数字图像处理课件(冈萨雷斯)N02.ppt

1、 Digital Image Processing（信息学院（信息学院 陈辉）陈辉）Digital Image ProcessingProf. Dr.Chen Hui School of ISE, Shandong University email: Lecture 2 Digital Image Processing（信息学院（信息学院 陈辉）陈辉）Introduction Background Digital Image Representation Fundamental Steps In Image Processing System Elements of Digital Image

2、 Processing System Further Readings One Picture is worth more than a thousand words.Chapter 1 no. 1YOXr,c()I Digital Image Processing（信息学院（信息学院 陈辉）陈辉）BackgroundApplications: Improvement of pictorial information for human interpretation. Processing of scene data for storage, transmission, and represe

3、ntation for autonomous machine perception. Scope definition Origins State of the art Principals Overview of systemChapter 1 no.2 Digital Image Processing（信息学院（信息学院 陈辉）陈辉）What are DIP and scope? (read book)nDigital Image: discrete both in space (x,y) and amplitude fnProcessing by digital computernPic

4、ture elements, image element, pels, pixels nNot limited to visual band: wide & variety field of applicationsnNo general agreement on the scope of processing, analysis, vision. Input & output, emulate human vision (AI). No clear-cut boundaries.n I/O images, extract attributes, recognizing objects. Su

5、ch as analysis of text.Chapter 1 no. 3 Digital Image Processing（信息学院（信息学院 陈辉）陈辉）History Early 1920s, Bartlane cable picture transmission system. (special character, 515 gray level). Middle 1960s, space shuttle, aerial and satellite imagery.(large-scale computer& space programDIP concepts). Others, m

6、edical image(x-ray, MRI,CT.), geography, archeology, astronomy, physics (high-energy plasmas, electron microscope). Machine perception: character recognition, industrial machine vision, military recognizance, matching fingerprints, etc.Chapter 1 no. 4 Digital Image Processing（信息学院（信息学院 陈辉）陈辉）History

7、 (cont.1)Chapter 1 no. 5Digital images Digital Image Processing（信息学院（信息学院 陈辉）陈辉）History (cont.2)Chapter 1 no. 6Digital images Digital Image Processing（信息学院（信息学院 陈辉）陈辉）History (cont.3)Chapter 1 no. 7Digital image processed by computer Digital Image Processing（信息学院（信息学院 陈辉）陈辉）ExamplesChapter 1 no.8Gam

8、ma ray Digital Image Processing（信息学院（信息学院 陈辉）陈辉）Examples (cont.1)Chapter 1 no. 8X ray Digital Image Processing（信息学院（信息学院 陈辉）陈辉）Example (cont.2)Chapter 1 no. 9Visible & Infrared Digital Image Processing（信息学院（信息学院 陈辉）陈辉）Example (cont.4)Chapter 1 no. 10Infrared Digital Image Processing（信息学院（信息学院 陈辉）陈辉）

9、Examples (cont.5)Chapter 1 no. 11Radio band Digital Image Processing（信息学院（信息学院 陈辉）陈辉）Examples (cont.6)Chapter 1 no. 12Ultrasound Digital Image Processing（信息学院（信息学院 陈辉）陈辉）Examples (cont.7)Chapter 1 no. 13Visual spectrum Digital Image Processing（信息学院（信息学院 陈辉）陈辉）Digital Image RepresentationDefinition:

10、monochrome image ( image) , a two-dimensional light intensity function f(x,y), point (x ,y) spatial coordinates, f brightness value of the point.Digital Image:Discretized both in spatial coordinates and brightness(matrix, elements, pixels).Image size and the number of gray level are advantages to be

11、 chosen as integer power of 2. (512*512, 128!) YOXr,c()IOXYf ()x,yChapter 1 no. 14 Digital Image Processing（信息学院（信息学院 陈辉）陈辉）Digital Image Representation (cont.)Chapter 1 no. 15 Digital Image Processing（信息学院（信息学院 陈辉）陈辉）Digital Image Representation (cont.)Chapter 1 no. 15 Digital Image Processing（信息学院

12、（信息学院 陈辉）陈辉）Fundamental Steps In Image Processing SystemImage acquisition ( image sensor & AD converter) camera, scanner.Preprocessing (improve image) enhancing contrast, removing noiseSegmentation partition an input image into its constituent part, output raw pixel data either of boundary or region

13、. Representation and description (descriptors,feature selection)Recognition and interpretation assign a label to an object, assign meaning to recognized objects. an example: automatic reading of the address on piece of mail.Chapter 1 no. 16 Digital Image Processing（信息学院（信息学院 陈辉）陈辉）Elements of Digita

14、l Image Processing SystemChapter 1 no. 17 Digital Image Processing（信息学院（信息学院 陈辉）陈辉）Further ReadingSlides available as pdf filesR. C. Gonzalez, R. E. Woods, “Digital Image Processing”, 2nd edition,Prentice-Hall, 2002,Pratt, W. K., Digital Image Processing, 3rd ed. , John Wiley & Sons, NY., 2001.IEEE

15、Transactions on Image Processing. IEEE Transactions on Pattern Analysis and Machine Intelligence.Computer Vision and Image Understanding.IEEE Transactions on Signal Processing.IEEE Transactions on Medical Imaging.Chapter 1 no. 18 Digital Image Processing（信息学院（信息学院 陈辉）陈辉）Elements of Visual Perception

16、Structure of Human EyeChapter 2 Elements of visual perception no. 1 Digital Image Processing（信息学院（信息学院 陈辉）陈辉）Image Formation in the Eye 2.55mmElements of visual perception no. 2 Digital Image Processing（信息学院（信息学院 陈辉）陈辉）Brightness Adaptation Cannot operate such a range simultaneously. Rather, by chan

17、ges in its overall sensitivity.Elements of visual perception no. 3 Digital Image Processing（信息学院（信息学院 陈辉）陈辉）Brightness Discrimination ExperimentBrightness discrimination is poor at low levels of illumination.Elements of visual perception no. 4 Digital Image Processing（信息学院（信息学院 陈辉）陈辉）Mach Band Patte

18、rnVisual system tends to undershoot or overshoot around the boundary of regions of different intensities.Elements of visual perception no. 5 Digital Image Processing（信息学院（信息学院 陈辉）陈辉）Simultaneous Contrast A regions perceived brightness does not depend simply on its intensity. Elements of visual perce

19、ption no. 6 Digital Image Processing（信息学院（信息学院 陈辉）陈辉）Optical IllusionsFill in non_existence/ wrongly perceive geometry.Elements of visual p erception no. 7 Digital Image Processing（信息学院（信息学院 陈辉）陈辉）Reading Questionsn What is Sampling ?nWhat is Quantization?nHow many samples are required for a good approximation?nHow many gray levels are required for a good approximation?