数字图像处理课件-lecture02 dip fundamentals

Chapter II.Digital Image Fundamentals,Dong NingSchool of Instrument Science and Opto-Electronics EngineeringHefei University of TechnologyEmail: Tel:Outline,Review of Last CourseElements of Visual PerceptionImage Sensing and AcquisitionImage Sampling and QuantizationBasic Relationships Between Pixels,Review of Last Course,数字图像处理的起源数字图像处理的应用数字图像处理的课程内容,3,一幅图像胜过千言万语!,4,5,图像中的信息,星星星星的等级星星的统计星座（坐标间的关系）,6,图像的信息提取,7,数字图像处理的出现,8,数字图像处理的起源,20世纪60年代NASA（美国国家宇航局）处理飞船从月球发回的照片1964年，JPL实验室（喷气推进实验室）徘徊者7号灰度变换、去噪声、几何校正、傅里叶变换、二维线性滤波1965年徘徊者8号解卷积、消除运动模糊,9,-历史上著名的造假照片,10,图像处理的应用,11,历史上第一幅造假照片出现在 1860 年。这幅林肯的照片实际上是在参议员约翰卡尔霍恩的身体上安了林肯的头。请注意，历史上第一幅永久映像出现在 1826 年，而 伊斯曼干版公司（柯达前身）直到 1881 年才成立,12,1930年，一个失宠的人民委员被从与斯大林的合影中抹掉了。,13,1997年，58名旅游者在埃及一所寺庙中被杀，瑞士一家报纸将一摊水迹篡改成红色的血流。,14,Applications,From beast to beautyPS (Photoshop),?,15,Applications,Face growth prediction for lost children searching,Radiation from EM spectrum,1. EM waves = a stream of massless (proton) particles, each traveling in a wavelike pattern and moving at the speed of light.2. Spectral bands are grouped by energy per photon Gamma rays, X-rays, Ultraviolet, Visible, Infrared, Microwaves, Radio waves,物理图像,17,资源1号，天津市,资源2号，智利,物理图像,18,Gamma-Ray Imaging,X-ray Imaging,To monitoring environmental conditions on the planet,Visible blue,Visible green,Visible red,Near infrared Middle infrared Thermal infrared Middle infrared,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,DIP Application Videos,37,Artificial Image中国商飞C919大型客机奇幻视觉之旅,38,39,40,41,42,43,44,45,46,DIP- An Interdiscipline（交叉学科）,47,数学,光学,信息科学,工程技术,摄影与美术,计算机技术,DIP,DIP- An Interdiscipline（交叉学科）,48,军事,地球科学,农业,现代工业,航空航天,医学,DIP,军事,地球科学,农业,现代工业,航空航天,医学,DIP structure,Image Acquisition,Image Enhancement,52,Image Restoration,Denoising Geometric correctionRadiometric correction,53,Image Compression,54,Image Segmentation,Morphological processing,56,Image representation and description,Usually follow the output of a segmentation stageConvert the data for a form suitable for subsequent computer processing,A example on Car License Plate Recognition,57,数字图像的基础知识,Digital Image Fundamentals,58,视觉Construct of an eye,3 membranes enclose the eye cornea (角膜) & sclera (巩膜) choroid (脉络膜) retina (视网膜)Pattern vision: discrete light receptors over the surface of retina cones 锥状细胞 rods 柱状细胞,Image Formation in the Eye,Distribution of Rods & Cones,锥状细胞 Cones800万R/G/B柱状细胞 Rodes1.2亿低照度信息,62,9:29:27,Color Sensing / Color Perception,These are approximations of the responses to the visible spectrum of the “red”, “green”, and “blue” receptors of a typical human eye.,9:29:27,luminance,hue,saturation,photo receptors,brain,The eye has 3 types of photoreceptors: sensitive to red, green, or blue light.,The brain transforms RGB into separate brightness and color channels (e.g., LHS).,Color Sensing / Color Perception,Brightness Adaptation and Discrimination,brightness discrimination is poor (the Weber ratio is large) at low levels of illumination,Perceived Brightness,Simultaneous Contrast,Optical Illusion (I),Optical Illusion (II),70,Optical illusion III,视觉的一些特点,高级的生物光学系统分辨率超高光谱响应范围（可见光区的由来）动态范围（明视觉、暗视觉）视觉的错觉,71,人造成像,72,CCD的发明,73,CCD的基本原理,P型 MOS光敏元,电荷的移动,三相CCD时钟电压与电荷转移的关系(a) 三相时钟脉冲波形； (b) 电荷转移过程,线阵CCD传感器,面阵CCD传感器,9:29:27,Image Sensors,CCD structure,79,CCD timing example: 4-Phase Vertical Transfer,VTP1,VTP2,VTP3,VTP4,VTP1,VTP2,VTP3,VTP4,VTP1,t1,t2,t3,t4,t1,VTP1,VTP2,VTP3,VTP4,Direction of Transfer,pixel n,pixel n+1,pixel n+2,4 electrodes per pixelAlternate bias voltages on electrodes to form potential wells & barriers to move charge along shift registerAll of the Vertical signal voltages range is from -7.5V (L) to +15V (H) thats reason why you need a external vertical driver to shift the 3.3/5V logic pulses into such big swing,ADI ITS presentation,81,Horizontal Shift Register Timing,H2,H1,H2,H1,H2,H1,H2,H1,H2,H1,RG,CCDOUT,H3,H1,RG,reset level,data level,CCDOUT,Charge is converted to voltage at CCD output,ADI ITS presentation,82,Electronic Shutter,LateralOverflow Drain,OD bias,SUBCK,SUBCK will remove the potential barrier between the pixel and the overflow drain to clear each pixel at the start of exposurePrevents blooming (charge overflow into the adjacent pixel),Photodiode,Incident Light,Color Filter,ADI ITS presentation,83,Precision Shutter mode (Electronics Shutter),HD,2nd SUBCKEach HD line has one SUBCK. But if the SUBCK is to far to the SG the 2nd SUBCK can be used to reduce the exposure time,SUBCK,Exposure time,VSGx,填充因子（ Fill Factor ）-实际感光面积占像素面积的比值,井深（Well Capacity）-像素可堆积电荷的多少,多数CCD可堆积85K个电荷高品质的CCD可堆积350K个电荷影响灵敏度的一个因数衡量动力学范围的一个因素,放大后的CMOS芯片,86,背照式传感器,87,CCD vs. CMOS,88,Artificial Image Sensors,90,TDI技术,91,92,93,94,数字图像,95,模拟与数字连续与离散抽样与量化,Sampling（抽样）,Quantization（量化）,Bits to represent the value of the function,Image Sensing, Sampling and Quantization,9:29:27,Image Sampling,9:29:27,Results of image sampling and quantiation,数字图像,二维矩阵f(x,y)图像在计算机中的表示和存储原始图像被等间隔的网格分割成大小相同的小方格（grid），其中的每一个方格我们称之为像素点，简称像素或者像元（pixel）。,101,像素,像素是构成数字图像的最小基本单位，其基本属性包括像元位置和灰度值。像元位置即像素所在的行和列的坐标，（x，y）灰度值即像素对应的光学亮度值,102,图像的数字化过程就是构建像素矩阵的过程,Sample of Luna,103,Digital Image Representation,A digital image can be considered a matrix whose row and column indices identify a point in the image and the corresponding matrix element value identifies the gray level at that point.,9:29:27,Representing Digital Images,数字图像的基本属性,坐标关系 （左上角为原点）空间分辨率（Spatial Resolution）灰度分辨率（Gray Level Resolution）动态范围（Dynamic Range）,106,Spatial Resolution,Subsample & Resample,Gray-level Resolution,16,8,4,2,影响分辨率的几个因素,CCD像素个数（空间）灵敏度/动态范围（强度）镜头MTF（衍射/像差）,110,像素的连通性 邻域(Neighbor),111,Nonunif