随着成像深度的增加,光衰减会造成光学相干层析技术(OCT)x,tNNtJlgP,成像的局部图像对比度下降,不利于观察组织内部结构特征变化。提出了一种基于自适应多尺度Retinex算法实现对OCT信号衰减的有效补偿。采用大尺度Retinex算法增强图像与其他尺度Retinex算法增强图像之间差值的绝对值均值作为调整参数,实现每个尺度在多尺度Retinex算法中权重的自适应调节。采用人体指尖OCT图像和前臂内侧皮肤OCT图像对算法进行了验证,结果表明:自适应多尺度Retinex算法实现了对OCT原始图像中衰减的有效补偿,同时增强了组织内部细节信息的局部对比度;增强图像的可视化对比度测度(VCM)相对于原始图像平均增加了5740。该算法对于提高组织内部信息可视化具有积极的意义。
With imaging depth increasing, the local contrast in the optical coherence tomography (OCT) image of object decreases, which makes it difficult to observe the internal features of object. An adaptive multi-scale Retinex (AMSR) algorithm is proposed for OCT attenuation compensation. It automatically adjust the weights of Retinex enhanced images with different scales according to the mean values of absolute differences between Retinex enhanced image with large scale and Retinex enhanced images with other small scales. This method is verified by a human fingertip OCT image and skin OCT image that AMSR can effectively compensate the light attenuation in the original OCT image, and enhance the local contrast of structure details within object. Furthermore, comparing with the original OCT image, the visual contrast measure (VCM) of the AMSR enhanced image increases 5740. This method is useful to improve the visualization of structures inside object.