Talk:Blob detection

message: This article does not provide a formal/informal/intuitive definition of what a "blob" really is.  Right now, a blob can be anything which is detected by any of the corresponding methods.  This is of course correct from a practical points of view, but somewhat unsatisfactory from a conceptual/theoretical point of view.  I assume that the inventors of these methods had some idea from the outset about what they wanted to detect before they went ahead and constructed a specific detector.  This mean that there should be an introductory section about what a blob is.
There should also be a section on the applications of blobs.  Otherwise there is no reason for using blob detectors.
If this article is extended in the proposed way, with blob detection as only one aspect, it appears relevant to rename it to "Blob (computer vision)".
--KYN 22:06, 17 September 2006 (UTC)
thread_title:  Requested extensions 

message: I think this article shows a lot of good technical work, mostly done by one editor: Tpl. Thank you for your hard work, Tpl! However, I would like to raise the issue of accessibility. According to Wikipedia:Make technical articles accessible:
* technical articles on wikipedia "should be accessible to the widest possible audience"
and
* "Every reasonable attempt should be made to ensure that material is presented in the most widely accessible manner possible."
Those guidelines suggest several ways to make technical articles more accessible. The ways which I think apply to this article at present include:
* Add a concrete example
** How might one apply the blob detection formulae in a real-world situation?
* Explain formulae
** Most of the formulae lack explanations
* Add a picture
** The only picture in the article is quite small, and not specifically about blob detection.
* Use language similar to what you would use in a conversation
* Use analogies
However, in no way do I wish to "dumb-down" this article in the interest of accessibility. I think a balance can be struck which improves this article's accessibility without reducing its utility to advanced readers.
Some ideas off the top of my head for improving the article:
* Add a longer introductory section (or is a separate Introduction to blob detection warranted?) containing examples
* Add pictures (perhaps animations?) and explanations, especially for the formulae
* Loosen up the language -- right now I think it reads too much like a technical reference
With this in mind, I believe the  template is currently warranted. Hopefully that will attract the right editor for making this article more accessible. Thanks! --fjarlq (talk) 04:21, 19 June 2008 (UTC)
thread_title:  Accessibility 

message: I've implemented the laplacian of gaussian method described on this page and it seems to detect things very nicely, but not at the expected t values. Here is a clickable example (takes a few seconds to run):
http://bubba.net.images.alaska.edu/~bkerin/gmcon_safe/gmcon.cgi?operations=type:load,load_name:blobtest,type:run_model
For single-pixel blobs, the normalized laplacian is most negative at the smallest scale, which makes sense I guess. For 3x3 blobs, t = 1.4 gives the most negative result, and for 8x8 blobs t = 10 gives the most negative result. Does the agorithm respond differently for small blobs or is there something wrong with my implementation?
Bkerin2 (talk) 19:20, 6 May 2009 (UTC)
thread_title:  Does scale work as advertised for small blobs? 

message: Can anyone fix this? The picture doesn't show the red dots.
Template_talk:FeatureDetectionCompVisNavbox
Unapiedra (talk) 08:50, 13 June 2009 (UTC)
thread_title:  Picture broken 

message: I think that 'scale' and 'diffusion time' are mixed up in this article. In the first equation 't' is the scale parameter (the standard deviation for a normal distribution). But i think for the rest of the equations 't' refers to something like the diffusion time (and it seems to follow the original Tony Lindenberg definition) leading to the 'strange' diffusion equation with the constant 1/2 in front).
This could account for the remark where someone explains that he does find extrema but not at the correct scale. Original authors: am i wrong?  —Preceding unsigned comment added by 213.10.57.74 (talk) 19:36, 4 October 2010 (UTC)
thread_title:  Scale versus Diffusion time 

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thread_title:  External links modified 

message: It says r = \sqrt{2}t, and inferring from the formulas   t := \sigma^2.  I have looked in multiple source codes and people use \sigma = r/\sqrt{2}, not \sigma^2 = r/\sqrt{2}, and this seems to give me better results.  Can't find a source on correct \sigma or  t  relationship to r. CyreJ (talk) 11:44, 27 January 2023 (UTC)
replies: text: dimensions t\sim r^2 make more sense for a unitless exponent. Changed on main page.  CyreJ (talk) 11:56, 27 January 2023 (UTC)
thread_title:  Radius - standard deviation relation.  Is it correct?