DINAME 2007
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1. Ea ___ _ Figure 2 Experimental apparatus The central idea is to develop one simple and not so expensive imagine acquisition system The early listed items considering medium configuration are very cheap Basically hardware to capture images and after perform automated image processing on the acquired image through software The next section detailed description about software development 3 THE SOFTWARE Figure 3 shows the fluxogram of the program First is necessary to acquire one video These occur because the frame grabber available has not on board memory In the next step this video can be divided in frames images These images follow to treatment The treatment includes the possibility of to obtain threshold histogram or average of images acquired Images Treatment Video Acquisition Threshold Histogram Average Transformation of Video to Images Image Treatment Figure 3 Software fluxgram The following paragraphs details about the program Graphical User Interface The User Graphical Interface is a hybrid of the image acquisition and the processing image Figure 4 shows the completed VI that will be used during testing of the Image Acquisition In left shows Video Acquisition and in right already in processing section Add Images This single program know as a virtual instrument VI in LabVIEW will control the entire system from startup to shutdown when the user to fin2. Proceedings of COBEM 2007 19 International Congress of Mechanical Engineering Copyright 2007 by ABCM November 5 9 2007 Brasilia DF DEVELOP OF IMAGE ACQUISITION SOFTWARE Rafael Simonetti Assim Instituto Tecnol gico de Aeronautica Sao Jos dos Campos SP rafaelassim yahoo com br Gl vson Diniz Franco Instituto Tecnol gico de Aeronautica Sao Jos dos Campos SP glevson hotmail com Jos Roberto Instituto S o Jos dos Campos SP jose roberto 1ae cta br Daniel Martins Instituto Tecnol gico de Aeronautica Sao Jos dos Campos SP daniel_mat hotmail com Cristiane A Martins Instituto Tecnol gico de Aeronautica Sao Jos dos Campos SP cmartins ita br Abstract Intrusive and non intrusive methods has been utilized for study of several physical phenomena The first generally more cheap do not have higher neither spatial nor temporal resolution The other however are in several times expensive techniques once that sometimes includes instruments how lasers ICCD and so on This work focus in develop of the software image acquisition and eventually shows one application The hardware include CCD camera lens and suitable filters besides one cheap commercial frame grabber The software utilized Graphical language LabVIEW with image package include Keywords Image acquisition software LabVIEW 1 INTRODUCTION At second semester of 2006 inside of course Introduction to the Acquisition Data S
3. are much simpler than those for analog video since the signal is already digitized Digital frame grabber needs to be configurable in order to be compatible with all the different scanning conventions available Besides image acquisition could occur with onboard memory not dependent of the system memory Onboard memory became useful when there is a lot of traffic across the computer s PCI bus Transferring images using an on board acquisition is slower than a system memory acquisition because on board image acquisition use Interrupt IO transfers and system memory acquisitions use DMA transfers Some applications require on board acquisition The PCI bus can only sustain 100 MB sec but the there are onboard system with capacity to acquire up to 200MB sec 32 bits pixel with a 50MHz pixel clock Using onboard memory allows the user to save the high speed event in onboard memory since the PCI bus can not handle 200MB sec sustained The system could save up to 80MB of image data and then the user could acquire these images from the high speed event and transfer them to system memory across the PCI bus more slowly and all the high speed images would be saved on the IMAQ devices on board memory This is implemented with an on board sequence acquisition Acquisition into Onboard Memory 2006 In resume one complete image system includes both hardware and software both with specifics characteristics Hardware e Vision camera The camera analog or digita
