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face extraction from an image

fida khalid — Sun, 14 Mar 2010 14:45:06 -0400

hello
i want to know how can i extract the face from a given image; when i input an image for the whole body how can i extract the face and just the face and save the extarction information as a new image?
is my quistion clear??

Re: Execution Time

Rune Allnor — Sun, 14 Mar 2010 14:37:47 -0400

On 14 Mar, 15:25, "ASL Bravo" <engr...@live.co.uk> wrote:
> hii,
>
> Does anyone help me to find the execution time of my code(shown below),

doc profile

Rune

Feature Extraction

Yashveer Ramparsad — Sun, 14 Mar 2010 14:35:06 -0400

Doing this number plate recognition thing. And i have the number plate already, and can segment the letters and number from the plate. I've done lots of research and most of the articles say they've used Template Matching. I've seen one that uses SEPCOR, not sure what it is exactly, apart from the fact that it uses statistical methods for matching. There are problems with both methods, what i wanted to know is which would be the better to use, and why. And is there a proper definition for SEPCOR cos google doesn't really provide a proper reference.

Re: Update M File

Jan Simon — Sun, 14 Mar 2010 14:34:05 -0400

Dear Brendan!

> I often will edit a matlab m file on one computer, and copy the file to a machine that is more powerful and has more resources for execution. However, I am having the following incredibly frustrating problem: many times the when I copy over an old version of an m-file with a new version, the code from the old version is run instead. I believe this has to do with the compilation of the m files, i.e. there is some intermediate code file from the old m code (.asv I think) that is being run instead of the new m code. I had been calling the 'rehash' command recently, which seemed to work better (i.e. my new code was run often than before), but I still have cases when the old code is run instead. I have also tried the refresh command with no success.
>
> Does anyone know a resolution to this problem? It is insanely frustrating to run a program that takes one hour, only to find out afterwards it ran the old version of the code.

The .asv files are just backups of the M-files and they are not used for processing. But there are copies of the M-files in the memory. Usually they are replaced if newer versions of the files are available, but this may fail if you work on a network drive and the "change notification handles" of the operating system are exhausted. Fortunately there is a tool which never fails to remove the M-functions from the memory: CLEAR.
Either clear the specific file, e.g. myFunc.m:
clear myFunc
or all functions:
clear functions

Did you try "rehash pathreset" ? I'd expected, that this works well. But I'd rely on CLEAR.

Good luck, Jan

Re: distribution function

Matt J — Sun, 14 Mar 2010 14:34:05 -0400

"jeny hu" <Yoggi@post.sk> wrote in message <hnipei$pn5$1@fred.mathworks.com>...

> > help cumsum
> I need the cdf for statistical testing(kstest,kuiper test....) and i know the result(accept H0) and I've already tried cumsum but this ends with rejecting H0
==============

That doesn't mean cumsum is wrong. It could mean there's aproblem somewhere else.

Re: Matlab Mex Compiler and Csdp.Exe Error

ali — Sun, 14 Mar 2010 14:33:02 -0400

pls somebody help me pls

Execution Time

ASL Bravo — Sun, 14 Mar 2010 14:25:06 -0400

hii,

Does anyone help me to find the execution time of my code(shown below), also m a newbie, any help to modify or make this code compliant to MAAB guideline is appreciated.

function vehiclespeed = Calspeed(WSFrR,WSFrL,WSRrR,WSRrL,FrRQF,FrLQF,RrRQF,RrLQF)
%#eml
% This block supports an embeddable subset of the MATLAB language.
% See the help menu for details.

if FrRQF ==3
     FrR_QF = True;
else FrR_QF = False;
end;

if FrLQF ==3
     FrL_QF = True;
else FrL_QF = False;
end;

if RrRQF==3
     RrR_QF = True;
else RrR_QF = False;
end;

if RrLQF ==3
     RrL_QF = True;
else RrL_QF = False;
end;

if (FrR_QF && FrL_QF && RrR_QF && RrL_QF)
      a = [WSFrR,WSFrL,WSRrR,WSRrL];
      vehiclespeed = Avg(a);

