How can I show 10 pixels width in all directions for an image?

I am trying to find a block of the image, such as, the perimeter of the image, 10 pixels width in all directions. Can you please advise?

[darova]

The question is unclear. Can you explain more? Show the image

[Hadeel H]

I have attached the image, I need to show 10 pixels width of the image

Answer 1

[Walter Roberson]

img = imread('https://www.mathworks.com/matlabcentral/answers/uploaded_files/638445/download.jpg');
n = floor(size(img,2)/2);
leftb = imbinarize(rgb2gray(img(:,1:n,:)));
left = repmat(im2uint8(leftb), [1 1 size(img,3)]);
right = img(:,n+1:end,:);
newimg = [left,right];
imshow(newimg)

[Hadeel H]

Awesom, Thank you very much.

Answer 2

[Adam Danz]

Clarified question in comment below:

> want to display the same image below but half colored and half binary!

Follow the steps in this blog.

figure();
tiledlayout(1,3,'Padding','none','TileSpacing','tight')
rgb = imread('download.jpg');
nexttile()
imshow(rgb);
title('Original image')

nexttile()
imshow(rgb);
I = rgb2gray(rgb);
hold on
h = imshow(I); 
[M,N] = size(I);
halfway = round(N/2);
alpha_data = [ones(M,halfway),false(M,N-halfway)];
set(h, 'AlphaData', alpha_data);
title('Half grayscale')

nexttile()
imshow(rgb);
BW = imbinarize(I);
hold on
h = imshow(BW); 
[M,N] = size(I);
halfway = round(N/2);
alpha_data = [ones(M,halfway),false(M,N-halfway)];
set(h, 'AlphaData', alpha_data);
title('Half binary')

[Hadeel H]

how about Change half of the image into binary format, i.e. starting from the center as white, the remaining as black? I have tried this code below but it is not working

[i,map] = imread('flower.jpg');
[M N]= size(i);
BW = im2bw(i,map,0.4);
for a = 1:M
   for j=1:N
       if j>N/2 && BW(a,j)>128
           BW(a,j)=255;
       end
   end
end
imshow(BW)

advise please

[Adam Danz]

Is this related to the original question?

[Hadeel H]

yes

[Adam Danz]

> How can I show 10 pixels width in all directions for an image?

> I am trying to find a block of the image, such as, the perimeter of the image, 10 pixels width in all directions.

> how about Change half of the image into binary format, i.e. starting from the center as white, the remaining as black?

These three goals are all completely different and unclear. I'm eager to help you but the goal has to be crystal clear before I can invest more time.

[Hadeel H]

let me state the question again and I hope it will be clear this time,.... I am tryig to convert and display half of my colored image into a binary image.

[Adam Danz]

What half? You mentioned something about the center but I don't know how that translates to half.

Is the colored image an RGB image?

How is the image read in?

How should the colors be converted to binary (black and white)?

Is this the image you're converting?

What's not working with the code you shared earlier?

[Hadeel H]

My code is converting half of the image into gray level, I want a code to convert half of the image into binary (Like half of the image to be colored and the other half to be binary)

[Adam Danz]

When I run your code using the image you provided I get an error in this line,

j>N/2 && BW(a,j)>128

because BW has a size of 183x276 but j can be up to 827 which is more columns than in BW. So I can't see what your code is doing.

It's also not clear to me what the goal is.

I don't know what "half of the image" means.

It's not clear how the flower image should be converted to binary. Which colors should be white and which colors should be black? See imbinarize function - it may help you.

I cannot provide further help until every detail of the goal is completely clear.

[Adam Danz]

Hadeel H's answer moved here as a comment.

It is exactly something like this image attached below, but I need to have half of the image to be colored and the other half binary (It does not matter which color should be black or white, you can choose any) I just need the code to do it because the code that I have already provided is just converting half of the image into gray which is not what I am looking for .

[Adam Danz]

That image is fully binarized but you've mentioned that you want half of the image to be binary and it's still unclear what defines half.

Also, that image is originally grayscale whereas the image you shared is in color. If the color image you shared is converted to grayscale and then to binary, this is the result.

RGB = imread('https://www.mathworks.com/matlabcentral/answers/uploaded_files/638445/download.jpg');
I = rgb2gray(RGB);
BW = imbinarize(I);
figure()
tiledlayout(1,2)
nexttile()
imshow(RGB)
nexttile()
imshow(BW)

[Hadeel H]

well, I will try to elaborate more because you are almost close. I attached an image below which shows half of the image colored and the other half is gray, I want to replace the gray with binary , so I want to display the same image below but half colored and half binary! I hope it is clear now

[Adam Danz]

Your comment above is clear. If that image was shared from the beginning, it would have save lots and time and back-and-forth Q&A.

But I still don't know what that has to do with your original question, "How can I show 10 pixels width in all directions for an image?"

[Adam Danz]

See updated answer.