problem of applying block processing function

my image is gray scale image of 100*120. my programme is

*fun=@(x) x.*2;
B = blkproc(I,[4 4],[1 1],fun);*

when i'm looking for 1st sub block it gives only a single number, it equals to the twice of (1,1) pixel value of original image. can't i get the twice of 1st 4*4 block.is it possible or not.

Answer 1

[Image Analyst]

It gives a single number but you can multiply by ones(blockSize) to expand it. See the attached demos scripts.

[mahesh chathuranga]

can you please edit my codes.thanks.

[mahesh chathuranga]

my 1st sub block is[1 12 3 5;34 78 9 4;1 2 3 4;5 6 7 8]; when i'm run my programme,it gives only 2 for the out put of B(1,1).but i want to get this[2 24 6 10;68 156 18 8;2 4 6 8;10 12 14 16].how can i get this.

[Image Analyst]

I don't know what you're doing. You didn't attach your code. Can't you figure it out from the two examples I gave you? No need to accept an answer until your problem is solved.

[mahesh chathuranga]

sorry.i dont know how to figure out this.

[Image Analyst]

Figure what? Figure out how to download and run the two well-commented examples I included? Just click on the filenames, type control-a, control-c, go to an empty/new editor window in MATLAB, and type control-v, then click the green triangle. Go here for more help http://www.mathworks.com/matlabcentral/answers/8026-best-way-s-to-master-matlab

[mahesh chathuranga]

It gives the error message ??? Undefined function or method 'blockproc' for input arguments of type 'function_handle'.

Error in ==> Untitled at 44 blockyImage8 = blockproc(single(grayImage), blockSize, medianFilterFunction);

[Image Analyst]

You must have a really, really old version of MATLAB. It had a different name back then, something like blkproc, blkprc, or something like that. You need to find out what it's called in your ancient version of MATLAB. Or just upgrade.

[mahesh chathuranga]

I,m working with R2009a,it uses blkproc. but is there any method in matlab to find the old codes.