      elseif (FrR_QF && FrL_QF && RrR_QF)
              b = [WSFrR,WSFrL,WSRrR];
              vehiclespeed = Avg(b);
      elseif (FrR_QF && FrL_QF && RrL_QF)
              b = [WSFrR,WSFrL,WSRrL];
              vehiclespeed = Avg(b);
      elseif (FrR_QF && FrL_QF && RrL_QF)
              b = [WSFrR,WSFrL,WSRrL];
              vehiclespeed = Avg(b);
      elseif (FrR_QF && RrR_QF && RrL_QF)
              b = [WSFrR,WSRrR,WSRrL];
              vehiclespeed = Avg(b);

      elseif (FrR_QF && FrL_QF)
              c = [WSFrR,WSFrL];
              vehiclespeed = Avg(c);
      elseif (FrR_QF && RrR_QF)
              c = [WSFrR,WSRrR];
              vehiclespeed = Avg(c);
      elseif (FrR_QF && RrL_QF)
              c = [WSFrR,WSRrL];
              vehiclespeed = Avg(c);
      elseif (FrL_QF && RrR_QF)
              c = [WSFrL,WSRrR];
              vehiclespeed = Avg(c);
      elseif (FrL_QF && RrL_QF)
              c = [WSFrL,WSRrL];
              vehiclespeed = Avg(c);
      elseif (RrR_QF && RrL_QF)
              c = [WSRrR,WSRrL];
              vehiclespeed = Avg(c);

      elseif (FrR_QF)
              vehiclespeed = WSFrR;
      elseif (FrL_QF)
              vehiclespeed = WSFrL;
      elseif (RrR_QF)
              vehiclespeed = WSRrR;
      elseif (RrL_QF)
              vehiclespeed = WSRrL;

      else
              vehiclespeed = 0;
end;

function AvgSpeed = Avg(q)
SpeedAscend = Sort(q);
AvgSpeed = (SpeedAscend(1)+SpeedAscend(2))/2;

Assigning Property to Space Points

Arash — Sun, 14 Mar 2010 14:20:31 -0400

Hi,

I would like to assign scalar property to 3D space points, the problem
is;

1) How does the non uniform property (Pi) store as their related space
points (Xi,Yi,Zi)?
2) How could the property called back by entering its coordinates?
3) Is there any possibility to use some function in this regards?

Thank you very much in advance
Arash

Re: Detect black pixels in an image

ImageAnalyst — Sun, 14 Mar 2010 14:17:22 -0400

Hugh Thompson:
I agree with John in that it seems like your definition of black seems
to change with each image. So you really need some kind of
thresholding algorithm - I assume you want an autothresholding method,
perhaps with some visual verification/acceptance by the user.

image_new = image < hist_thresh/2 should always work as long as you
have a monochrome image. Why doesn't it work? Do you mean is doesn't
"work" because you have chosen a threshold that's not appropriate? If
so, again, you need a good thresholding algorithm. But you should
realize that not every image has a nice flat, uniform background with
contrasty objects sitting on it so a global threshold like you're
doing may not work. What if the objects are on a background that is
like a ramp, or varies wildly depending on where you are in the
image? You may have to do some preprocessing of the image to flatten
the background so you can detect the objects by thresholding. And we
can't make suggestions on that until we see a wide variety of images.
So post some.

And like has been said many times before, if you have control over the
image capture situation, it's far better to get a good image there
than to try fancy algorithms later to try to fix it up.

If you have a color image, John's suggestion of transforming your
color space is a good one. There is a function rgb2hsv() that you can
look into. No such nice and easy function for rgb-to-lab - I don't
know why - but you can do it with the makecform function as described
in this demo on color segmentation:
http://www.mathworks.com/products/image/demos.html?file=/products/demos/shipping/images/ipexfabric.html
Good luck,
ImageAnalyst

Re: Update M File

John D'Errico — Sun, 14 Mar 2010 14:14:04 -0400

"Brendan Klare" <bklare@gmail.com> wrote in message <hnipnu$o7$1@fred.mathworks.com>...
> I often will edit a matlab m file on one computer, and copy the file to a machine that is more powerful and has more resources for execution. However, I am having the following incredibly frustrating problem: many times the when I copy over an old version of an m-file with a new version, the code from the old version is run instead. I believe this has to do with the compilation of the m files, i.e. there is some intermediate code file from the old m code (.asv I think) that is being run instead of the new m code. I had been calling the 'rehash' command recently, which seemed to work better (i.e. my new code was run often than before), but I still have cases when the old code is run instead. I have also tried the refresh command with no success.
>
> Does anyone know a resolution to this problem? It is insanely frustrating to run a program that takes one hour, only to find out afterwards it ran the old version of the code.

