How to save the output image into the folder as shown in matlab?

Hi there! I'm facing a problem when saving the output image that I need. I've successfully saved the image into the file with my desired location. However, the image saved is not the same as shown while running in the MATLAB. The following is my coding.

"imshow(blackMaskedOriImage,[])", when showing the image in MATLAB, I need to include '[]' to show the image that I've needed. If '[]' is not included, there's the only binary image that I'll get.

Therefore, I supposed to have this kind of image saved as shown in A. Instead I get the image as shown in B that saved in my folder.

Very much appreciate if there's a solution for this. Thank you.

A

B

% MAsk the original image and display it.

blackMaskedOriImage =bw.*double(Ia);
figure
imshow(blackMaskedOriImage,[]);%',[]'to display the crop area with dark background
blackMaskedOriImage(~mask) = NaN;
axis on;
title('Masked Outside Region');
path=strcat('C:\Users\Chuah\Desktop\FYP\Aperio_ImageScope\histopathologicalimage\B1_score2\mask+ori(MATLAB)\',srcFile(j).name);
imwrite(bw.*double(I),path);

[Geoff Hayes]

Your code is showing the image

 blackMaskedOriImage =bw.*double(Ia)

but you are saving to file

 bw.*double(I)

What is the difference between I and Ia?

[matlab noob]

Ops! Sorry my fault. Actually I is for original image and Ia is for enhanced image.

Answer 1

[Image Analyst]

Use fullfile(), not strcat().

Don't use path as the name of your variable - you'll destroy a very important built-in variable.

Don't have the image be double. Make it uint8.

Don't set pixels to nan.

Read this link

% Mask image:
blackMaskedOriImage = Ia; % Initialize
blackMaskedOriImage(bw) = 0; % Blacken
% Construct full filename.
folder = 'C:\Users\Chuah\Desktop\FYP\Aperio_ImageScope\histopathological image\B1_score2\mask+ori(MATLAB)\';
fullFileName = fullfile(folder, srcFile(j).name);
% Write to disk.
imwrite(blackMaskedOriImage, fullFileName);

[matlab noob]

Ok, I'll try out the code you provide.

I've set the pixel to nan because later I'll need to extract the features using GLCM without calculating the background.

Thank you.

[Steve Eddins]

I like Image Analyst's recommendation to work with uint8 images. If you need the mask for later computations, then keep it as a separate variable or file. However, if you really want to convert to double so you can set pixels to NaN, then convert to double using the function im2double instead of double. The function im2double scales your uint8 values in the range [0,255] to the range [0,1], which is what MATLAB and Image Processing Toolbox assume is the grayscale range when the type is double. The range mismatch is why you weren't getting the output image file you wanted.

[matlab noob]

Hi Steve! It works! I changed double to im2double as you have recommended. Thank you so much for your help.

Answer 2

[Puja Bharti]

My ques is: if I save the enhanced image then using imshow(NSS_Img,[]) I get the same enhanced image. But if I use imshow(NSS_Img) the image is not the saved enhanced image. Please help. Actually, I want to enhance image X and save it and then crop a small portion from the saved enhanced image. But, the values of NSS_img and the image after saving is not same.

my code is given below:

    X = imread(imfile(image).name);
    filename = imfile(image).name;
    full_file = fullfile('C:\Users\Puja Bharti\Desktop\matlab\',filename);
    [pathname, name, ext] = fileparts(full_file);
    s1 = 'En';
    s2 = filename;
    s = strcat(s1,s2);
    new_name = fullfile(pathname, s)

    if size(X,3)==3
        X = rgb2gray(X);
    end

    grayImage= im2double(X);
    figure('Name','Original image'), imshow(grayImage)

    NSS_img =  NSS(grayImage);     %NSS_img is enhanced image
    whos NSS_img
    figure('Name','final image'), imshow(NSS_img,[])  

    imwrite(NSS_img,new_name,'png','Mode','lossless');