Open Access
Review
Table 1
Semantic metrics for different source types
| Source type | Semantic communication metric | Meaning | Refs. |
| Text | Word error rate (WER) | The ratio of the total number of incorrectly recognized words to the total number of words in the ground truth transcript | [84] |
| Bilingual evaluation understudy (BLEU) | The similarity between the machine-translated text and one or more reference translations | [85] | |
| Bidirectional encoder representations from transformers (BERT)-based semantic similarity | The semantic similarity between two pieces of text based on BERT language model | [18] | |
| Semantic similarity metric (SSM) | The semantic similarity between the transmitted sentence and the estimated sentence | [76] | |
| Average bit consumption per sentence | The average number of bits consumed per sentence in the wireless text transmission process | [58] | |
| Speech | Signal-to-distortion ratio (SDR) | The ratio of the signal power to the distortion power | [86] |
| Perceptual evaluation of speech quality (PESQ) | A measure of the perceived quality of speech after being transmitted through a communication channel | [87] | |
| Fréchet deepspeech distance (FDSD) Kernel DeepSpeech Distance (KDSD) |
An evaluation for the quality of synthesized speech signals, indicating the similarity between the reconstructed speech signal and the original signal | [88,89] | |
| Multiple stimuli with hidden reference and anchor (MUSHRA) | The overall quality of the speech source from a human perception perspective | [90] | |
| Image | Peak signal-to-noise ratio (PSNR) | The accuracy of the reconstructed image in terms of pixel accuracy | [91] |
| Structural similarity (SSIM) | The accuracy of the reconstructed image in terms of structural similarity | [92] | |
| Learned perceptual image patch similarity (LPIPS) | The perceptual similarity between two images | [93] | |
| mean intersection over union (mIoU) | The accuracy of a model by comparing the intersection and union of the model’s output results and annotated results | [94] | |
| Image semantic similarity (ISS) | The similarity between two images based on their semantic content | [70] | |
| Video | Motion-based video integrity evaluation (MOVIE) | The distortion in video caused by motion errors | [95] |
| Fusion-based video quality assessment (FVQA) | A comprehensive evaluation combined several quality indicators to judge the overall quality of the video | [96] | |
| Video quality metric (VQM) | The measure for the quality of video based on perceptual image quality factors | [97] | |
| Video quality model for variable frame delay (VQM_VFD) | A variation of VQM that takes into account variable frame delays in the video | [98] | |
| Video multi-method assessment fusion (VMAF) | A metric combines multiple objective quality metrics to predict subjective quality scores | [99] |
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.