Talk:Computer Vision

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Interestingly, biological vision (cats have been extensively studied) seems to have lots of "hardware" assist, that is, special "circuitry" to find lines, etc. However, most computer vision has been done strictly with software.

Removed. This implies that there is a clearly understood, meaningful distinction in neuroscience between hardware and software in the brain. Since this is not the case, I don't see how we can include this.

Also, note that things like the "special 'circuitry' to find lines" have been copied into computer vision efforts; they're called "feature extractors", or some such. --Ryguasu 21:51 Dec 7, 2002 (UTC)

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Much machine vision--which is applied computer vision--takes advantage of specialized hardware to pre-process results. In the 1980s and 1990s it was not uncommon for machine vision equipment manufacturers to develop specialized hardware to perform common operations (esp. connectivity analysis) on incoming video signals. More recently, specialized hardware has been replaced by configurable, programmable boards capable of processing input before the image is presented to a higher level of interface accessible to the programmer or user. -- Rethunk

Contents 1 This article is almost as Machine vision.. 2 Tracking 3 A wrong pointer / copy of this page? 4 Suggestions for improvements of the Computer Vision article and category 5 Introduction 6 Computer vision systems 7 New introduction 8 Scene reconstruction 9 Remove Computer vision laboratories list

[edit] This article is almost as Machine vision..

Should Machine vision and Computer vision combined?

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I removed "Computer vision is a subfield of artificial intelligence and computer graphics." Computer graphics and computer vision have very separate histories, and only within the last 10 years have people started to explore the overlap within the fields. Computer vision arose from artificial intelligence, and was original a sub-topic of one of the main AI conferences (IJCAI, I think). Roughly speaking, computer vision and computer graphics address related, but distinct problems. Computer graphics is about converting scene descriptions to images, and computer vision is about converting images to scene descriptions; one is not a subproblem of the other. In both research and practice, the fields have historically been separate, but this is changing.

I would argue that "machine vision" is a synonym for "computer vision." However the content in the machine vision article is a very limited view of computer vision that focuses on primitive techniques that would not be considered broadly representative of computer vision by any means. -- Aaronh

[edit] Tracking

I removed the "Possible terrorist tracking in the airport" in the examples of tracking tasks. I have never heard of a system which can do this. If someone has a reference to a working system which has solved the terrorist detection, we can put it back in again. KYN 23:41, 12 November 2005 (UTC)

[edit] A wrong pointer / copy of this page?

The people from a company called Riya claim that the computer vision page on wikipedia is completely different from what it actually is... Please check http://www.riya.com/corp/history-face-recongnition.jsp . I think this is not very fair, as this false content is a pure publicity for Riya, which by the way is a very young new comer in the field of face recognition, that does not even test on the FERET db or do the FRVT test.

Should we contact them to correct that? --- They are likely referring to the italicized quote: "Computer vision can be described as the study of methods which can be used for allowing computers to "understand" images, or multidimensional data in general." -varaon

[edit] Suggestions for improvements of the Computer Vision article and category

Please read the suggested improvement posted at The Category:Computer Vision Talk page. --KYN 11:38, 5 February 2006 (UTC)

[edit] Introduction

The introduction to this article seems to be its current weak point. I'm not sure I want to mess with it yet for fear of leaving something out or including my own possible misconceptions or ambiguities, but right now it leaves the reader a bit confused. The first paragraph is fine. The second seems a bit irrelevant at this point in the article; perhaps it should be moved to another section? The third part (point form) should probably be removed; weak grammar aside, it seems useless and redundant. Doze 20:14, 09 May 2006 (UTC)

I agree that the introduction of the article lost clarity when the third paragraph appeard. The second paragraph is not irrelevant but possibly misplaced. Here's my suggestions:

• Delete paragraph 3
• Delete paragraph 2, and write its content into paragraph 4 of state-of-the-art section

--KYN 19:59, 16 May 2006 (UTC)

[edit] Computer vision systems

This section seems a bit unstructured or unorganized. I suggest to replace the content of this section with something more concise like:

The organization of a computer vision system is highly application dependent. Some systems are stand-alone applications which solve a specific measurement or detection problem, while other constitute a sub-system of a larger design which, for example, also contains sub-systems for control of mechanical actuators, planning, information databases, man-machine interfaces, etc. The specific implementation of a computer vision system also depends on if its functionality is pre-specified or if some part of it can be learned or modified during operation. There are, however, typical functions which are found in many computer vision systems.

