Can I threshold this further if so how?

Hi I have this image:

is there anyway I could process this further so that I am only left with an image with only parts like this:

I have used this code to produce this so far:

I = imread('Scan4Loc1.png');
A = rgb2gray(I)
imshow(A)
J = filter2(fspecial('sobel'),A);
min_matrix = min(J(:))
max_matrix = max(J(:))
figure
imshow(J)
K = mat2gray(J);
min_image = min(K(:))
max_image = max(K(:))
figure
imshow(K)

Answer 1

[Prajit T R]

Hi Oliver. I think the im2bw function may be of help to you. I tried the following code with the image you had attached and it seems to be working fine. Of course, depending upon your use-case, you would have to manually try different values for the variable 'level' until you get it right. The value 0.515 seems to be appropriate for this particular image.

I = imread('image.png');
level=0.515
A = rgb2gray(I)
imshow(A)
BW = im2bw(I, level)
figure
imshow(BW)

Cheers