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Re: [WM]: Query [Negetive Frequency]
Hi Siju,
I think negative values indicate a phase reversal of 180 degrees, since DCT coefficients represent cosine functions of varying
frequency. In spatial terms, a phase reversal of a particluar frequency component of an existing image would mean that the darkest
areas at that frequency would turn brightest and vice versa.
A simple way to understand this better is to take an image, obtain its DCT and then change certain coefficients to their negative
and then take the inverse DCT to see what effect it has on the image.
Adarsh
On Apr 11, 2005 4:36 AM, Siju Joseph <sigu_joseph@yahoo.co.uk> wrote:
> Hi to all,
> When I am finding the DCT of a image, I am getting negetive values,
> What does this negetive frequency represent?? I mean the real physical meaning..
> Could anyone pls help me
> Thanks in advance
>
> Regards,
>
> Siju Joseph
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