Image Processing ( calculate perimeter)

How do I now calculate the perimter of this hand . I've got the left image using bmarea and the one on the right is when imclose is used

How do I now find the perimeter as shown on the left? I've got the outline what should i do now ?

http://www.flickr.com/photos/60171113@N05/5602943214/

thank u

Answer 1

[Teja Muppirala]

Use the REGIONPROPS function.

I = peaks(500) > 3;
imshow(I);

P = regionprops(I,'perimeter');
P.Perimeter

[Prashan]

when i ran the function you provided i get the following ouput .how do i give a variable i hve declared so i can find the peak values of that particular image . my imge is in a variable known as BWAREA now i need the peak values as you suggested above of this image. when iran your code i recieved the following output http://www.flickr.com/photos/60171113@N05/5608749401/

[Teja Muppirala]

Sorry.

"peaks" has absolutely nothing to do with finding peaks in an image. "peaks" is just a test function that I (unfortunately) used to make a test image.

What I meant was, use:

regionprops( ??? ,'perimeter')

where ??? is whatever the variable name of your image is.

[Prashan]

when i run that i got the following as an output which i dnt think i s appropriate Perimeter: 1.3613e+004

[Sean de Wolski]

Why don't you think that's the perimeter? The perimeter of a square with 100 pixels if 400? Do you really think that a highly non-convex shape would make this perimeter a lot higher?

[Prashan]

understood still confused about the e in the middle of the number what does that represent . i thought like in a normal calculator that e meant error ! .

[Sean de Wolski]

e means *10^...

in this case 13613.

[Prashan]

recieving this message when i run regionprops again since i tried to get the perimeter of another hand image how is this possible?

cprops =

6x1 struct array with fields:

Perimeter

Answer 2

[Sean de Wolski]

cprops(:).Perimeter

Will list off the six perimeters (one for each of the six binary objects)

[Prashan]

thanks for this it worked.

now after all the steps i finally managed to get the images perimters calculated . however since im new to matlab i want to know how i could compile this into a program as code so i could scan an imge and run the code from a user interface without havig to declare variables and calculations all over again . the issue basically s that i wish to scan two palms simultaneously and calculate their perimters accordingly from the program how could i do this .