Thread Subject: slide 3x3 box over image to read values

I want to slide a 3x3 box over the image to read the values in that
3x3 box , Any ideas please ?

Your description was vague, but I think you might want
something like a convolution of your image with a 3x3 of
ones. If so, use the function conv2.

%A = your image
B = ones(3,3);
C = conv(A,B,'same');

fas <faisalmufti@gmail.com> wrote in message
<7ec8e451-c6db-4bf1-9ed0-a5e6d39a4f8f@a9g2000prl.googlegroups.com>...
> I want to slide a 3x3 box over the image to read the
values in that
> 3x3 box , Any ideas please ?

On May 8, 4:18=A0pm, fas <faisalmu...@gmail.com> wrote:
> I want to slide a 3x3 box over the image to read the values in that
> 3x3 box , Any ideas please ?

imtool?

On May 8, 2:35 pm, Richard Brown <rgbr...@gmail.com> wrote:
> On May 8, 4:18 pm, fas <faisalmu...@gmail.com> wrote:
>
> > I want to slide a 3x3 box over the image to read the values in that
> > 3x3 box , Any ideas please ?
>
> imtool?

No I do not want to do convolution. I want to read the values of a A
matrix( not image to be precise) in a 3x3 window
e.g
A=rand(10,10);
data{1}=A(1:3,1:3);
next time I want to read
data{2}=A(1:3,2:4);
and so on till all the matrix has been read

On May 7, 10:43 pm, fas <faisalmu...@gmail.com> wrote:
> On May 8, 2:35 pm, Richard Brown <rgbr...@gmail.com> wrote:
>
> > On May 8, 4:18 pm, fas <faisalmu...@gmail.com> wrote:
>
> > > I want to slide a 3x3 box over the image to read the values in that
> > > 3x3 box , Any ideas please ?
>
> > imtool?
>
> No I do not want to do convolution. I want to read the values of a A
> matrix( not image to be precise) in a 3x3 window
> e.g
> A=rand(10,10);
> data{1}=A(1:3,1:3);
> next time I want to read
> data{2}=A(1:3,2:4);
> and so on till all the matrix has been read

Unless I'm mistaken in what you're looking for, check the
documentation for blkproc.

On May 8, 9:34 am, Steve Carano <scara...@earthlink.net> wrote:
> On May 7, 10:43 pm, fas <faisalmu...@gmail.com> wrote:
>
>
>
> > On May 8, 2:35 pm, Richard Brown <rgbr...@gmail.com> wrote:
>
> > > On May 8, 4:18 pm, fas <faisalmu...@gmail.com> wrote:
>
> > > > I want to slide a 3x3 box over the image to read the values in that
> > > > 3x3 box , Any ideas please ?
>
> > > imtool?
>
> > No I do not want to do convolution. I want to read the values of a A
> > matrix( not image to be precise) in a 3x3 window
> > e.g
> > A=rand(10,10);
> > data{1}=A(1:3,1:3);
> > next time I want to read
> > data{2}=A(1:3,2:4);
> > and so on till all the matrix has been read
>
> Unless I'm mistaken in what you're looking for, check the
> documentation for blkproc.

Whoops..... blkproc didn't overlap. I meant to suggest nlfilter.

Steve Carano <scarano1@earthlink.net> wrote in message
<b9b035be-4a10-4a65-abb0-
d2bd3e0ed116@x41g2000hsb.googlegroups.com>...
> On May 8, 9:34 am, Steve Carano <scara...@earthlink.net>
wrote:
> > Unless I'm mistaken in what you're looking for, check
the
> > documentation for blkproc.
>
> Whoops..... blkproc didn't overlap. I meant to suggest
nlfilter.

I am running from memory, but I thought that blkproc could
be configured with a specified overlap using optional
parameters when it is called.

I don't have the IP-Toolbox on this machine so I guess you
will need to check the documentation.

Regards

Dave Robinson

On May 9, 2:42 am, "Dave Robinson" <dave.robin...@somewhere.biz>
wrote:
> Steve Carano <scara...@earthlink.net> wrote in message
>
> <b9b035be-4a10-4a65-abb0-
> d2bd3e0ed...@x41g2000hsb.googlegroups.com>...> On May 8, 9:34 am, Steve Carano <scara...@earthlink.net>
> wrote:
> > > Unless I'm mistaken in what you're looking for, check
> the
> > > documentation for blkproc.
>
> > Whoops..... blkproc didn't overlap. I meant to suggest
>
> nlfilter.
>
> I am running from memory, but I thought that blkproc could
> be configured with a specified overlap using optional
> parameters when it is called.
>
> I don't have the IP-Toolbox on this machine so I guess you
> will need to check the documentation.
>
> Regards
>
> Dave Robinson

The problem is that I do not want to apply any operation. What I want
is just to read the values of a 2D matrix( may not be an image) as a
3x3 window slides over the complete matrix. It is like putting a frame
of 3x3 on matrix and slide it and read what ever is there in that 3x3
frame overlapping the matrix. What I do with the values that I get is
a separate issue. Any ideas now ?

