【作者】 周广新；

【导师】 赵龙；

【作者基本信息】 国防科学技术大学 ， 计算机科学与技术， 2005， 硕士

【摘要】 人们日常生活离不开各种证件，而证件相片则通常是必不可少的。随着软、硬件条件的不断提高，彩色数字相片逐渐应用于证件制作，我国正推行的第二代居民身份证就采用了真彩色数字相片。同时，数字相片的处理离不开专业图像处理系统如PhotoShop，CoreDraw等。然而数字图像处理系统的操作是一个交互性的、主观性的过程，由于证件相片在规格、色彩标准上的严格要求，以及制证设备色彩还原的不确定性和证照的海量性等特点，使得利用专业图像系统处理证照显得过于专业、繁琐，标准难以把握，效果不佳。本文致力于对数字相片处理智能化的研究，以弥补以上的困难和不足。 本文的主要研究内容和研究成果包括： 1)基于环境采样的图像增强与复原。证照相片既要调整亮度、对比度等以提高图像的可懂度，又要保持颜色的真实性以提高逼真度，本文通过分析Anil K.Jain等人提出的光线补偿方法的不足，提出了一种对环境光及相机参数进行采样，并归化为修正参数对数字相片进行复原与增强的方法，解决了相片处理过程中标准不一、色彩参差不齐的难题，经过系统在上百个相片采集点运行表明效果良好。同时提出了一种理想的环境采样卡设计模型，具有一定的理论意义。 2)基于人像的单连通性提出了一种运用掩模方法提取人像区域并用形态运算进行边缘修整的相片分割方法。适度的对比度增强可以强化相片的立体感，但对比度增大则易出现高光，在证照印刷、压制过程中高光区域往往容易出现“白斑”现象。针对这一问题，本文提出了一种基于Bezier曲线的S形色阶拉伸曲线模型，并实现了算法。经过该算法调整处理的相片色彩层次丰富，立体感强，高光明显减少。 3)实用的智能处理系统离不开实时的相片检测机制，针对特定的相片规格和色彩要求，本文在人脸检测传统方法和先验知识的前提下，提出了一种基于面部椭圆性的脸宽定量测量方法和其它一些具体的相片规格和色彩检测方法，具有一定的创新性。算法经过近十万张相片检测证明具有良好的鲁棒性。 以上研究成果已经全部在《第二代居民身份证图像智能处理系统》中获得应用与验证，并取得良好效果。通过全国数十家同类系统的比较，本系统在可靠性、实用性等方面具有明显优势。课题的研究源之于实践用之于实践，在实际应用中举一反三取得了良好的应用效果，目前《第二代居民身份证图像智能处理系统》已在全国多个地市正式运行，并获得好评。更多还原

【Abstract】 Certificate is very important for one person, and a photo of the person is necessary in certificate usually. With the development of the hardware and software, digital photo of all colors is used in certificates, for instance The Second ID Card of china, in which all colors photo is used. On the other hand, the software of image processing like PhotoShop\CoreDraw became a fashion. The digital photo of certificate can be processed by use these software, but the specialized skill and the ability of control the specification are necessary both to do the job. As these factors above, there are some difficulties in process the photo of certificates.The image enhancement and restitute based of surroundings sampling is one of innovations of the paper. The photo processing of certificate have the particularity, one the one hand, we must adjust brightness and contrast to improve comprehensibility of the photo, one the other hand we must keep the colors like skin to improve the fidelity. The paper analyses the shortage of Lighting Compensation method advanced by Anil KJain, bring a kind of method about color emendation base on Surroundings Sampling Chart and a model of complexion base on YCb’Cr’ color space which changed from YCbCr by nonlinear color transformation. Besides, paper gives a perfect design of Surroundings Sampling Chart.Delete the background of the photo belong the category of image partition. As the portrait is a continuous block, the paper gives a new method by use "mask" chart. Adjust contrast within measure can improve the third dimension of photo, but there are "blaze" when the photo is printed and baked. To solve the question, the paper give a model based of Bezier Curve to extend the hue, and realized the arithmetic.Real time inspect is necessary to improve practicability of intelligent processing system. To improve robust of digital photo inspect, the paper give a filtration method base on density of pixel. Base on complexion model, the paper give an integrated means by demarcating the eyes firstly. The method of face width measure is another innovation of the paper.Integrating with the development of The System of The Second ID Card Photo Intelligent Processing, the paper analyses and designs the whole structure of the system. Dependability and practicability are emphases of the system, and especially some technology involved is discussed deeply.更多还原