二维不变矩在图像识别中的应用

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"这篇文章深入探讨了视觉模式识别中的二维不变矩理论,主要关注这些不变矩在平面几何图形识别中的应用。作者Ming-Kuei Hu在1962年的IRE Transactions on Information Theory上发表了这一研究,提出了一个关联二维不变矩与代数不变量的基本定理,并构建了在平移、相似和正交变换下的不变矩完整系统。此外,还讨论了一些在二维线性变换下的不变矩。该研究不仅涵盖了理论框架,还提到了基于这些不变矩的实际模式识别模型和一个简单的模拟程序,证明了即使在位置、大小和方向变化的情况下,也能实现几何图形和字母字符的识别。文章指出,通过平行投影,还可以实现更广泛的不变性。” 在图像处理和计算机视觉领域,不变矩是一个关键概念,它们是图像特征的一种度量,可以在图像经过某些变换后保持不变。本文的核心贡献在于建立了二维不变矩与代数不变量之间的联系,这对于模式识别至关重要,因为它们允许系统识别经过不同变换后的相同模式。平移不变性意味着无论图案在图像中的位置如何变化,都能被正确识别;相似变换不变性则确保了图案的缩放和旋转不会影响识别结果;正交变换不变性则进一步扩展到镜像等操作。 作者通过推导出这些变换下的完整不变矩系统,为视觉模式识别提供了坚实的理论基础。这使得算法能够对图像进行抽象,提取出不依赖于具体几何属性(如位置、大小和方向)的特征,从而实现更准确的匹配和分类。 此外,文中提到的简单模拟程序展示了这种理论在实践中的应用,通过其性能分析,证明了使用不变矩方法可以有效地识别几何形状和字母字符,不论其在图像中的位置、尺寸或角度如何。最后,文章提出,通过平行投影的不变性,可以进一步扩大这种方法的应用范围,使其适应更复杂的场景。 这篇论文对视觉模式识别领域产生了深远影响,为后续的图像分析和模式识别算法设计提供了重要的理论工具和技术参考。不变矩的概念至今仍广泛应用于图像识别、物体检测和机器学习等诸多领域,体现了其持久的价值和实用性。
2010-08-25 上传
Moments as projections of an image’s intensity onto a proper polynomial basis can be applied to many different aspects of image processing. These include invariant pattern recognition, image normalization, image registration, focus/ defocus measurement, and watermarking. This book presents a survey of both recent and traditional image analysis and pattern recognition methods, based on image moments, and offers new concepts of invariants to linear filtering and implicit invariants. In addition to the theory, attention is paid to efficient algorithms for moment computation in a discrete domain, and to computational aspects of orthogonal moments. The authors also illustrate the theory through practical examples, demonstrating moment invariants in real applications across computer vision, remote sensing and medical imaging. Key features: Presents a systematic review of the basic definitions and properties of moments covering geometric moments and complex moments. Considers invariants to traditional transforms – translation, rotation, scaling, and affine transform - from a new point of view, which offers new possibilities of designing optimal sets of invariants. Reviews and extends a recent field of invariants with respect to convolution/blurring. Introduces implicit moment invariants as a tool for recognizing elastically deformed objects. Compares various classes of orthogonal moments (Legendre, Zernike, Fourier-Mellin, Chebyshev, among others) and demonstrates their application to image reconstruction from moments. Offers comprehensive advice on the construction of various invariants illustrated with practical examples. Includes an accompanying website providing efficient numerical algorithms for moment computation and for constructing invariants of various kinds, with about 250 slides suitable for a graduate university course. Moments and Moment Invariants in Pattern Recognition is ideal for researchers and engineers involved in pattern recognition in medical i