1、英文资料翻译 Image processing is not a one step process We are able to distinguish between several steps which must be performed one after the other until we can extract the data of interest from the observed scene In this way a hierarchical processing scheme is built up as sketched in Fig The figure give
2、s an overview of the different phases of image processing. Image processing begins with the capture of an image with a suitable， not necessarily optical， acquisition system In a technical or scientific application， we may choose to select an appropriate imaging system Furthermore， we can set up the
3、illumination system， choose the best wavelength range， and select other options to capture the object feature of interest in the best way in an image Once the image is sensed， it must be brought into a form that can be treated with digital computers.This process is called digitization. With the prob
4、lems of traffic are more and more serious. Thus Intelligent Transport System (ITS) comes out. The subject of the automatic recognition of license plate is one of the most significant subjects that are improved from the connection of computer vision and pattern recognition. The image imputed to the c
5、omputer is disposed and analyzed in order to localization the position and recognition the characters on the license plate express these characters in text string form The license plate recognition system (LPSR) has important application in ITS. In LPSR, the first step is for locating the license pl
6、ate in the captured image which is very important for character recognition. The recognition correction rate of license plate is governed by accurate degree of license plate location. In this paper, several of methods in image manipulation are compared and analyzed, then come out the resolutions for
7、 localization of the car plate. The experiences show that the good result has been got with these methods. The methods based on edge map and frequency analysis is used in the process of the localization of the license plate, that is to say, extracting the characteristics of the license plate in the
8、car images after being checked up for the edge, and then analyzing and processing until the probably area of license plate is extracted. The automated license plate location is a part of the image processing ,its also an important part in the intelligent traffic system It is the key step in the Vehi
9、cle License Plate Recognition(LPR).A method for the recognition of images of different backgrounds and different illuminations is proposed in the paper.the upper and lower borders are determined through the gray variation regulation of the character distribution.The left and right borders are determ
10、ined through the black-white variation of the pixels in every row. The first steps of digital processing may include a number of different operations and are known as image processing If the sensor has nonlinear characteristics, these need to be corrected Likewise， brightness and contrast of the ima
11、ge may require improvement Commonly， too， coordinate transformations are needed to restore geometrical distortions introduced during image formation Radiometric and geometric corrections are elementary pixel processing operations It may be necessary to correct known disturbances in the image， for in
12、stance caused by a defocused optics， motion blur， errors in the sensor， or errors in the transmission of image signals We also deal with reconstruction techniques which are required with many indirect imaging techniques such as tomography that deliver no direct image. A whole chain of processing ste
13、ps is necessary to analyze and identify objects First， adequate filtering procedures must be applied in order to distinguish the objects of interest from other objects and the background Essentially， from an image（ or several images）， one or more feature images are extracted The basic tools for this
14、 task are averaging and edge detection and the analysis of simple neighborhoods and complex patterns known as texture in image processing An important feature of an object is also its motion Techniques to detect and determine motion are necessary Then the object has to be separated from the backgrou
15、nd This means that regions of constant features and discontinuities must be identified This process leads to a label image Now that we know the exact geometrical shape of the object， we can extract further information such as the mean gray value， the area， perimeter， and other parameters for the for
16、m of the object3 These parameters can be used to classify objects This is an important step in many applications of image processing， as the following examples show： In a satellite image showing an agricultural area， we would like to distinguish fields with different fruits and obtain parameters to
17、estimate their ripeness or to detect damage by parasites There are many medical applications where the essential problem is to detect pathologi-al changes A classic example is the analysis of aberrations in chromosomes Character recognition in printed and handwritten text is another example which ha
18、s been studied since image processing began and still poses significant difficulties You hopefully do more， namely try to understand the meaning of what you are reading This is also the final step of image processing， where one aims to understand the observed scene We perform this task more or less
19、unconsciously whenever we use our visual system We recognize people， we can easily distinguish between the image of a scientific lab and that of a living room， and we watch the traffic to cross a street safely We all do this without knowing how the visual system works For some times now， image proce
20、ssing and computer-graphics have been treated as two different areas Knowledge in both areas has increased considerably and more complex problems can now be treated Computer graphics is striving to achieve photorealistic computer-generated images of three-dimensional scenes， while image processing i
21、s trying to reconstruct one from an image actually taken with a camera In this sense， image processing performs the inverse procedure to that of computer graphics We start with knowledge of the shape and features of an objectat the bottom of Fig. and work upwards until we get a two-dimensional image
22、 To handle image processing or computer graphics， we basically have to work from the same knowledge We need to know the interaction between illumination and objects， how a three-dimensional scene is projected onto an image plane， etc There are still quite a few differences between an image processin
23、g and a graphics workstation But we can envisage that ， when the similarities and interrelations between computergraphics and image processing are better understood and the proper hardware is developed， we will see some kind of general-purpose workstation in the future which can handle computer grap
24、hics as well as image processing tasks5 The advent of multimedia， i. e. ， the integration of text， images，sound， and movies， will further accelerate the unification of computer graphics and image processing. In January 1980 Scientific American published a remarkable image called Plume2， the second o
25、f eight volcanic eruptions detected on the Jovian moon by the spacecraft Voyager 1 on 5 March 1979 The picture was a landmark image in interplanetary explorationthe first time an erupting volcano had been seen in space It was also a triumph for image processing Satellite imagery and images from inte
26、rplanetary explorers have until fairly recently been the major users of image processing techniques， where a computer image is numerically manipulated to produce some desired effect-such as making a particular aspect or feature in the image more visible. Image processing has its roots in photo recon
27、naissance in the Second World War where processing operations were optical and interpretation operations were performed by humans who undertook such tasks as quantifying the effect of bombing raids With the advent of satellite imagery in the late 1960s， much computer-based work began and the color c
28、omposite satellite images， sometimes startlingly beautiful, have become part of our visual culture and the perception of our planet Like computer graphics， it was until recently confined to research laboratories which could afford the expensive image processing computers that could cope with the sub
29、stantial processing overheads required to process large numbers of high-resolution images With the advent of cheap powerful computers and image collection devices like digital cameras and scanners， we have seen a migration of image processing techniques into the public domain Classical image process
30、ing techniques are routinely employed by graphic designers to manipulate photographic and generated imagery， either to correct defects， change color and so on or creatively to transform the entire look of an image by subjecting it to some operation such as edge enhancement. A recent mainstream appli
31、cation of image processing is the compression of imageseither for transmission across the Internet or the compression of moving video images in video telephony and video conferencing Video telephony is one of the current crossover areas that employ both computer graphics and classical image processing techniques to try to achieve very high compression rates All this is part of an inexorable trend towards the digital representation of images Indeed that most powerful image form of the twentieth centurythe TV imageis also about to be taken into the digital domain
