【作者】 雷韬；

【导师】 蔡怀宇；

【作者基本信息】 天津大学 ， 光学工程， 2012， 硕士

【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。更多还原

【Abstract】 The modern dental endoscope has two different types, photographic type and microscopic type. Compared with microscopic dental endoscope, the photographic dental endoscope performs better in the depth of field and the field of view. However, the most significant defect of photographic dental endoscope is the poor ability of resolution. Meanwhile, the microscopic dental endoscope has better ability of resolution. In order to solve the contradiction between the depth of field and the resolution in endoscopic imaging system, a new integrated optical imaging technology which is called as wavefront coding , is introduced in this dissertation. The main contents of this dissertation are as follows:According to ral diagnostic requirements, a wavefront coding dental endoscope design is proposed, which can extend the depth of field and guarantee the field of view and resolution. Meanwhile ,the design can effectively solve contradiction between the depth of field and the resolution.A phase mask optimized method based on the standardized correlation coefficient is introduced and the wavefront coding dental endoscope’s defocus invariance curve is accomplished. The range of phase plate normalized parameter is obtained. The specific phase mask normalized parameter is obtained by ZEMAX. Meanwhile the design and the evaluation of wavefront coding dental endoscope is accomplished.A im age acquisition s ystem design is prop osed, which accom plish the im age acquisition, transmission and display.The wavefront coding image degradation function estimation module is improved. The resolution board and oral lesion coded image is restored by wiener filtering algorithm based the degradation.更多还原