4. evious video file in AVI format As mentioned this frame could be saved at different images formats Thresholding Several times the images were corrupted by noise during its acquisition and transmission Denoising is a main work in many image processing applications The goal of this is to remove the noise while keeping the important image features as much as possible It is usual image denoising using nonlinear filter Thresholding algorithm is an orthogonal transform domain such is a subband or wavelet transform is a nonlinear filter Guangmin and Fudong 2003 Image Search In a typical vision application it is possible to extract measurements from ROIs Region Of Interest rather than the entire image To use this the parts of the object of the interest in must always appear inside the ROIs previously defined Histogram The histogram interpretation is the most important concept in order to working images A histogram can indicate whether the image acquired has been properly exposed whether the lighting is harsh or flat and what adjustments will be necessary This program was developed to generate the histogram of frequency of an image This it will possibility better choice more appropriate of the level which will utilized for the thresholding The histogram plots the number of pixels in the image vertical axis with a particular brightness value horizontal axis Image Average Takes the sum of pixel value from the specified numbe
5. flame picture take to digital camera Sony Cyber Shot Figure 6 Picture of flame take to Digital Sony Cyber Shot model Figure 7 the same flame with the system descript in this work Imaging takes without filter Figure 7 Picture of flame utilizing image system develop Figure 8 the image was acquired in wavelength of the 432 22nm Proceedings of COBEM 2007 19 International Congress of Mechanical Engineering Copyright 2007 by ABCM November 5 9 2007 Brasilia DF Figure 8 CH radical emission 4 CONCLUSION This primary goal in this work was develop one simple and reliable image system acquisition as same easy to operate Throughout the design and implementation was necessary to utilized multidisciplinary academic foundation includes instrumentation knowledge The objective was achieved and one of them possible application was demonstrated Here how example chemiluminescence emissions from CH free radicals were acquired with a CCD camera and the image was analyzed utilizing the develop program 5 REFERENCES LabVIEW Student Edition Version 7 1 1 Serial Number S79E27423 Acquisition into Onboard Memory 2006 http zone ni com devzone cda tut p id 2696 IMAQ Vision for LabVIEWTM User Manual IMAQ Vision for LabVIEW User August 2004 Edition Guangmin S and Fudong L Image Denoising with Optimized Subband Threshold Proceedings of the Fifth International Conference on Computational Intelligence and Multimedia Applica
6. ished the image treatment In order to accomplish this there are several controls and data indicators to be displaced on one screen for the user As mentioned it was necessary to utilize the IMAQ Vision Package joint to LabVIEW software This package could be thought how an additional tool of LabVIEW IMAQ Vision for LabVIEW is organized into four main function palettes Imaq Acquisition Vision Utilities Image Processing and Machine Vision Imaq Acquisition has functions utilized to acquire image from external device Vision Utilities functions allow to manipulate and display images in IMAQ Vision Image Processing use functions to analyze filter and process images Machine Vision VIs are high level VIs The last is able to simplify common machine vision tasks Details can be obtained IMAQ Vision for LabVIEW User Manual 2004 Figure 4 Completed VI for Image Acquisition Proceedings of COBEM 2007 19 International Congress of Mechanical Engineering Copyright 2007 by ABCM November 5 9 2007 Brasilia DF Multiples functions of the IMAQ Vision Package were utilized during program development The result was the following possibilities Video Acquisition or Image Acquisition The purpose is to acquire videos only in AVI format Images format however could be saves as BMP TIF JPG or GIF formats This was possible because one suitable subroutine was building for this task Frames Acquisition Permit to take some frame from pr
7. l must have suitable parameters according your frame grabber capacity The camera manufacturer is responsible for to provide documentation detailing the properties in each attribute e Frame Grabber There are thousands of models and the user must to define one compatible with their necessity Proceedings of COBEM 2007 19 International Congress of Mechanical Engineering Copyright 2007 by ABCM November 5 9 2007 Brasilia DF Software e Vision Acquisition Software Normally the frame grabber manufacture supply some simply software which generally is able only to capture images User is then responsible for development some useful software sometimes in Language C When possible is more easy for user to acquire some suitable and friendly software The more important matter is that the software and hardware necessarily must be compatible Unfortunately this not always it is occur Now it considering that the hardware and software was correctly installed without any conflict between them the next step is to configure the camera and to start up image acquisition In this work the following system was utilized Camera CCD Marshall Camera 8 bits 520 x 480 pixels Frame Grabber PCI 1405 Single Channel Color Monochrome Frame Grabber National Instruments Software LabVIEW Student Edition Version 7 1 1 and the IMAQ Vision package evaluation Figure 2 shows the experimental apparatus SS EGE AAA 0A AENEAS TR 5 3 4 n S a 19 4 a
