Wireless Transmission of Images with the Assistance of Multi-level Semantic Information

Semantic-oriented communication has been considered a promising method to boost bandwidth efficiency by only transmitting the semantics of the data. In this paper, we propose a multi-level semantic aware communication system for wireless image transmission, named MLSC-image, which is based on deep learning (DL) techniques and trained in an end-to-end manner. In particular, the proposed model includes a multilevel semantic feature extractor, that extracts both the high-level semantic information, such as the text semantics and the segmentation semantics, and the low-level semantic information, such as local spatial details of the images. We employ a pret-rained image caption to capture the text semantics and a pre-trained image segmentation model to obtain the segmentation semantics. These high-level and low-level semantic features are then combined and encoded by a joint semantic and channel encoder into symbols to transmit over the physical channel. The numerical results validate the effectiveness and efficiency of the proposed semantic communication system, especially under the limited bandwidth condition, which indicates the advantages of the high-level semantics in the compression of images.