Bayesian dense inverse searching algorithm for real-time stereo matching in minimally invasive surgery
This is an incremental improvement for surgical imaging, addressing textureless surfaces and photometric inconsistencies in real-time depth estimation.
The paper tackled real-time stereo matching for minimally invasive surgery by proposing a Bayesian dense inverse searching algorithm, achieving 10 Hz on 640*480 images with higher accuracy and fewer outliers than baseline methods.
This paper reports a CPU-level real-time stereo matching method for surgical images (10 Hz on 640 * 480 image with a single core of i5-9400). The proposed method is built on the fast ''dense inverse searching'' algorithm, which estimates the disparity of the stereo images. The overlapping image patches (arbitrary squared image segment) from the images at different scales are aligned based on the photometric consistency presumption. We propose a Bayesian framework to evaluate the probability of the optimized patch disparity at different scales. Moreover, we introduce a spatial Gaussian mixed probability distribution to address the pixel-wise probability within the patch. In-vivo and synthetic experiments show that our method can handle ambiguities resulted from the textureless surfaces and the photometric inconsistency caused by the Lambertian reflectance. Our Bayesian method correctly balances the probability of the patch for stereo images at different scales. Experiments indicate that the estimated depth has higher accuracy and fewer outliers than the baseline methods in the surgical scenario.