信息与物理工程学院中南大学认识自己难.pdf

信息与物理工程学院中南大学认识自己难 难于上青天 医学图像处理医学图像处理 Medical Image ProcessingMedical Image Processing Textbook 1 Digital image processing second edition written by R C Gonzalez 2 医学图像处理与分析 罗述谦等著 科学出版社 2003 UnRegistered 信息与物理工程学院中南大学认识自己难 难于上青天 Chapter1 Introduction One picture is worth more than ten thousand words Anonymous UnRegistered School of Info Physics and Geomatics Engineering CSU32009 3 16 Several objectives about this chapter define the scope of the field that we call image processing Give a historical perspective of the origins of this field Give an idea of the state of the art in image processing by examining some of the principal areas in which it is applied Discuss briefly the principal approaches used in digital image processing Give an overview of the components contained in a typical general goal image processing system Provide direction to the books and other literature where image processing work normally is reported UnRegistered School of Info Physics and Geomatics Engineering CSU42009 3 16 1 1 What is digital image processing DIP 1 Some relevant definitions of an image An image may be defined as a two dimensional function f x y where x and y are spatial coordinates and the amplitude of f at any point is called the intensity or gray level of the image at that point When x y and f are all finite discrete quantities we call the image a digital image A digital image is composed of a finite number of elements each of which is referred to as a picture element image element pel and pixel Vision of the human is limited to the visual band of electromagnetic EM spectrum but imaging machines can operate on all images generated by sources that include the entire EM spectrum ultra sound electron microscopy and computer generated images 2 The difference between DIP and computer vision The ultimate goal is to use computers to emulate human vision including learning and being able to make inferences and take actions base on visual inputs and itself is a branch of artificial intelligence AI UnRegistered School of Info Physics and Geomatics Engineering CSU52009 3 16 3 Three levels of DIP Usually DIP is considered three types of computerized processes but there are no clear cut boundaries in them a Low level processesinvolve primitive operations such as preprocessing to reduce noises contrast enhancement and image sharpening etc One such process is characterized by the fact that both its inputs and outputs are images b Mid level processing involves tasks such as segmentation description of those objects and classification recognition of individual objects Its characterization is that its inputs generally are images but its outputs are attributes extracted from those images e g edges contours and the identity of individual objects c High level processing involves make sensing or comprehension of an ensemble of recognized objects as in image analysis performing the cognitive functions normally associated with vision Refer to example at the bottom of page 2 UnRegistered School of Info Physics and Geomatics Engineering CSU62009 3 16 UnRegistered School of Info Physics and Geomatics Engineering CSU72009 3 16 UnRegistered School of Info Physics and Geomatics Engineering CSU82009 3 16 UnRegistered School of Info Physics and Geomatics Engineering CSU92009 3 16 UnRegistered School of Info Physics and Geomatics Engineering CSU102009 3 16 UnRegistered School of Info Physics and Geomatics Engineering CSU112009 3 16 1 2 A historical perspective of the origins about DIP Please see textbook at page3 7 Keynote 1 Three key supporting techniques date storage display and transmission 2 a series of key advances of computer 3 Space program started from the early 1960s 4 Application in Medical Imaging CAT or CT God N Hounsfield Allan M Cormack began in the late 1960s and early 1970s 5 Other application such as industry medicine biological science etc UnRegistered School of Info Physics and Geomatics Engineering CSU122009 3 16 1 3 Examples offields that use DIP The areas of application of digital image processing are so varied that it is difficult to include all context about this field One of the simplest way to develop a basic understanding of the extent of image processing applications is to categorize image according to their source Several forms of sources of energy are 1 Electromagnetic EM energy spectrum 2 Acoustic and ultrasonic imaging 3 Electronic microscopy imging 4 Synthetic images UnRegistered School of Info Physics and Geomatics Engineering CSU132009 3 16 1 3 1 imaging in the EM energy spectrum UnRegistered School of Info Physics and Geomatics Engineering CSU142009 3 16 Examples of gamma ray imaging left human bone scan right PET of a brain tumor and a lung tumor Image courtesy of G E medical system Dr Micheal E Casey CTI PET system UnRegistered School of Info Physics and Geomatics Engineering CSU152009 3 16 Examples of X ray imaging Up left chest X ray Dr David Down left aortic angiogram Dr Tomas Up right CT slice of Head Dr David UnRegistered School of Info Physics and Geomatics Engineering CSU162009 3 16 Examples of ultraviolet band imaging fluorescence microscope images UnRegistered School of Info Physics and Geomatics Engineering CSU172009 3 16 Examples of imaging in the visible and infrared bands UnRegistered School of Info Physics and Geomatics Engineering CSU182009 3 16 Multi spectral imaging UnRegistered School of Info Physics and Geomatics Engineering CSU192009 3 16 UnRegistered School of Info Physics and Geomatics Engineering CSU202009 3 16 UnRegistered School of Info Physics and Geomatics Engineering CSU212009 3 16 UnRegistered School of Info Physics and Geomatics Engineering CSU222009 3 16 UnRegistered School of Info Physics and Geomatics Engineering CSU232009 3 16 Examples of imaging in the microwave band radar UnRegistered School of Info Physics and Geomatics Engineering CSU242009 3 16 Examples of imaging in the radio band The major application of imaging in this band is in medicine MRI and astronomy UnRegistered School of Info Physics and Geomatics Engineering CSU252009 3 16 1 3 2 other imaging modalities acoustic imaging Application fields geological exploration low end of the sound spectrum hundreds of Hertz industry and medicine ultrasound millions of Hertz UnRegistered School of Info Physics and Geomatics Engineering CSU262009 3 16 electron microscopic imaging TEM transmission electron microscope SEM scanning electron microscope UnRegistered School of Info Physics and Geomatics Engineering CSU272009 3 16 computer generated images fractal and computer 3 D modeling UnRegistered School of Info Physics and Geomatics Engineering CSU282009 3 16 1 4 fundamental steps in DIP UnRegistered School of Info Physics and Geomatics Engineering CSU292009 3 16 1 5 components of an image processing system UnRegistered School of Info Physics