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Anonymous
Not applicable
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Using VPSS down scale 720p50 to 576i25 then video fuzzy

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Hi,
I am using the VPSS down scale 1280x720p50 to 720x576i25. Using the Bicubic algorithm and scaler only mode. The output video was fuzzy.
 
HDMI Reciver Subsystem(1280x720p50 native stream) -> Video In to AXI4-Stream -> VPSS(scale down to 720x576i25) -> AXI4-Stream to Video output -> screen.
 
The following picture showed the 576i25 video difference between Not use VPSS and using VPSS down scale 720p50 to 576i25.
clipboard.jpg
 
Do I have any way to make the video better?
 
 
Thanks for your help.

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Moderator
Moderator
776 Views
Registered: ‎10-04-2017

Hi @Anonymous,

 

As @avcon_lee mentioned, it is unavoidable to lose some information. That is the nature of scaling. 

 

I see that you are using the Bicubic algorithm, have you tried Polyphase? You can customize the algorithm to suit your needs when using Polyphase.

 

From PG231:

"The polyphase concept is explained in Polyphase Scaling. The picture quality (and
resource usage) of a polyphase scaler depends largely on the number of filter taps used
and number of filter phases used. Polyphase scaling offers the highest quality but also
has the highest resource utilization."

 

Also, if our VPSS does not offer an algorithm that works for your needs, there are alternative solutions available from our partners.https://www.xilinx.com/products/intellectual-property/1-pcoqgn.html

 

Regards,

Sam

Don't forget to reply, kudo, and accept as solution.

Xilinx Video Design Hub

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2 Replies
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Explorer
Explorer
820 Views
Registered: ‎07-17-2014

@Anonymous

It is unavoidable to lose some information when video images are shrunk.
Especially for words, there is no good way.

Highlighted
Moderator
Moderator
777 Views
Registered: ‎10-04-2017

Hi @Anonymous,

 

As @avcon_lee mentioned, it is unavoidable to lose some information. That is the nature of scaling. 

 

I see that you are using the Bicubic algorithm, have you tried Polyphase? You can customize the algorithm to suit your needs when using Polyphase.

 

From PG231:

"The polyphase concept is explained in Polyphase Scaling. The picture quality (and
resource usage) of a polyphase scaler depends largely on the number of filter taps used
and number of filter phases used. Polyphase scaling offers the highest quality but also
has the highest resource utilization."

 

Also, if our VPSS does not offer an algorithm that works for your needs, there are alternative solutions available from our partners.https://www.xilinx.com/products/intellectual-property/1-pcoqgn.html

 

Regards,

Sam

Don't forget to reply, kudo, and accept as solution.

Xilinx Video Design Hub

View solution in original post