An objective index that substitutes for subjective quality of vibrotactile material-like textures

The presentation of textures is a major application of vibrotactile displays. Lossy data compression is an effective approach for reducing a data size of such textures when delivering them through the Internet. This study developed an objective index that well described material-like textures´ quality changes caused by data compression processes. We introduced a linear combination of the power and amplitude spectra that were weighted by the inverse of a detection threshold curve of vibrotactile stimuli. This combination described the quality deterioration of compressed textures to an accuracy of approximately 80%. These objective indices enhance the development of the lossy data compression algorithms without psychological evaluation tests of subjective quality changes in the textures.