• Image acquisition: A digital image is produced by one or several image sensor which, besides various types of light-sensitive cameras, includes range sensors, tomography devices, radar, ultra-sonic cameras.
• Pre-processing: Before a computer vision method can be applied to image data in order to extract some specific piece of information, it is usually necessary to process the data in order to assure that it satisfy certain assumptions implied by the method. Examples are
  • Re-sampling in order to assure that the image coordinate system is correct.
  • Noise reduction in order to assure that sensor noise does not introduce false information.
• Feature extraction: Image features at various levels of complexity are extracted from the image data. Typical examples of such features are
  • Lines and edges.
  • Localized interest points such as corners or points.

More complex features may be related to texture, shape or motion.

• Segmentation: At some point in the processing a decision is made about which image points or regions of the image are relevant for further processing. Examples are
  • Selection of a specific set of interest points
  • Segmentation of one or multiple image regions which contain a specific object of interest.
• High-level processing: At this step the input is typically a small set of data, for example a set of points or an image region which is assumed to contain a specific object. The remaining processing deals with, for example,
  • Verification that the data satisfy model-based and application specific assumptions.
  • Estimation of application specific parameters, such as object pose or object size.
  • Classifying a detected object into different categories.

I will change to this content shortly, if there are no major objections. The current content is of course still relevant to computer vision, but is too specific in my opinion. Maybe we can have a separate article or category which in a meaningful way can list various types of processing methods which are frequently appearing in computer vision. --KYN 10:19, 2 August 2006 (UTC)

[edit] New introduction

I would like to suggest the following alternative:

Computer vision is the science of machines that see.

As a scientific discipline, Computer vision is concerned with the theory and technology for building artificial systems that obtain information from images or multi-dimensional data. Information, as defined by Shannon, is that which enables a decision. Since perception can be seen as the extraction of information from sensory signals, computer vision can be seen as the scientific investigation of artificial systems for perception from images or multi-dimensional data.

Examples of applications of ((computer vision systems)) include systems for

1. Controling processes (e. g., an industry robot or an autonomous vehicle).
2. Detecting events (e.g., for visual surveillance for security or commercial services)
3. Organising information (e.g., for indexing data bases of images and sequences),
4. Modeling objects or environments (e.g., industrial inspection, medical image analysis, or topographical modeling),
5. Interaction (e.g., as the input to a device for computer-human interaction).

Computer vision can also be described as the complement (but not necessary the opposite) of biological vision. In biological vision and visual perception real vision systems of humans and various animals are studied, resulting in models of how these systems are implemented in terms of neural processing at various levels. Computer vision, on the other hand, studies and describes artificial vision system which are implemented in software or hardware, in computers or in embedded systems. Interdisciplinary exchange between biological and computer vision has proven increasingly fruitful for both fields.

Subdomains of computer vision include scene reconstruction, event detection, tracking, object recognition, learning, indexing, ego-motion and image restoration.

-JLC

This looks fine to me. What maybe is missing from the current introduction is that computer vision can deal with many types of image sensors, not just standard 2D sensors, and that learning-based systems are becoming useful. The last issue can maybe be worked into the first paragraph of the "State of the art" section and the first one worked into the "Computer vision systems" sections. Also, my spell-checker says "Controling->Controlling", but it has been wrong before... --KYN 14:20, 3 August 2006 (UTC)

Well, one more thing. If you write that computer vision is a science then certain people are inclined to interpret that it is only about research, not about real world applications. --KYN 19:21, 3 August 2006 (UTC)

ok. I agree. I have cleaned up the text, and used American, rather than British spelling.

[edit] Scene reconstruction

I removed the last sentence

"Generally one is interested in finding the fundamental matrix which represents corresponding points from different images. "

from this section. I) The fundamental matrix is a means, not the goal of scene reconstruction. II) I don't believe that this article is a right place to describe the specific methods for solving the scene reconstruction problem. --KYN 17:02, 30 October 2006 (UTC)

[edit] Remove Computer vision laboratories list

There is a list of CV labs at the end of the article. It is a result of a reorganization of the article made about a year ago, where things were moved around rather than deleted, which perhaps they should have. I have noticed that lately a number of new labs have been added to this list and, given time, it could soon be as long as the rest of the article. Furthermore, this list is not, and can probaly never be, a complete list of CV labs. I have tried to find similar "lab lists" in other articles, but so far didn't find any so I guess that this list is rather unique for the CV article. For these reasons I propose to remove the list from the article. --KYN 11:57, 14 November 2006 (UTC)

A better solution might be to create a Computer_vision_labs page with a complete list and more information about each lab like their specific focus and past contributions to the field. --Dougthebug 19:18, 19 January 2007 (UTC)

OK, let's move the list to a "Computer Vision Research Groups" page for a start. However, I reject the idea that the list will ever be "complete", which is one of the reason why I want to remove it from the CV main page. Also, I would be careful to use Wikipedia to duplicate information that is already presented on each group's home page. --KYN 12:45, 30 January 2007 (UTC)

Done! --KYN 20:05, 15 February 2007 (UTC)