计算机应用 ›› 2015, Vol. 35 ›› Issue (5): 1444-1448.DOI: 10.11772/j.issn.1001-9081.2015.05.1444

• 虚拟现实与数字媒体 • 上一篇    下一篇

单幅圆形鱼眼图像的校正

张军, 王志舟, 杨正瓴   

  1. 天津大学 电气与自动化工程学院, 天津 300072
  • 收稿日期:2014-12-17 修回日期:2015-01-27 出版日期:2015-05-10 发布日期:2015-05-14
  • 通讯作者: 王志舟
  • 作者简介:张军(1964-),男,天津人,副教授,硕士,主要研究方向:智能交通系统、计算机视觉与图像处理; 王志舟(1991-),男,山西朔州人,硕士研究生,主要研究方向:数字图像处理; 杨正瓴(1964-),男,河北灵寿人,副教授,博士,主要研究方向:复杂时间序列预测、人工智能、混沌理论.
  • 基金资助:

    天津市创新基金资助项目(13ZXCXGX40500);天津市小巨人创新基金资助项目(2012-XJR21017).

Correction of single circular fisheye image

ZHANG Jun, WANG Zhizhou, YANG Zhengling   

  1. School of Electrical Engineering and Automation, Tianjin University, Tianjin 300072, China
  • Received:2014-12-17 Revised:2015-01-27 Online:2015-05-10 Published:2015-05-14

摘要:

针对有效圆域提取不准确以及传统柱面投影校正法在垂直方向上校正视场角不能达到180°的问题,分别提出了变角度线扫描法和纵向压缩柱面投影校正法.前者通过不断改变扫描线的倾斜角来寻找切点坐标,并对无效切点进行滤除,然后使用Kasa圆拟合法求取有效圆域的参数.后者则对传统柱面投影的光路进行了人为的弯折,从而把投影到无穷远点的光线压缩回柱面上,保留了图像有效信息.通过与经纬映射校正法以及墨卡托投影法的实验处理结果对比,纵向压缩柱面投影法能弱化校正图像边缘的拉伸模糊效应,使处理结果更加自然.

关键词: 鱼眼图像, 校正, 变角度线扫描, 纵向压缩, 柱面投影

Abstract:

Focused on the issues that circular domain extraction is not accurate and effective correction field angle can not reach 180 degrees in the vertical direction, Variable Angle Line Scan (VALS) method and Longitudinal Compression Cylindrical Projection (LCCP) method were proposed respectively. By changing the inclination angle of the scan line, the VALS method got coordinates of those cut points, then it filtered out invalid cut points coordinates and further got the parameters of the circular domain by using the Kasa circle fitting method. As for the LCCP method, it artificially bended the optical path of traditional cylindrical projection so that the light projected onto the infinity point could be projected back on the cylindrical surface, thus preserved the image information effectively. The comparison with two known methods named longitude-latitude mapping and Mercator mapping proves the effectiveness of the proposed algorithm in weakening the blurring effect due to stretching caused by the edge of image correction. The result looks more nature.

Key words: fisheye image, correction, variable angle line scan, longitudinal compression, cylindrical projection

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