How to eleiminate the black background and retain the region of interest in my image?

Hai,I have an image of the fist which is captured with a black background.The image is an IR (infra red) image captured with a webcamera converted to work in IR .The picture has captured the veins under the skin.What i want to do is just retain the fist and get rid of the surrounding black area.As in my region of interest is just the fist.How do i do this ? I have done something but am just getting a black image for this:

a=imread('1.jpg');
figure;
imshow(a);
b=rgb2gray(a);
figure;
imshow(b);
[j,k]=size(b);
for g=1:j
    for f=1:k
     if b(j,k)>0.06
      c(j,k)=0;
     else    
         c(j,k)=1;
     end
 end 
end 
figure,imshow(c);

this is the image: http://lastqueen21.blogspot.com/2011/04/image.html Can somebody please tell me the code for what I want ?? Thank you so much :(

Answer 1

[Sean de Wolski]

I would do this using my shrinkWrap function:

I = imread('answers421.jpg'); %answers421.jpg is your image
M = shrinkWrap(rgb2gray(I)); %map of hand
IjustHand = bsxfun(@times,uint8(M),I); %apply map to rgb image
imshow(IjustHand) %view

shrinkWrap is available here: FEX shrinkWrap

EDIT to show result:

Answer 2

[Khadeejah]

<<
a=imread('1.jpg'); 
figure; imshow(a); 
b=rgb2gray(a); 
figure; imshow(b); 
[j,k]=size(b); 
for g=1:j
for f=1:k 
if b(j,k)>0.06 
c(j,k)=0; 
else c(j,k)=1; 
end 
end 
end 
figure,imshow(c);
>>

[Sean de Wolski]

<<url_to_a_web_address_with_your_image>>

www.uploadhouse.com is a good free uploading site that allows for direct links.

[Khadeejah]

hai sean ..can u see i ve edited the main question ...bt ill put it here as well :

<<http://lastqueen21.blogspot.com/2011/04/image.html>>

Answer 3

[Khadeejah]

is this right the way I ve put it ?

[Sean de Wolski]

Yes.

Answer 4

[Khadeejah]

hai sean ...! :D thnaks for your answer . I have downloaded this m file .Am very new to this ..so after downloading, I extract it and do what ? ASin should i store it in a folder in matlab ? which 1 ?

Answer 5

[Khadeejah]

i downloaded the file and saved it in work folder and did this program that u mentioned. a=imread('1.jpg'); figure(1); imshow(a); b=shrinkWrap(rgb2gray(a)); IjustHand=bsxfun(@times,uint8(M),a); imshow(IjustHand); >

this is the error am getting, : Error in ==> test at 4 b=shrinkWrap(rgb2gray(a));

So what do i do now :( ?

Answer 6

[Khadeejah]

i did the set path and installed the file . And did the code u mentioned This is the error am getting:

??? Error: File: C:\shrinkWrap\shrinkWrap.m Line: 89 Column: 5 Illegal use of reserved keyword "else".

Error in ==> test at 5 c=shrinkWrap(b);

[Sean de Wolski]

What version of ML do you have? Did you change ANYTHING when you downloaded it? It's in working form, to the best of my knowledge, and others have used it so I'm guessing there's something quirky with how you downloaded it.