In this paper, the signal-to-noise ratios (SNR) of two image channels were enhanced with the fast digital lock-in algorithm. In order to simultaneously improve the quality of white and fluorescence images obtained by fluorescence endoscope, and improve the SNR to achieve a better image processing effect, two sources of white light and near-infrared light of a fluorescence endoscope were modulated, then the acquired images were demodulated into white and fluorescence images. A fluorescent endoscope experimental platform was setup to acquire endoscopic images of a target dyed by indocyanine green. The experimental results showed that the SNR of white and fluorescent images without the lock-in algorithm were 36.56 dB and 33.47 dB, respectively. However, with the lock-in algorithm, the SNR of white and fluorescent images were 39.54 dB and 35.70 dB, respectively. The SNR of white and fluorescent images was increased by 8.2% and 6.7%, respectively, by appling the digital lock-in algorithm. Therefore, this novel fluorescence endoscope based on the fast digital lock-in algorithm can rapidly and simultaneously obtain two-channel images of white light and fluorescence, effectively enhance the SNR of white and fluorescent images, and improve the imaging quality.

本文采用快速数字锁定算法增强了两个图像通道的信噪比（SNR）。为了同时提高荧光内窥镜获得的白色和荧光图像的质量，并提高信噪比以获得更好的图像处理效果，调制了荧光内窥镜的白光和近红外两种光源，然后采集图像被解调为白色和荧光图像。设置了荧光内窥镜实验平台，以获取由吲哚菁绿染色的目标的内窥镜图像。实验结果表明，没有锁定算法的白色和荧光图像的SNR分别为36.56 dB和33.47 dB。但是，使用锁定算法，白色和荧光图像的SNR分别为39.54 dB和35.70 dB，分别。通过应用数字锁定算法，白色和荧光图像的SNR分别提高了8.2％和6.7％。因此，这种基于快速数字锁定算法的新型荧光内窥镜可以快速，同时获得白光和荧光的两通道图像，有效提高白光和荧光图像的信噪比，提高成像质量。