特征检测和描述符提取有什么区别? [英] What is the difference between feature detection and descriptor extraction?

问题描述

有人知道 OpenCV 2.3 中特征检测和描述符提取之间的区别吗?

Does anyone know the difference between feature detection and descriptor extraction in OpenCV 2.3?

我了解使用 DescriptorMatcher 进行匹配需要后者.如果是这样，FeatureDetection 是做什么用的?

I understand that the latter is required for matching using DescriptorMatcher. If that's the case, what is FeatureDetection used for?

推荐答案

特征检测

• 在计算机视觉和图像处理中，特征检测的概念是指旨在计算图像信息的抽象并在每个图像点进行局部决策的方法，即该点是否存在给定类型的图像特征或不是.生成的特征将是图像域的子集，通常以孤立点、连续曲线或连接区域的形式出现.

• In computer vision and image processing the concept of feature detection refers to methods that aim at computing abstractions of image information and making local decisions at every image point whether there is an image feature of a given type at that point or not. The resulting features will be subsets of the image domain, often in the form of isolated points, continuous curves or connected regions.

特征检测 = 如何在图像中找到一些有趣的点(特征).(例如找角、找模板等等.)

特征提取

• 在模式识别和图像处理中，特征提取是一种特殊的降维形式.当算法的输入数据太大而无法处理并且被怀疑是众所周知的冗余(大量数据，但信息不多)时，输入数据将被转换为特征的简化表示集(也称为特征向量).将输入数据转换为特征集称为特征提取.如果提取的特征经过仔细选择，则预计特征集将从输入数据中提取相关信息，以便使用这种简化表示而不是全尺寸输入来执行所需的任务.

• In pattern recognition and in image processing, feature extraction is a special form of dimensionality reduction. When the input data to an algorithm is too large to be processed and it is suspected to be notoriously redundant (much data, but not much information) then the input data will be transformed into a reduced representation set of features (also named features vector). Transforming the input data into the set of features is called feature extraction. If the features extracted are carefully chosen it is expected that the features set will extract the relevant information from the input data in order to perform the desired task using this reduced representation instead of the full-size input.

特征提取 = 如何表示我们发现的有趣点，以便将它们与图像中的其他有趣点(特征)进行比较.(例如，该点的局部区域强度​​?该点周围区域的局部方向?等等)

实际例子:你可以用哈里斯角方法找到一个角，但你可以用任何你想要的方法来描述它(例如，Histograms、HOG、Local Orientation in the 8th adjacency)

您可以在这篇维基百科文章中查看更多信息.

You can see here some more information in this Wikipedia article.

这篇关于特征检测和描述符提取有什么区别?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！