Convert gray to rgb

Question

Raja Ahmad Shurim Raja Zainol 2021-1-13

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/716293-convert-gray-to-rgb

评论： Image Analyst 2021-1-15

Hey I want to change my gray image back to rgb.

This is my code

I1 = '3 new.jpeg';
img = imread(I1);
img_grey = rgb2gray(img);
A = img(:,:,3);  
second_img = imsubtract(A, img_grey);
final_img = im2bw(second_img, 0.09);
imshow(final_img);
title('Final Img','fontsize',20);
rgbImage=ind2rgb(final_img,jet(256));
imshow (rgbImage);

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Walter Roberson 2021-1-14

在 MATLAB Online 中打开

rgbImage=ind2rgb(uint8(final_img), jet(256));

You will not be able to convert it back to the original color.

However it would be possible to use the binary image to select parts of the original image to stay the same and convert everything else to black.

finalrgb = img.*uint8(final_img) ;

Raja Ahmad Shurim Raja Zainol 2021-1-14

when i using finalrgb = img.*uint8(final_img) ; in normal file it will show the final image but when i try to sub into gui, it cannot show the final image, why?

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Answer 1

Image Analyst 2021-1-14

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/716293-convert-gray-to-rgb#answer_598345

在 MATLAB Online 中打开

How did you call the display function, such as imshow(), in both cases? It should work the same. Are you using GUIDE or App Designer for the "GUI" method?

To change your gray scale image back into the original RGB image, you simply assign it:

img_grey = img;

That should work as long as you still have img available.

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Raja Ahmad Shurim Raja Zainol 2021-1-15

在 MATLAB Online 中打开

i am using the GUIDE, below is my code, i try to make the when i load one image, it can detect the blue or colour in the picture and show the final image of the blue or red colour section, i still new at this image processing

% --- Executes on button press in loadimage.
function loadimage_Callback(hObject, eventdata, handles)
% hObject    handle to loadimage (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
global I1
I1=imread(uigetfile('*.jpeg'));
subplot('Position', [0.2 0.2 0.6 0.6]);
imshow(I1);
% --- Executes on button press in pushbutton2.
function pushbutton2_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton2 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
global I1
img_grey = rgb2gray(I1);
A = I1(:,:,1);  %1=red 2=green 3=blue
almostfinal_img = imsubtract(A, img_grey);
final_img1 = im2bw(almostfinal_img, 0.09);
img_grey=img;GUID
subplot('Position', [0.2 0.2 0.6 0.6]);
title('Position Red','fontsize',20);
% --- Executes on button press in pushbutton3.
function pushbutton3_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton3 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
global I1
img_grey = rgb2gray(I1);
B = I1(:,:,3);  %1=red 2=green 3=blue
almostfinal_img2 = imsubtract(B, img_grey);
final_img = im2bw(almostfinal_img2, 0.06);
subplot('Position', [0.2 0.2 0.6 0.6]);
imshow(final_img);
title('Position Blue','fontsize',20);