperPixel-based similarity index (SPSIM) .
Zhou, "SPSIM: a SuperPixel-based SIMilarity index for full-reference image quality assessment", IEEE Trans.