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Thread Subject:
feature vector of a image

Subject: feature vector of a image

From: abhishek

Date: 23 Jul, 2009 13:46:27

Message: 1 of 6

hey,
can anyone plzz tell what exactly is feature vector of a image..
how to get this feature vector of the image in matlab
our ma'am has told us to calculate the mean of RGB...wat is dat????
any answer would be appreciated.............

Subject: feature vector of a image

From: arun

Date: 23 Jul, 2009 15:48:17

Message: 2 of 6

On Jul 23, 3:46 pm, abhishek <abhigra...@gmail.com> wrote:
> hey,
> can anyone plzz tell what exactly is feature vector of a image..
> how to get this feature vector of the image in matlab
> our ma'am has told us to calculate the mean of RGB...wat is dat????
> any answer would be appreciated.............

when you load an image in matlab (a colour image) into a variable, it
contains 3 components, (R)ed, (G)reen and (B)lue.

help imread; % this reads the file into a 3D matrix (the 3rd dim
contains R and G and B)

All you have to do is to take the mean of these values of
corresponding indices, from what you say.
best, arun.

Subject: feature vector of a image

From: abhishek

Date: 23 Jul, 2009 17:14:05

Message: 3 of 6

On Jul 23, 8:48 am, arun <aragorn1...@gmail.com> wrote:
> On Jul 23, 3:46 pm, abhishek <abhigra...@gmail.com> wrote:
>
> > hey,
> > can anyone plzz tell what exactly is feature vector of a image..
> > how to get this feature vector of the image in matlab
> > our ma'am has told us to calculate the mean of RGB...wat is dat????
> > any answer would be appreciated.............
>
> when you load an image in matlab (a colour image) into a variable, it
> contains 3 components, (R)ed, (G)reen and (B)lue.
>
> help imread; % this reads the file into a 3Dmatrix(the 3rd dim
> contains R and G and B)
>
> All you have to do is to take the mean of these values of
> corresponding indices, from what you say.
> best, arun.

thank u very much for the information provided......
Our ma'am has also said us to retreive the feature vector of the
image.....
can u plzz give me some idea abt feature vector

Subject: feature vector of a image

From: ImageAnalyst

Date: 23 Jul, 2009 22:55:04

Message: 4 of 6

On Jul 23, 1:14 pm, abhishek <abhigra...@gmail.com> wrote:
> On Jul 23, 8:48 am, arun <aragorn1...@gmail.com> wrote:
>
>
>
>
>
> > On Jul 23, 3:46 pm, abhishek <abhigra...@gmail.com> wrote:
>
> > > hey,
> > > can anyone plzz tell what exactly is feature vector of a image..
> > > how to get this feature vector of the image in matlab
> > > our ma'am has told us to calculate the mean of RGB...wat is dat????
> > > any answer would be appreciated.............
>
> > when you load an image in matlab (a colour image) into a variable, it
> > contains 3 components, (R)ed, (G)reen and (B)lue.
>
> > help imread; % this reads the file into a 3Dmatrix(the 3rd dim
> > contains R and G and B)
>
> > All you have to do is to take the mean of these values of
> > corresponding indices, from what you say.
> > best, arun.
>
> thank u very much for the information provided......
> Our ma'am has also said us to retreive the feature vector of the
> image.....
> can u plzz give me some idea abt feature vector- Hide quoted text -
>
> - Show quoted text -

----------------------------------------------------------------------------------
There is no one, single feature vector for all images. You need to
define your list of features that YOU want for your particular set of
images. This could be mean, std dev, various shape descriptions (such
as circularity, area, perimeter, Euler number, etc.), color, or
whatever you want to measure. You need to define this first. Then
quantify (measure) them using algorithms. Then string all the
numerical measurements together into a single numerical array.
There. That's your feature vector. Now, tell me what features you
want to measure, post an image, and then we can continue.

