Mastering OpenCV 4 with Python

Feature detection

A feature can be described as a small patch in the image, which is invariant (as much as possible) to image scaling, rotation, and illumination. This way, the same feature can be detected from different images of the same scene with different perspectives. Therefore, a good feature should be the following:

• Repeatable and precise (the same feature should be extracted from different images of the same object)
• Distinctive to the image (images with different structures will not have this feature)

OpenCV provides many algorithms and techniques to detect features in images. They include the following:

• Harris Corner Detection
• Shi-Tomasi Corner Detection
• Scale Invariant Feature Transform (SIFT)
• Speeded-Up Robust Features (SURF ...