A tactile codec based on perceptual deadband and differential encoding for tactile Internet

Tactile Internet (TI) introduces tactile feedback to traditional audio-visual feedback for a more immersive user experience in virtual or real environments. Since vibrotactile and force-tactile feedback is the widely experienced tactile feedback in the physical world, efficient transmission of vibrotactile and force-tactile signals is critical for TI. To this end, this work presents a versatile tactile codec based on perceptual deadband and differential encoding, called TC-PDDE, for high-efficiency and low-delay compression of both vibrotactile and force-tactile signals by balancing the reduction of packet size and the decrease of packet rate in tactile communication. First, we adopt a perceptual deadband in the perceptual property to convert original signals into perceptible signals by discarding imperceptible tactile signals. After that, we design a non-uniform quantizer based on the statistical property to quantize and encode the differential compensations of perceptible signals. Finally, we validate the performance of the proposed codec by comparing it with the popular codecs on the standard vibrotactile and self-built force-tactile datasets. The comparison results show that TC-PDDE achieves higher compression efficiency and lower codec delay than other codecs, indicating that TC-PDDE is the superior alternative for real-time tactile applications in TI.