Fast demodulation algorithm for multi-wavelength LED frequency-division modulation transmission hyperspectral imaging

Abstract

Transmission hyperspectral imaging (THI) has the potential for medical applications. The defect of low signal-to-noise ratio (SNR) resulting from strong absorption of biological tissues can be improved by combining frame accumulation with shape function signal modulation and demodulation technology. However, the large amount of imaging data requires processing algorithms that use long computing time. This paper proposed an improved method of fast-one-dimensional phase-locking demodulation algorithm. We modified the fast-one-dimensional phase-locking demodulation algorithm by reducing the phase jitter problem and applied it to every pixel of the two-dimensional image. In order to prove the feasibility of this fast algorithm, the acquisition experiment of phantom images was designed, and the demodulation algorithm was tested. Experimental results show that when processing 2500 frame images with a resolution of 800×600 under the same conditions, the fast demodulation algorithm took 7.1689 s, and the traditional demodulation algorithm (based on Discrete Fourier Transform) used 45.6379 s. The fast algorithm saves 84.29% calculation time while ensuring the image quality. Moreover, this method provides a reference for the development of THI technology.