School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai, China.
Department of Urology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, China.
Int J Med Robot. 2022 Aug;18(4):e2396. doi: 10.1002/rcs.2396. Epub 2022 Mar 29.
In a single-port robotic system where the 3D endoscope possesses two bending segments, only point light sources can be integrated at the tip due to space limitations. However, point light sources usually provide non-uniform illumination, causing the endoscopic images to appear bright in the centre and dark near the corners.
Based on the inverse square law for illuminance, an initial luminance weighting is first proposed to increase the image luminance uniformity. Then, a saturation-based model is proposed to finalise the luminance weighting to avoid overexposure and colour discrepancy, while the single-scale retinex (SSR) scheme is employed for noise control.
Via qualitative and quantitative comparisons, the proposed method performs effectively in enhancing the luminance and uniformity of endoscopic images, in terms of both visual perception and objective assessment.
The proposed method can effectively reduce the image degradation caused by point light sources.
在单端口机器人系统中，由于空间限制，3D 内窥镜具有两个弯曲段，只能在尖端集成点光源。然而，点光源通常提供不均匀的照明，导致内窥镜图像在中心处明亮，在角落处较暗。
基于照度的平方反比定律，首先提出初始亮度加权来提高图像亮度均匀性。然后，提出基于饱和度的模型来最终确定亮度加权，以避免过曝光和颜色差异，同时采用单尺度视网膜（SSR）方案进行噪声控制。
通过定性和定量比较，所提出的方法在增强内窥镜图像的亮度和均匀性方面表现出有效性，无论是在视觉感知还是客观评估方面。
所提出的方法可以有效地减少点光源引起的图像降级。
