Talk:Feature (computer vision)

message: I find the current introductory definition, "a feature is a piece of information which is relevant for solving the computational task related to a certain application", to be far too broad and vague. This definition covers more or less any piece of information on any topic in any context. For example, the big O complexity of the computational task of sorting a database table is "a piece of information which is relevant for solving the computational task related to a certain application" , but it is obviously not a feature for the purposes of this article.
In my view the introductory definition should contain the following aspects: 1) the term 'feature' (as intended in this article) relates to images and analogous data structures, 2) the term relates to the content of an image, as opposed to meta-data, 3) a feature is typically (though certainly not always) either present or absent, and 4) a feature is typically (though not always) local.
Accordingly I propose to change the introductory definition to: "a feature is a piece of information about the content of an image, typically about whether a certain region of the image has certain properties". This seems to cover the content of the article quite well. However, I don't consider myself to be expert enough in this field to make the change myself. Could anyone else weigh in? Wikiedit738 (talk) 09:54, 12 August 2020 (UTC)
thread_title: Introductory definition of the term 'feature'

message: * This article is tough to read for beginners in the subject, therefore maybe not rewriting but sectionning it. Lincher 04:24, 5 December 2005 (UTC)
thread_title: expert tag

message: From my viewpoint this article is too abstract. Although I count myself as an expert in the field, I have problems to find the article informative. From my viewpoint, the article appears to give  a very specific and narrow viewpoint to the notion of features. Moreover, the reference list is too unbalanced. Tpl 12:26, 18 September 2006 (UTC)
thread_title:  Other tags needed as well 

message: Another aspect that needs to be discussed is the distinction between feature detection and feature extraction or feature estimation.  I my view, detection implies a classification process: either the feature is there or not.  A feature detector gives you the answer yes or no.  Some features however, a more complex and call for a more sophisticated representation than a boolean variable.  For example, line/edge features can be described in terms of their orientation, phase and certainty of presence.  This information can conveniently be encoded into a matrix or tensor such as the structure tensor.  Personally, I would not refer to the process of computing such a description as "detection", but rather as "estimation" or possibly as "extraction".  On the other hand, if we use a Canny approach, we get a boolean statement in each pixel about edge presence, hence "detection" is appropriate.
:I agree that the detectors described under edge detection, corner detection, blob detection and ridge detection imply that local decisions are made whether a feature of a certain type exists at a certain image point. This is the meaning of "detection" and with this additional motivation I insist that "detection" should be kept in the naming of these articles. I do also agree that there are other approaches to computing features, for example in terms of non-binary (scalar or vector-valued) feature maps. The second-moment matrix / structure tensor is an example of such a descriptor. At your home page at Wikipedia, I saw that you are working on an article on the structure tensor. If you release this article, others could complement. Nevertheless, I would find it better to describe feature map approaches in another article (or several other articles) than the feature detection articles. As the feature detection articles are now, they are quite well developed and describe state-of-the-art approaches. I think that it is better to have focused articles that give good and updated descriptions of well-defined topics than general articles that aim at too much and will remain incomplete relative to the claims. I you would like an overview article on these notions, I think that feature map would be a reasonable name. This article could then refer to the article on the structure tensor. From such a viewpoint it would also be better to rename the current article Feature (computer vision) into feature detection provided that current forward reference from feature detection is removed. Tpl 15:59, 20 September 2006 (UTC)
replies: text: To avoid the problem with different viewpoints on what should be meant by a feature, I have moved the specific material on precisely feature detection to a specific article on this topic. In the article on Feature (Computer vision), I have replace the corresponding material by a reference to that article. In this way, I think that we solve the problem of "detection" and you can continue to develop the notion of "feature maps". Tpl 16:32, 20 September 2006 (UTC)
thread_title:  Detection, estimation and extraction