摘要
在管道内壁形貌检测系统中,由全景环形透镜(PAL)组成的观测系统在没有活动部件的条件下,能够同时观测到绕光轴360°的物体,并且由于其独特的成像性能,能够产生一个环形像。但是所成环形像不便于人眼观察和测量,有畸变和失真。为此将环形像无失真地展开为常规平面像,需要解决环形像由外到内压缩引起的分辨率降低的问题。根据PAL成像的特点,以全景图像的最高分辨率为基准,采用一种基于边缘检测的插值方法,对边缘部分采用三次卷积插值法,非边缘区域采用双线性插值,此结果同双线性插值和三次卷积插值进行比较,较好地恢复了图像细节,同时减小了图像复原的计算量。
In the detection of the feature of the pipeline wall, the observing system made up of PAL can observe objects around the lens without moving parts, and for the special imaging feature of PAL, that can form an annular image. But the annular image formed by PAL is not only unconvenient for observation and measurement,but also has distortion phenomenon. Thus an annular image from PAL needs to be unwrapped to conventional rectangular image without distortion, the problem of the decreased resolution from outer circles to inner ones needs to be resolved during unwrapping procedure. The PAL image is restored according to the imaging feature of panoramic annular lens, referenced to the highest resolution, adopt an interpolation method based on edge detection which adopts cubic convolution interpolation for edge and bilinear interpolation for non-edge. Compared with bilinear interpolation and cubic convolution interpolation, this method can restore the detail of the image better and decrease the computational cost.
出处
《计算机技术与发展》
2009年第3期59-61,65,共4页
Computer Technology and Development
关键词
全景环形透镜
环形像
边缘检测
双线性插值
三次卷积插值
panoramic annular lens（PAL）
annular image
edge detection
bilinear interpolation
cubic convolution interpolation
