Smooth in time and space?

[vlad59]

Originally posted by bb
@vlad59:
I would like to test the Convolution3D with standard and full-1 matrix at the same time; this way it's easier to compare.
BTW: What do you say about the possibility of optimizing the algorithm for a full-1 matrix (in fact you wouldn't need a matrix at all in this special case)?

bb

I don't fully understand, what I'll do is to provide a new Convolution wich has a new parameter to choose between the two matrix.
I hope that's what you want

Optimizing for the full 1 matrix is not easy, let's take an example :

Tresholded matrix are : 
10 11 11     13 15 5     10 11 11     
10 11 11     13 15 5     10 11 11     
10 11 11     13 15 5     10 11 11     

To find my new convoluted values I've to add all the matrix values :
Sum = 10 + 11 + 11 + 13 + 15 + 5 + .........

And then divide by the numbers of matrix value i.e. 9+9+9 = 27

new values = sum / 27

That division is the problem :
 - I have no MMX opcode to perform a division (or I missed something)
 - and a simple division will be way too slow.

That's why I first tried having a weight matrix like that : 
1 1 1    1 1 1    1 1 1  
1 2 1    2 2 2    1 2 1
1 1 1    1 1 1    1 1 1

With this I can use a left shift to divide by 32
But with this the compressibility test is worse than with the standard matrix

So if anybody has an idea ....
I have got no time to think about it this weekend, thursday is off in France so you can expect a release in 2 or 3 days max.