On May 8, 12:43=A0am, fas <faisalmu...@gmail.com> wrote:
> On May 8, 2:35 pm, Richard Brown <rgbr...@gmail.com> wrote:
>
> > On May 8, 4:18 pm, fas <faisalmu...@gmail.com> wrote:
>
> > > I want to slide a 3x3 box over the image to read the values in that
> > > 3x3 box , Any ideas please ?
>
> > imtool?
>
> No I do not want to do convolution. I want to read the values of a A
> matrix( not image to be precise) in a 3x3 window
> e.g
> A=3Drand(10,10);
> data{1}=3DA(1:3,1:3);
> next time I want to read
> data{2}=3DA(1:3,2:4);
> and so on till all the matrix has been read

------------------------------------
fas:
Then just do basically that. Put your code into the callback of a
mousemove of the axes containing your image. Get the x,y coordinate
and extract the 9 values like you say but centered on the x,y
coordinate. Then send the 9 values to a label or table on your GUI or
just send them to the command window. You need to make sure you don't
go outside the image, but otherwise it should be pretty easy to
write. Not sure why you're adding them to a cell array though. If
you want to make sure you hit every pixel in the image, then instead
of hooking it up to the mouse movement, just put in a nested pair of
for loops where you iterate over every line and column until you've
visited every pixel. Again, very easy to write. If you were asking
if there were any canned function that did that, no, I don't know of
any, but you could write your own in about 5 minutes.
ImageAnalyst

On May 9, 10:59 am, ImageAnalyst <imageanal...@mailinator.com> wrote:
> On May 8, 12:43 am, fas <faisalmu...@gmail.com> wrote:
>
>
>
> > On May 8, 2:35 pm, Richard Brown <rgbr...@gmail.com> wrote:
>
> > > On May 8, 4:18 pm, fas <faisalmu...@gmail.com> wrote:
>
> > > > I want to slide a 3x3 box over the image to read the values in that
> > > > 3x3 box , Any ideas please ?
>
> > > imtool?
>
> > No I do not want to do convolution. I want to read the values of a A
> > matrix( not image to be precise) in a 3x3 window
> > e.g
> > A=rand(10,10);
> > data{1}=A(1:3,1:3);
> > next time I want to read
> > data{2}=A(1:3,2:4);
> > and so on till all the matrix has been read
>
> ------------------------------------
> fas:
> Then just do basically that. Put your code into the callback of a
> mousemove of the axes containing your image. Get the x,y coordinate
> and extract the 9 values like you say but centered on the x,y
> coordinate. Then send the 9 values to a label or table on your GUI or
> just send them to the command window. You need to make sure you don't
> go outside the image, but otherwise it should be pretty easy to
> write. Not sure why you're adding them to a cell array though. If
> you want to make sure you hit every pixel in the image, then instead
> of hooking it up to the mouse movement, just put in a nested pair of
> for loops where you iterate over every line and column until you've
> visited every pixel. Again, very easy to write. If you were asking
> if there were any canned function that did that, no, I don't know of
> any, but you could write your own in about 5 minutes.
> ImageAnalyst

I think I should rephrase my question. I want to read a 64x48 size
matrix in a block of 5x5. Like first block should have a value of
(1:5,1:5), then (6:10,6:10)... so on

On May 9, 10:59 am, ImageAnalyst <imageanal...@mailinator.com> wrote:
> On May 8, 12:43 am, fas <faisalmu...@gmail.com> wrote:
>
>
>
> > On May 8, 2:35 pm, Richard Brown <rgbr...@gmail.com> wrote:
>
> > > On May 8, 4:18 pm, fas <faisalmu...@gmail.com> wrote:
>
> > > > I want to slide a 3x3 box over the image to read the values in that
> > > > 3x3 box , Any ideas please ?
>
> > > imtool?
>
> > No I do not want to do convolution. I want to read the values of a A
> > matrix( not image to be precise) in a 3x3 window
> > e.g
> > A=rand(10,10);
> > data{1}=A(1:3,1:3);
> > next time I want to read
> > data{2}=A(1:3,2:4);
> > and so on till all the matrix has been read
>
> ------------------------------------
> fas:
> Then just do basically that. Put your code into the callback of a
> mousemove of the axes containing your image. Get the x,y coordinate
> and extract the 9 values like you say but centered on the x,y
> coordinate. Then send the 9 values to a label or table on your GUI or
> just send them to the command window. You need to make sure you don't
> go outside the image, but otherwise it should be pretty easy to
> write. Not sure why you're adding them to a cell array though. If
> you want to make sure you hit every pixel in the image, then instead
> of hooking it up to the mouse movement, just put in a nested pair of
> for loops where you iterate over every line and column until you've
> visited every pixel. Again, very easy to write. If you were asking
> if there were any canned function that did that, no, I don't know of
> any, but you could write your own in about 5 minutes.
> ImageAnalyst

I got it its im2col!