电子测量与仪器学报
電子測量與儀器學報
전자측량여의기학보
JOURNAL OF ELECTRONIC MEASUREMENT AND INSTRUMENT
2014年
11期
1262-1267
,共6页
卢家亮%鲁昌华%蒋薇薇%陶志颖%查正兴
盧傢亮%魯昌華%蔣薇薇%陶誌穎%查正興
로가량%로창화%장미미%도지영%사정흥
数字摄像%能见度仪%白天能见度%透射率估计
數字攝像%能見度儀%白天能見度%透射率估計
수자섭상%능견도의%백천능견도%투사솔고계
digital photography%visibility instrument%daytime visibility%transmittivity estimation
数字摄像法测量白天大气能见度,常用的方法是双亮度差法,此方法需尽可能保证标准的观测条件,例如两组目标-背景视线方向一致,尽量选择观测反射率低得可以忽略的人工实用黑体目标物等,否则会产生较大的误差。为此设计了一种新的基于数字摄像机的白天能见度算法:拍摄包含合适的目标物和天空背景图像,通过暗原色先验估计透射率,通过调节光圈大小获得散焦图像,把S变换应用到图像处理中,计算视觉距离,可以得出大气消光系数,从而反演出大气能见度值。实验数据表明,该算法在能见度的值在4000~8000 m范围内最大误差小于9%,测量结果比双亮度差方法误差减小2.1%~3.4%。
數字攝像法測量白天大氣能見度,常用的方法是雙亮度差法,此方法需儘可能保證標準的觀測條件,例如兩組目標-揹景視線方嚮一緻,儘量選擇觀測反射率低得可以忽略的人工實用黑體目標物等,否則會產生較大的誤差。為此設計瞭一種新的基于數字攝像機的白天能見度算法:拍攝包含閤適的目標物和天空揹景圖像,通過暗原色先驗估計透射率,通過調節光圈大小穫得散焦圖像,把S變換應用到圖像處理中,計算視覺距離,可以得齣大氣消光繫數,從而反縯齣大氣能見度值。實驗數據錶明,該算法在能見度的值在4000~8000 m範圍內最大誤差小于9%,測量結果比雙亮度差方法誤差減小2.1%~3.4%。
수자섭상법측량백천대기능견도,상용적방법시쌍량도차법,차방법수진가능보증표준적관측조건,례여량조목표-배경시선방향일치,진량선택관측반사솔저득가이홀략적인공실용흑체목표물등,부칙회산생교대적오차。위차설계료일충신적기우수자섭상궤적백천능견도산법:박섭포함합괄적목표물화천공배경도상,통과암원색선험고계투사솔,통과조절광권대소획득산초도상,파S변환응용도도상처리중,계산시각거리,가이득출대기소광계수,종이반연출대기능견도치。실험수거표명,해산법재능견도적치재4000~8000 m범위내최대오차소우9%,측량결과비쌍량도차방법오차감소2.1%~3.4%。
The common method for testing daytime visibility by digital photography is dual differential luminance al-gorithm, which asks for standard observation conditions.For example, the two groups of target-background view should be in the same direction and the researcher should try to choose black practical man-made object target to observe, whose reflectivity should be low enough to ignore.Otherwise, serious error will be made.Thus, a new daytime visibility algorithm based on digital camera is proposed , which contains the appropriate object and sky background image.The result of atmospheric visibility could be obtained by estimating transmittance based on dark channel priority and adjusting the camera aperture size to get defocused images, and then the S transform is applied for image processing to computer vision distance to derive atmospheric extinction coefficient values .The experimen-tal data shows that the maximum error of the proposed algorithm is less than 9% in visibility observation range 4 000~8 000 m.This algorithm can make the error of dual differential luminance algorithm reduced by 2.1%~3.4%.