Data Compression for Time-Stretch Imaging Based on Differential Detection and Run-Length Encoding

A high-fidelity data compression method based on differential detection and run-length encoding is proposed for a time-stretch imaging system, where a spatial image is mapped to the time domain and then read out by a balanced photodetector for image reconstruction. Differential detection is capable of distinguishing discrepancy of consecutive scans and eliminating identical signals. After the detection, run-length encoding merges consecutive identical data to a single data. In the experiment, a 77.76-MHz line-scan imaging system is demonstrated. The compression ratio of more than 3.8 is achieved. After the data decompression, the image of high fidelity can be reconstructed.