攝影機影像扭曲校正方法研究

The calibration methods of camera image distortion

林挺偉(Ting-Wei Lin)

指導教授 ： 張政元

中原大學/工學院/電機工程研究所/碩士(2009年)

https://doi.org/10.6840/CYCU.2009.00787

摘要

摘要

影像扭曲(Image Distortion)和雜訊(Noise)是攝影機影像最主要的問題。本論文針對視訊攝影機(Webcam)透鏡成像所產生的各種影像扭曲，以影像校正(Image Calibration)的方法來幫助我們可以獲得更正確的圖片資訊。影像校正方法包含最小均方根值(Least-Mean-Square, LMS)方法，和最小四方根法(Least-Mean-Fourth, LMF)，以及實數型基因演算法(Real-Parameter Genetic Algorithm, RGA)的影像校正方法，並與正交比(Cross-Ratio, CR)不變性影像校正做比較，一個選取初始值的方法也提出來加強校正的效果，第四章和第五章的實驗呈現比較有無加入初始值，對我們影像校正效能的影響。在實驗中，我們也透過自製的影像擷取介面方便我們從視訊攝影機獲得我們要的原始影像以及背景影像。
雜訊干擾部份我們採用了背景相減的方法降低雜訊量，另外，也提出一種簡單快速的消除雜訊的方式，使我們處理影像扭曲時得到的影像座標更加準確。

關鍵字

最小均方根 ； 影像校正 ； 視訊攝影機 ； 影像扭曲

並列摘要

Abstract

Distortion and noise are the main problem of CCD camera image. In this paper, the calibration methods of camera lens distortion are discussed. After calibration we can get the precise image information. We discussed many methods to do the image calibration. One is the least-mean-square (LMS) method to adjust the conservative inverse-distortion coefficients, also the least-mean-fourth (LMF) method, and also used the cross-ratio (CR) invariability method and real-parameter genetic algorithm (RGA). And we proposed the method of choose the best initial coefficients. In our experiments, we used the webcam to capture the distortion image and background image by the capture software. In the image processing of noise, we used the background subtraction to reduce the main noise. Besides, we proposed a simple method to do the noise cancellation. However, we compute the image coordinates without noise.

並列關鍵字

LMS ； webcam ； image distortion ； calibration

參考文獻

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