Re: [R] Image Classification in R

2013-10-14 Thread Suzen, Mehmet
Hello Lorenzo, Try to locate related R packages from here:
http://cran.r-project.org/web/views/MedicalImaging.html

On 14 October 2013 22:23, Lorenzo Isella  wrote:
> Dear All,
> For a project I am given a set of images. They represent either healthy or
> tumoral tissue, but the specific nature of the images does not matter.
> I need to train a classifier which is expected to tell me in which category
> (let's call it 0 vs 1) each image falls.
> I am thinking about a random forest classifier, but I am uncertain about a
> couple of (fairly important) points
>
> (1) The size of the images varies, so for instance the number of pixels is
> not the same for every image and as a consequence some methodologies (e.g.
> the PCA) when applied to these images will lead to results not immediately
> comparable. Is trying to blur/flatten the images a good idea to have always
> (artificially) the same size (number of pixels) for every image?
> (2) Which features do you recommend to associate\calculate for every image?
> This is what I will use to train my model upon.
>
> Any suggestion is welcome.
> Cheers
>
> Lorenzo
>
> __
> R-help@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

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Re: [R] Image Classification in R

2013-10-14 Thread Bert Gunter
This is an R-help list. These are not questions about R. You should
talk to a local statistical expert instead of posting here.

Cheers,
Bert

On Mon, Oct 14, 2013 at 1:23 PM, Lorenzo Isella
 wrote:
> Dear All,
> For a project I am given a set of images. They represent either healthy or
> tumoral tissue, but the specific nature of the images does not matter.
> I need to train a classifier which is expected to tell me in which category
> (let's call it 0 vs 1) each image falls.
> I am thinking about a random forest classifier, but I am uncertain about a
> couple of (fairly important) points
>
> (1) The size of the images varies, so for instance the number of pixels is
> not the same for every image and as a consequence some methodologies (e.g.
> the PCA) when applied to these images will lead to results not immediately
> comparable. Is trying to blur/flatten the images a good idea to have always
> (artificially) the same size (number of pixels) for every image?
> (2) Which features do you recommend to associate\calculate for every image?
> This is what I will use to train my model upon.
>
> Any suggestion is welcome.
> Cheers
>
> Lorenzo
>
> __
> R-help@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.



-- 

Bert Gunter
Genentech Nonclinical Biostatistics

(650) 467-7374

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R-help@r-project.org mailing list
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.


[R] Image Classification in R

2013-10-14 Thread Lorenzo Isella

Dear All,
For a project I am given a set of images. They represent either healthy or  
tumoral tissue, but the specific nature of the images does not matter.
I need to train a classifier which is expected to tell me in which  
category (let's call it 0 vs 1) each image falls.
I am thinking about a random forest classifier, but I am uncertain about a  
couple of (fairly important) points


(1) The size of the images varies, so for instance the number of pixels is  
not the same for every image and as a consequence some methodologies (e.g.  
the PCA) when applied to these images will lead to results not immediately  
comparable. Is trying to blur/flatten the images a good idea to have  
always (artificially) the same size (number of pixels) for every image?
(2) Which features do you recommend to associate\calculate for every  
image? This is what I will use to train my model upon.


Any suggestion is welcome.
Cheers

Lorenzo

__
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.