File talk:Comparison convolution correlation.svg

Convolution = Cross-correlation?

it seeems like the convolution example uses a different triangle shaped window from the top row to the lower rows... can anyone correct it?

The difference is intentional; in convolution, g(t) is horizontally flipped. That's what distinguishes it from cross-correlation. cmɢʟee ☎✉ 23:23, 17 July 2012 (UTC)[reply]

The cross-correlation $f\star g$ is incorrect. According to the definition in the article, it should be reversed, making it look exactly like the convolution (this is consistent with the statement in the Properties section that "If f is Hermitian, then $f\star g=f*g.$ "). It looks like this diagram was made using a different convention from that in the article. --TSchwenn (talk) 23:56, 29 September 2012 (UTC)[reply]

I've done a bit of checking and still think that the graphic is correct.

For convolution, Fig 13-5 in ^[1] has similar f, g and f * g.

I couldn't find proper source for cross-correlation, but this video shows MATLAB giving the same result.

This video summarises the differences. cmɢʟee⎆τaʟκ 01:22, 19 September 2014 (UTC)[reply]

^ Steven W. Smith. "The Scientist and Engineer's Guide to Digital Signal Processing — Chapter 13: Continuous Signal Processing". Retrieved 19 September 2014. {{cite web}}: line feed character in |title= at position 38 (help)

Asymmetric function to illustrate autocorrelation

IMO it would be more informative if some non-symmetric function (for example g function instead of square f) were used tu illustrate autocorrelation. Marioosz (talk) 17:41, 17 January 2013 (UTC)[reply]

Done cmɢʟee⎆τaʟκ 02:03, 19 September 2014 (UTC)[reply]

[1] Steven W. Smith. "The Scientist and Engineer's Guide to Digital Signal Processing — Chapter 13: Continuous Signal Processing". Retrieved 19 September 2014. {{cite web}}: line feed character in |title= at position 38 (help)

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