Study on Enhancement of Weak-Radiometric Features Imagery
|School||PLA Information Engineering University|
|Course||Photogrammetry and Remote Sensing|
|Keywords||Weak Radiation Characteristic Image Image Enhance Dynamic RangeAdjustment Gamma Correction TV(Total Variation) PDE(Partial Differential Equation) Automatic White Balance|
Image enhancement technology plays a very important role to improve image quality inimage processing. Set out from the standpoint of engineering system，the image technique caninclude image processing，image analysis and image to comprehend three layers，but the contrastdegree of the image improvement，noise eliminate，get rid of to adjust with tone color etc whichshould belong to image processing in of prepare processing technique category. Aim at theweak-radiometric image，misty image，tone or color occurrence be partial to move a problemand investigate the mathematics model and processing technique of cleaning thesedisadvantageous factors and try hard for cancellation’s various interferences for remote sensingimage and make the sense of vision quality of image is promoted，this for image processingprinciple of expanding of thorough research and application realm，will have important theoryand realistic meaning.This text needle started putting forward a new vocabulary-weak radiation characteristicimage. Combine as to it’s carried on to elaborate. From three strengthen a technique to carry on aresearch to the images: The dynamic range of the image adjust，image of smoothing and noiseeliminate technique，the color image processing of automatic white balance. The combining gaveto carry out，among them include the Gamma Correction in non-linear transformations，smoothing and noise eliminate，white balance calculation，combined to apply actual image andplait distance experiment to verify the usefulness of each calculate way，Key job and innovationof thesis include:1、induce and tallied up the definition and content of weak radiation characteristicimage.The domestic and international research present condition that passes a related problemanalyzes a comparison，explicit the research topic of thesis，the sense of vision quality of namelyweak radiation characteristic image improves of basic calculate way research.2、Aim at a weak radiation characteristic grey degree the processing of the image, putforward to turn the cutting off of principle histogram well balanced to turn a method according tothe histogram well balanced, judge an original image through an auto distributing of dark pixelclearly all rate, carried out an effective automatic dynamic state scope adjustmentmethod.Improvement of Gamma not the line grey degree correct function, full in considerationof shadow area, brightsome and transition area these weak radiation characteristic district, adoptthe strategy that the different district adjusts each difference of range, direct according to extremelimit grey degree the proportion had by value pixel of oneself make sure to correct parameter andovercame the subjective of artificial choice parameter, carried out to correct to the automaticgrey degree of image. 3、In synthesizing analytical foundation of the image smooth calculate way of typicalmodel，variation problem with correspond of be partial to differential equation(PDE) contact toapply to image noise the processing that pick and get rid of a problem in. The whole variation ispartial to a differential equation to go to noise calculate way and absorbs to be partial to adifferential equation of each make use of polynomial to draw up the parameter of matching themethod superior choice to the opposite sex，in the smooth noise of nicely kept a target detail edgeat the same time，a little bit well solved the noise antinomy that represses and keeps a imagedetail.4、Studied a colorful image processing in of automatic white equilibrium calculate way.Thestability and applicability that synthesized to compare PR calculate way and QCGP calculateway from the objective and subjective evaluation and calculate way complications etc..Theexperiment discovers that if the brightest part of more accurate definition in the PR calculateway，or adjust the power of the GW calculate way and the PR calculate way in QCGP heavy，canraise the processing effect of colorful image automatic white balance further.5、 Carried on to the solution of above-mentioned problem concrete plait distanceexperiment, test result enunciation’s improvement calculate way to have promoting of greaterdegree to the visual effect of original image.