改进型图像中的直线快速检测

Improved fast line detection method in images

为提高数字图像中的直线的检测速度,从时频域变换和空间域变换两个角度出发,提出了一种改进型数字图像中直线快速检测方法。首先,采用小波提升提取图像中的低频轮廓信息,抑制高频噪声。然后,对像素降低后的图像进行二值化处理;基于"两点确定一条直线"以及Hough变换过程中"图像空间中一条直线上的多个点对应参数空间中一个点"的原理,按照从局部到整体的检测顺序,将二值化后图像空间中的非零点映射到参数空间中具有较大存在概率的累加单元,而不是所有可能的累加单元。最后,对累加单元进行统计,以确定图像中直线的参数。利用该方法对一幅像素为128×128的数字图像进行直线检测,耗时为213ms。该方法有效地提高了数字图像中直线检测的实时性。

In order to improve the detection speed for lines in digital images,an improved detection method was proposed by combining the time-frequency domain transform and the spatial domain transform.Firstly,the wavelet lifting was used to extract the low frequency profile information and to restrain high frequency noises.Then,the gradient of a image was computed to obtain a binary image.On the basis of the principles that a line can be determined by two points and a line in the image is mapped to a point in the Hough Transform,the non-zero pixels were mapped into the accumulator cells with great probability instead of all accumulator cells following the detection sequence from the local to the global.Finally,the accumulator cells were counted to determine the parameters of lines in the image.It costs 213 ms to detect lines in the image with pixels of 128×128 by using the method proposed in this paper,which increases the detection speed for lines in images effectively.