Where do you put these files?

Do NOT place them in the MATLAB toolbox directories,
as those files are not seen until MATLAB restarts.

I once wrote a function to sync a set of directories,
downloading only those files that are new. I should
look to see where it is.

John

Re: Image Attacks

ImageAnalyst — Sun, 14 Mar 2010 14:01:26 -0400

Abdulhakeem Othman:
So you already have a watermarked image and you're trying to the
watermark itself?

I don't have a demo on all those filters but they're described in the
help documentation. Here's a more general purpose demo on object
segmentation and measurement:
http://www.mathworks.com/matlabcentral/fileexchange/25157

If you have any more specific questions, come back and post your code
and images. It's always preferable to make image processing
suggestions when you have an image that you can look at.

Re: ask for help expanding a matrix

Yaquan Xu — Sun, 14 Mar 2010 13:59:04 -0400

Thank you so much. It really solved my problem!

"Bruno Luong" <b.luong@fogale.findmycountry> wrote in message <hni4se$ot2$1@fred.mathworks.com>...
> >> A=[0 5 2 3
> 5 0 1 4
> 2 1 0 5
> 3 4 5 0]
>
> A =
>
> 0 5 2 3
> 5 0 1 4
> 2 1 0 5
> 3 4 5 0
>
> >> kron(A,[1 0; 0 1])
>
> ans =
>
> 0 0 5 0 2 0 3 0
> 0 0 0 5 0 2 0 3
> 5 0 0 0 1 0 4 0
> 0 5 0 0 0 1 0 4
> 2 0 1 0 0 0 5 0
> 0 2 0 1 0 0 0 5
> 3 0 4 0 5 0 0 0
> 0 3 0 4 0 5 0 0
>
> % Bruno

Update M File

Brendan Klare — Sun, 14 Mar 2010 13:53:02 -0400

I often will edit a matlab m file on one computer, and copy the file to a machine that is more powerful and has more resources for execution. However, I am having the following incredibly frustrating problem: many times the when I copy over an old version of an m-file with a new version, the code from the old version is run instead. I believe this has to do with the compilation of the m files, i.e. there is some intermediate code file from the old m code (.asv I think) that is being run instead of the new m code. I had been calling the 'rehash' command recently, which seemed to work better (i.e. my new code was run often than before), but I still have cases when the old code is run instead. I have also tried the refresh command with no success.

Does anyone know a resolution to this problem? It is insanely frustrating to run a program that takes one hour, only to find out afterwards it ran the old version of the code.

Re: distribution function

jeny hu — Sun, 14 Mar 2010 13:48:02 -0400

"Matt J " <mattjacREMOVE@THISieee.spam> wrote in message <hniomr$eu4$1@fred.mathworks.com>...
> "jeny hu" <Yoggi@post.sk> wrote in message <hniogl$c6p$1@fred.mathworks.com>...
>
> > the code creates a probability density function and i need to create a distribution function
> ===============
>
> help cumsum
I need the cdf for statistical testing(kstest,kuiper test....) and i know the result(accept H0) and I've already tried cumsum but this ends with rejecting H0

Re: parameter constraint on crossCorr

John D'Errico — Sun, 14 Mar 2010 13:47:03 -0400

"M Ladderman" <mirresimons@gmail.com> wrote in message <hni9q0$6ln$1@fred.mathworks.com>...
> Is this is a stupid question or is the answer not easy. thanks for reading this mssg again, sorry to move it up in this way but I am struggling with it.
>
>
> "M Ladderman" <mirresimons@gmail.com> wrote in message <hndolo$rqf$1@fred.mathworks.com>...
> > dear all,
> >
> > I want to constrain the crossCorr function to return parameters/solutions between 0-1, because a priori I do not expect any negative relationships.
> >
> > Is there an easy way to do this that I am overlooking, thanks.

Rune says it all. Just because you believe something
is true about the correlations does not mean that it
will in fact come out that way.

If wishes were horses, beggars would ride.

If you absolutely want it to happen, and are willing
to "cook the books", then just replace any negative
correlations with zero. Problem solved.

John
John