基于PC的不变矩实时计算算法(英文)

A PC-Based Real-Time Computation of Moment Invariants

矩和不变矩是工业部件识别和检测的重要特征.几何矩的值必须实时计算.介绍了灰度图像二维几何矩的高效计算.尽管存在许多矩快速计算算法,但不能在没有特殊硬件工具的微机上实时计算.原因是这些快速算法虽减少了计算复杂性,但在计算过程中仍需要大量浮点运算.为了实现在微机上的实时计算,提出的算法将图像分成相同大小的块,每图像块运用定点运算计算各自矩,然后运用浮点运算计算整个图像的矩.这种计算模式不需要近似而是精确计算,然而对于每个图像块不采用变换不容易克服溢出问题,在高效计算各图像块矩过程中使用了改进的Hatamian滤波器.实验结果表明,提出的算法大大减少了浮点运算次数,大大提高了图像矩计算速度.该算法可有效应用于复杂工业部件的实时识别和检测.

Moments and invariant moments are important features used in identification and inspection of industrial parts. It is necessary to compute geometric moment抯 values in real-time rate. The efficient computation of two-dimensional geometric moments on gray-level images is addressed in this paper. Despite the existence of many algorithms of fast computation of moments, it cannot be implemented for real-time computation to be run on a PC without the use of some special dedicated hardware tools. The reason beyond this is that those fast algorithms do reduce the complexity of computing but still one needs to use floating-point arithmetic operations in the computation process. To achieve real-time computation on a PC machine, what the algorithm suggested here is based on dividing the image into equally sized blocks. This algorithm works by computing local moments at each block using integer operations, then accumulating the total image moments with floating-point operations. With this computation scheme no approximation is used, it is an exact computation. Overcoming this overflow problem, however, is not straightforward without using some kind of transformation to each block. Hatamian抯 (improved) filter is used to compute those block moments (BLMs) efficiently. The experiments show that the algorithm presented in the paper has greatly reduced floating-point operations in fast computation of moments, and greatly improved the speed of the computation of moments. The new algorithm can be effectively used in real-time identification and inspection of complicated industrial parts.