计算机技术与发展
計算機技術與髮展
계산궤기술여발전
COMPUTER TECHNOLOGY AND DEVELOPMENT
2014年
5期
164-167,172
,共5页
陈银平%涂碧海%张毅%陈立刚%洪津
陳銀平%塗碧海%張毅%陳立剛%洪津
진은평%도벽해%장의%진립강%홍진
偏振定标%绝对角度%高斯拉普拉斯算子%椭圆对称%一阶导阈值%霍夫变换
偏振定標%絕對角度%高斯拉普拉斯算子%橢圓對稱%一階導閾值%霍伕變換
편진정표%절대각도%고사랍보랍사산자%타원대칭%일계도역치%곽부변환
polarization calibration%absolute angle%Laplacian of Gaussian%elliptical symmetry%threshold of first derivative%Hough trans-form
光学成像系统自身通常都具有一定的偏振效应,严重影响仪器偏振测量精度,而提高仪器中偏振片绝对角度精度能提高偏振定标精度,对校正光学系统自身的偏振特性具有重要的意义。对偏振片直线透光轴Raw图像高精度边缘定位和直线检测是偏振片绝对角度计算的关键步骤。针对传统LOG算子各向同性及虚假边缘与边缘定位精度相矛盾的缺陷,提出改进型一阶导阈值旋转式椭圆对称LOG算子。该算子不仅保留了经典LOG算子的优点,还具有对不同角度的边缘更加有效地进行检测,在保持边缘定位精度下,减少虚假边缘的特点。在处理得到的边缘二值图像上,进行直线检测求出偏振片绝对角度,通过对比分析最小二乘法线性拟合和霍夫变换的直线检测效果,得出霍夫变换能精确计算出偏振片绝对角度。实验证明改进型LOG算子与霍夫变换相结合提高了偏振片绝对角度测量精度,对偏振定标精度具有很大的提高。
光學成像繫統自身通常都具有一定的偏振效應,嚴重影響儀器偏振測量精度,而提高儀器中偏振片絕對角度精度能提高偏振定標精度,對校正光學繫統自身的偏振特性具有重要的意義。對偏振片直線透光軸Raw圖像高精度邊緣定位和直線檢測是偏振片絕對角度計算的關鍵步驟。針對傳統LOG算子各嚮同性及虛假邊緣與邊緣定位精度相矛盾的缺陷,提齣改進型一階導閾值鏇轉式橢圓對稱LOG算子。該算子不僅保留瞭經典LOG算子的優點,還具有對不同角度的邊緣更加有效地進行檢測,在保持邊緣定位精度下,減少虛假邊緣的特點。在處理得到的邊緣二值圖像上,進行直線檢測求齣偏振片絕對角度,通過對比分析最小二乘法線性擬閤和霍伕變換的直線檢測效果,得齣霍伕變換能精確計算齣偏振片絕對角度。實驗證明改進型LOG算子與霍伕變換相結閤提高瞭偏振片絕對角度測量精度,對偏振定標精度具有很大的提高。
광학성상계통자신통상도구유일정적편진효응,엄중영향의기편진측량정도,이제고의기중편진편절대각도정도능제고편진정표정도,대교정광학계통자신적편진특성구유중요적의의。대편진편직선투광축Raw도상고정도변연정위화직선검측시편진편절대각도계산적관건보취。침대전통LOG산자각향동성급허가변연여변연정위정도상모순적결함,제출개진형일계도역치선전식타원대칭LOG산자。해산자불부보류료경전LOG산자적우점,환구유대불동각도적변연경가유효지진행검측,재보지변연정위정도하,감소허가변연적특점。재처리득도적변연이치도상상,진행직선검측구출편진편절대각도,통과대비분석최소이승법선성의합화곽부변환적직선검측효과,득출곽부변환능정학계산출편진편절대각도。실험증명개진형LOG산자여곽부변환상결합제고료편진편절대각도측량정도,대편진정표정도구유흔대적제고。
Optical imaging system itself generally exhibits inevitable polarization effects that seriously affect the instrument's polarization measurement accuracy. To improve accuracy of the instrument's absolute angle of polarizer can improve accuracy of polarization calibra-tion and it has a significance to correct optical polarization characteristics of the system. Precision edge location and line detection of raw image of polarizer's linear transmission axis are the key steps in computing the absolute angle of polarizer. For traditional LOG operator, it has defects of isotropic and false edge which is in contradiction with the accuracy of edge positioning. In order to solve these defects, propose an improved LOG operator called as the threshold of first derivative rotary elliptical symmetry LOG operator. The operator not only retains the advantages of classical LOG operator,but also has the advantage to detect edges of different angles more efficiently and reduce the quantity of false edges with maintaining the accuracy of edge's positioning. Line detection operation is taken on the binary im-age after edge detection to computing absolute angle of polarizer. By analyzing and comparing results of line detection of least-squares linear fitting and Hough transform,it is known that Hough transform can accurately calculate the absolute angle of polarizer. Experiments show that improved LOG operator combined with Hough transform can enhance the accuracy of absolute angle of polarizer and the cali-bration accuracy of polarization.