Talk:Image moments

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This article needs a more general introductory section to give better context to the layman.--Hooperbloob 05:11, 12 August 2005 (UTC)

It would be nice also to have a history section about how moments were discovered to have uses in computer vision and also how they have been used in practice (eg OCR etc).--AlexSpurling 23:16, 24 May 2006 (UTC)

Contents

[edit] Raw Moments - unreferenced/plagiarism/fair use?

I just read the first paragraph, word-for-word, of the Raw Moments section out of the popular book "Digital Image Processing, Second Edition" by Rafael C. Gonzalez - pg 672-673. I'm not sure on the legalities but should this not at least be referenced? Yani 03:05, 20 November 2006 (UTC)

Word for word? That would indeed be an astonishing coincidence, as I made some small tweaks to the first paragraph a couple of months ago, without ever having read Gonzalez, making the changes for readability, accuracy, and logical flow. But I've heard great minds think alike [smile]. That said, if you think that book is a good reference for this page, by all means add it. I don't have access to it now, but I you think there are fair use issues, why don't you quote the relevant parts here on the talk page and we can deal with what to do next. Baccyak4H (talk) 03:28, 20 November 2006 (UTC)
I'm not going to quote the relevant parts simply because I'd be retyping the whole section! I agree this is astonishing ...but it is unbelievable that such a large correspondence is a coincidence. The only other explanations are that either the book copied Wikipedia, or both have been copied some third party source. Yani 14:38, 12 December 2006 (UTC)

[edit] Covariance matrix

I changed the definition of the covariance matrix because the multiple use of μ was confusing. I also added a clue how the matrix elements are calculated (according to the covariance matrix definition).

[edit] Streamlining and background info

I reorganized the article to make its style more consistent throughout, and showed more explicitly its outliine structure both in sectioning and language. I kept pretty much all the previous material, just moved it around a bit and reworded / elaborated slightly. And I added a little more explanatory material in the intro per Hooperbloob's good request.

I am considering writing an article on moment invariants which would apply to moments in general (e.g., physics) and cover the translation, scale, and rotation types, as well as (possibly) invariance to certain well-defined types of "blurring" (useful for image processing obviously). It would also describe analogs in 3D and perhaps 1D, and it would hopefully update 2D rotation invariant moments to sets which are superior to Hu's in some ways. If I did this, I may move some of this material to that article. Any comments? Baccyak4H 03:38, 19 August 2006 (UTC)

[edit] Orientation angle formula

Could someone please check the formula for the orientation angle, obtained from the covariance matrix ? I implemented this formula and it yielded partially incoherent results. I instead used the formula on this page (3rd slide), worked fine. But I don't want to change the original page if it's correct.Mr Bam (talk) 10:21, 16 January 2008 (UTC)