There's a very, very short terse description here:
http://en.wikipedia.org/wiki/Feature_vector
(someone should expound upon that).
Regards,
ImageAnalyst

Subject: feature vector of a image

From: abhishek

Date: 24 Jul, 2009 10:16:00

Message: 5 of 6

On Jul 23, 10:14 am, abhishek <abhigra...@gmail.com> wrote:
> On Jul 23, 8:48 am, arun <aragorn1...@gmail.com> wrote:
>
> > On Jul 23, 3:46 pm, abhishek <abhigra...@gmail.com> wrote:
>
> > > hey,
> > > can anyone plzz tell what exactly is feature vector of a image..
> > > how to get this feature vector of the image in matlab
> > > our ma'am has told us to calculate the mean of RGB...wat is dat????
> > > any answer would be appreciated.............
>
> > when you load an image in matlab (a colour image) into a variable, it
> > contains 3 components, (R)ed, (G)reen and (B)lue.
>
> > help imread; % this reads the file into a 3Dmatrix(the 3rd dim
> > contains R and G and B)
>
> > All you have to do is to take the mean of these values of
> > corresponding indices, from what you say.
> > best, arun.
>
> thank u very much for the information provided......
> Our ma'am has also said us to retreive the feature vector of the
> image.....
> can u plzz give me some idea abt feature vector

and i understood wat u sed abt the feature vector....
my topic of cbir is
cbir(content based image retreival) using color and textures.....
and ma'am told that each image shud have 424 bits of feature vector
in which ma'am told 8 bits for R, 8 bits for G, and 8 bits of B......
i realised dat v need to define the features for my feature vector....
now my question is which parameters v need for my topic.....
eg..(area , circularity,etc....)
bcuz our ma'am told dat fecture vector shud be of 424
bits...............
out of which i noe 24 bits....i.e mean of RGB
v need to calc mean of R...........(calc mean of entire matrix X(:,:,
1))
v need to calc mean of G...........(calc mean of entire matrix X(:,:,
2))
v need to calc mean of B...........(calc mean of entire matrix X(:,:,
3))
and then putting dis values in feature vector...............
M i right???????????????????????
n plzzz do reply regarding which feactures i go for , for my topic in
feature vector

Subject: feature vector of a image

From: Abhi

Date: 24 Jul, 2009 10:21:02

Message: 6 of 6

ImageAnalyst <imageanalyst@mailinator.com> wrote in message <606c67cf-532c-4dff-a542-9480b9c0d55a@q11g2000yqi.googlegroups.com>...
> On Jul 23, 1:14?pm, abhishek <abhigra...@gmail.com> wrote:
> > On Jul 23, 8:48?am, arun <aragorn1...@gmail.com> wrote:
> >
> >
> >
> >
> >
> > > On Jul 23, 3:46?pm, abhishek <abhigra...@gmail.com> wrote:
> >
> > > > hey,
> > > > can anyone plzz tell what exactly is feature vector of a image..
> > > > how to get this feature vector of the image in matlab
> > > > our ma'am has told us to calculate the mean of RGB...wat is dat????
> > > > any answer would be appreciated.............
> >
> > > when you load an image in matlab (a colour image) into a variable, it
> > > contains 3 components, (R)ed, (G)reen and (B)lue.
> >
> > > help imread; % this reads the file into a 3Dmatrix(the 3rd dim
> > > contains R and G and B)
> >
> > > All you have to do is to take the mean of these values of
> > > corresponding indices, from what you say.
> > > best, arun.
> >
> > thank u very much for the information provided......
> > Our ma'am has also said us to retreive the feature vector of the
> > image.....
> > can u plzz give me some idea abt feature vector- quoted text -
> >
> > - Show quoted text -
>
> ----------------------------------------------------------------------------------
> There is no one, single feature vector for all images. You need to
> define your list of features that YOU want for your particular set of
> images. This could be mean, std dev, various shape descriptions (such
> as circularity, area, perimeter, Euler number, etc.), color, or
> whatever you want to measure. You need to define this first. Then
> quantify (measure) them using algorithms. Then string all the
> numerical measurements together into a single numerical array.
> There. That's your feature vector. Now, tell me what features you
> want to measure, post an image, and then we can continue.
>
> There's a very, very short description here:
> http://en.wikipedia.org/wiki/Feature_vector
> (someone should upon that).
> Regards,
> ImageAnalyst





> On Jul 23, 3:46 pm, abhishek <abhigra...@gmail.com> wrote:

> > hey,
> > can anyone plzz tell what exactly is feature vector of a image..
> > how to get this feature vector of the image in matlab
> > our ma'am has told us to calculate the mean of RGB...wat is dat????
> > any answer would be appreciated.............

> when you load an image in matlab (a colour image) into a variable, it
> contains 3 components, (R)ed, (G)reen and (B)lue.

> help imread; % this reads the file into a 3Dmatrix(the 3rd dim
> contains R and G and B)

> All you have to do is to take the mean of these values of
> corresponding indices, from what you say.
> best, arun.

thank u very much for the information provided......
Our ma'am has also said us to retreive the feature vector of the
image.....
can u plzz give me some idea abt feature vector

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