Another paper about image to sound conversion techniques was written by A. Fusiello et al [7]. Sonification techniques were used to create a system named Multimodal Electronically Travel Aid Device. Their system includes an earphone, a portable computer, a laser pointer which would be used to estimate the z-depth. Finally, a stereo camera pair was used in order to generate stereo vision. The algorithm tracks down the sound signals, applies 3D reconstruction and with the help of sonification techniques sound is generated. Results have shown that laser usage could create problems about the analysis of depth, but the overall results were satisfactory