[Bf-committers] Re: Re: Re: Vectorial Motion Blur

GSR - FR famrom at infernal-iceberg.com
Sun Feb 13 18:15:43 CET 2005


http://www.netmeister.org/news/learn2quote.html

Hi,
fred at mentalwarp.com (2005-02-13 at 1739.34 +0100):
> A=zeros(255,255); %base image
> %Add Black square
> BlockSize=10;
> BlockPosX=10;
> BlockPosY=10;
> for i=BlockPosX:(BlockPosX+BlockSize)
>     for j=BlockPosY:(BlockPosY+BlockSize)
>         A(i,j)=1; % set pixels in the square =1
>     end
> end
> B=zeros(255,255); % the motion blurred image
> 
> for i=5:250 % from 5 to 250 because the blur needs a margin.
>     for j=5:250
>         B(i,j)=( A(i,j)+A(i+1,j+1)+A(i+2,j+2)+A(i-1,j-1)+A(i-2,j-2) ) 
> /5; % computes the blur on a 5pixels length with a -45° direction
>     end
> end

Your code uses the same motion vector for all pixels. Now try what I
said: one pixel with motion, the rest without. Not everything with the
same motion vector, as your code does.

Say dot 100,100 is the one moving, colour 0 in all channels (black),
while the rest are 255 (white). Your code will make 100,100 be (255 +
255 + 0 + 255 + 255) / 5 = 204, dirty white. But the others will be
255, cos the formula for them, due their "non moving vector" has to be
B(i,j)=A(i,j).

GSR
 
-- 
Other day I should run tac in the text lines, TOFU mail at the line
level. Or just paste random text all over the reply, for more fun.
 


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