[Mp4-tech] Why only low frequeny is considered in DCT?

[kaustubh.patankar vsnl.net]

Hi 
The low frequencey components in an image are used becuase of the HVS. (Human Visual System) The high frequency components are noise for the human eye and can be filtered out.
regards
Kaustubh
----- Original Message -----
From: prabhakar <prabhakar.pasunuti gdatech.co.in>
Date: Thursday, November 23, 2023 8:47 pm
Subject: Re: [Mp4-tech] Why only low frequeny is considered in DCT?
To: sagar <sagar sarayusoftech.com>, mp4-tech lists.mpegif.org
> It is possible to reconstruct an approximate copy of the block 
> from the low frequency coefficients. Adding more coefficients 
> produces more accurate reconstruction of the original block.
> 
> Thanks & Regards
> ---------------------------------
> P. Prabhakar
> Digital Video Group
> GDA Technologies Ltd 
> 32 & 46 North Phase 
> Thiru Ve Ka Industrial Estate 
> Ekkatuthangal 
> Chennai - 600 097 India 
> Email: prabhakar.pasunuti gdatech.co.in
> Mobile: 09840517282
> Office : 044-30613429
> 
> 
>  ----- Original Message ----- 
>  From: sagar 
>  To: mp4-tech lists.mpegif.org 
>  Sent: Thursday, November 23, 2023 10:56 AM
>  Subject: [Mp4-tech] Why only low frequeny is considered in DCT?
> 
> 
>  Hi Xperts,
> 
>  I wanted to know when we do DCT ( video preocessing), we only 
> consider the Low frequency elements. Why? 
>  DCT is used for taking out spatial reduncies, and DCT is 
> basically used to decorrelate energy in the image.
>  And other fact being low frequency contains high energy, 
> 
>  If anybody could answer my question, i would be thankful.
> 
>  Warm Regards,
>  Sagar
> 
> 
>    -----Original Message-----
>    From: mp4-tech-bounces lists.mpegif.org [mailto:mp4-tech-
> bounces lists.mpegif.org]On Behalf Of Luo Daniel
>    Sent: Wednesday, November 22, 2023 8:26 PM
>    To: mp4-tech lists.mpegif.org
>    Cc: Luo Daniel
>    Subject: [Mp4-tech] Transport stream analyer
> 
> 
>    Dear all,
> 
>     
> 
>    Do you know if there is any free software TS analyzer that can 
> perform buffer verification?
> 
>     
> 
>    Thanks!
> 
>    Jiancong Luo
> 
>     
> 
> 
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