to move a virtual window

hai

i have a image i have to move a window of height 700 and width 30 over the image continuously from left to right i have used the following code by i can't get the answe

Actually i am having a 605X700 image and a window of size 30X700 first i have to go from 1-30 then 2-31 and 3-32 and 4-33 and so on and the code i have used is below

a=1;
b=30;
for i=1:700
    for j=a:b
        if(b<=700)
            yvalue=sum(fmap1(i,j));
           a=a+1;
           b=b+1;
        end
    end
end
please help me thanks in advance

[Jan]

What do you want to calculate? I assume "fmap1(i,j)" is a scalar value, so why do you apply a SUM?

Answer 1

[Walter Roberson]

Looks to me as if you should be using blockproc() or blkproc()

[ramya raj]

i have already used blkproc() function while using blkproc() i am getting a 1X23 matrix but actually i want a 1X670 around matrix it can be possible only if i use the for loop and the for loop that i have used is mentioned by me above but im not getting the correct answer on sing the for loop there is a small mistake in it but i can't find it

[Walter Roberson]

Sounds like you failed to specify the overlap to blkproc()

Your code is overwriting "yvalue" each time through the loop, so at the end of the loops, yvalue will contain only the result for the very last iteration.

Answer 2

[Jan]

I cannot find out, what you want to calculate. If you want a running mean, this methods solves the problem:

fmap1 = rand(605, 700);
b = 30;
yvalue = zeros(605 - b, 700);
for i = 1:605 - b
  yvalue(i, :) = sum(fmap1(i:i + b - 1, :));
end

This is not efficient, because most of the rows are added repeatedly. But it is as near to your original code as possible. If you want something else, you have the chance to explain it here.

[ramya raj]

actually i have to calculate the sum of pixel values inside a window of size 30X700 for that i have to gradually move the window over the image of size 605X700 first i have to calculate the sum of pixel values for first 1-30pixels second sum for 2-31 pixels and third 3- 32 pixels extra up to 700 pixels

[Jan]

The solution I have posted does what you want, but along the first dimension, while you want it along the 2nd dimension. I think, you are able to convert my example accordingly.