应用于口腔内窥成像系统的波前编码技术研究

发布时间：2018-07-10 13:04

本文选题：口腔窥镜 + 波前编码　；参考：《天津大学》2012年硕士论文

【摘要】：现代口腔窥镜分为照相型和显微型两类。照相型窥镜景深大、视场大,但细节分辨能力较弱;显微型窥镜能很好的分辨细节,但是景深小、视场小。针对需要一定视场和分辨率要求的口腔诊断场合,本文提出了一种波前编码技术口腔窥镜设计方案。在保持原有分辨率不降低的情况下达到拓展口腔窥镜景深的目的,并进行了光学编码成像系统、图像采集系统和编码图像恢复算法的研究,完成的主要工作如下: 根据口腔诊断要求,提出了一种波前编码口腔窥镜设计方案,该方案能够在保证对视场和分辨率要求的情况下,有效拓展景深。该方案在保证一定观测视场的前提下,能有效解决景深和分辨率的矛盾。提出了一种基于规范相关系数的相位板参数优化方法,利用该方法获得了波前编码口腔窥镜光学系统离焦不变性曲线,确定了相位板归一化参数的区间,结合ZEMAX最后确定了三次相位板的结构参数,并且对比分析了传统光学系统和波前编码光学系统的特性,并最终完成了波前编码光学系统的设计和评价。提出了一种嵌入图像采集系统设计方案,实现了图像的采集、存储和显示。改进了现有的波前编码图像退化函数估计方法,提出了一种波前编码退化模型,并实现了波前编码口腔窥镜的退化函数正确估计,采用维纳滤波的算法对辐条型分辨率板、口腔内部病灶等编码图像进行了图像恢复,复原后图像清晰。
[Abstract]:Modern oral endoscopy is divided into two categories: photographic and microscopic. Photographic speculum has large depth of field of view and large field of view, but the resolution of detail is weak, and the microscopic speculum can distinguish details well, but the depth of field is small and the field of view is small. In this paper, a design scheme for oral speculum with wave-front coding technique is proposed for oral diagnosis which requires a certain field of view and resolution. The purpose of expanding the depth of field of oral speculum is achieved without decreasing the original resolution, and the optical coding imaging system, image acquisition system and coding image recovery algorithm are studied. The main work is as follows: according to the requirements of oral diagnosis, a design scheme of wave-front coded oral speculum is proposed, which can effectively expand the depth of field under the condition of ensuring the requirement of field of view and resolution. This scheme can effectively solve the contradiction between depth of field and resolution on the premise of certain observational field of view. In this paper, a phase plate parameter optimization method based on normalized correlation coefficient is proposed. The defocus invariance curve of wave-front coded oral speculum optical system is obtained by using this method, and the range of normalized phase plate parameters is determined. The structural parameters of the cubic phase plate are determined with ZEMAX, and the characteristics of the traditional optical system and the wave-front coded optical system are compared and analyzed. Finally, the design and evaluation of the wave-front coded optical system are completed. A design scheme of embedded image acquisition system is presented, which realizes image acquisition, storage and display. In this paper, the existing methods for estimating the degradation function of wavefront coded image are improved, a degradation model of wavefront coding is proposed, and the degradation function of the wavefront coded oral speculum is estimated correctly. The wiener filter algorithm is used to estimate the resolution plate of the spoke type. The image was recovered from the coding image such as the focus of oral cavity, and the image was clear after restoration.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH776

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