8. ments and necessity of the have domain over their 2 IMAGE ACQUISITION SYSTEM In order to obtain any image is necessary one suitable system This includes camera frame grabber and software with capacity to interact with both The frame grabber is installed in PC bus and has one appropriate connector with camera for example BNC or an RCA connector output The next paragraph the resume for explain the purpose of the frame grabber An image can be thinking up as a two dimensional array of intensity or color data A camera however outputs a one dimensional stream of analog or digital data The purpose of the frame grabber is to acquire this data digitize them if necessary and organize them properly for transfer them across of the PCI bus or other bus into system memory from where it can be displayed as an image In order to understand this process and to be able of troubleshooting display problems one must to know the exact structure of the video signal which would be acquired Table 1 describes some characteristics of the standard analog video formats in common use today Table 1 Standard Analog Video Formats Format Country Mode Signal Frame Rate Vertical Line Rate Name frame sec Line lines sec Resolution NTSC US Japan RS 170 15 750 640x480 NTSC Color 29 97 15 734 0 PAL Europe CCIR 10 125 768x576 except Color PAL Color 25 625 15 625 France 19 SECAM France Mono 25 89 20 475 N A Europe Digital video
9. r of scan and use arithmetic as the final value in the image In this way is possible to preserve those persistent pixel values that are mostly specific signal while divide away along times those fluctuated values that are mostly noise Average is able to reduces noise and improve image quality The full program program source code includes different functions how can be visualized in Figure 5 iaaea vir Velo para angquivar ss bmages Ue ry Path of S col f i Frien a cer piar Lalas at magany i T E eae u Frane majal para squab Figure 5 LabVIEW program source code 4 APPLICATION EXAMPLE This sections shows one application example which the early develop program descript was utilized Here the intention is shows how can to be utilized for example for to study the radical emission in one natural gas flame In chemistry free radicals are atomic or molecular species with unpaired electrons or an otherwise open shell configuration Unpaired electrons make the species more attracted to a magnetic field they are said to be paramagnetic This gives free radicals a highly reactive nature They are capable of independent existence and act as intermediates in chemical reactions Although they have the ability to exist independently they usually have a fleeting existence Free radicals play an important role in combustion atmospheric chemistry and many other chemical processes Figure 6 shows the
10. tions ICCIMA 03 2003 6 RESPONSIBILITY NOTICE The authors are the only responsible for the printed material included in this work
11. ystems the topic Image Acquisition was given as the final exam The main motivation is to visualize and to acquire images with different format utilizing Image Processing tools inside of LabVIEW Student Version 7 0 Student Version is more cheap and of course more limited The main idea was acquire an image with a camera through suitable acquisition device load an image from a file store on hard disk or convert the data stored in a 2D array to an image or vice verse Initial cares before the image acquisition are essential in order to obtain the most accurate measurements Among them is the exact knowledge of your equipment if it is able to capture your object of the appropriate manner Also camera position need to perpendicular to the object under inspection This is essential because if your camera acquires images of the some object from an angle will be occur perspective errors Figure 1 present an example of the CCD camera utilized at flame studies Alter Figure 1 Image acquisition application In example before it is possible through image to obtain radicals profile how C2 CH CN OH and NO profiles These data could be after care analysis for example to be eventually correlates with pollutants emissions The great advantage of the image acquisition system is that is possible to obtain information without any physical contact with the phenomena In this way some errors are avoid In the order hand in most time there is sophisticate equip
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