1. A method for processing an image, comprising: identifying a first group of keypoints in the image; for each keypoint of the first group: a) identifying at least one corresponding keypoint local feature related to said each keypoint; b) for said at least one keypoint local feature, calculating a corresponding local feature relevance probability; c) calculating a keypoint relevance probability based on the local feature relevance probabilities of said at least one local feature; selecting keypoints, among the keypoints of the first group, having the highest keypoint relevance probabilities to form a second group of keypoints, and exploiting the keypoints of the second group for analysing the image, wherein: the local feature relevance probability calculated for a local feature of a keypoint is obtained by comparing the value assumed by said local feature with a corresponding reference statistical distribution of values of said local feature.