Save an image with a plot

Hey, see if anyone can fix a problem I have. I add an example using the sample image 'cameraman.tif', the image of the real code is another one but to get an idea it works perfectly.

I need to highlight the detected outline, so what I came up with was to get the pixel coordinates and represent them on top of the image by saying that these points are thicker.

Also, I make a crop of the image and I need to show in the original image the crop rectangle used.

When I save it, I want the highlighted pixels to look white and the square to look any other color, for example red.

Do you have any ideas on how to make the image as tight as possible so that the white pixels look white and not black?

Translated with www.DeepL.com/Translator (free version)

I = imread('cameraman.tif');
BW = edge(I,'canny');
[J,rect2] = imcrop(BW);

[r,c] = find ( BW == 1 );
pP = [c r];

f = figure;
imshow(I)
hold on
plot(pP(:,1),pP(:,2),'.w','MarkerSize',5)
rectangle('Position',rect2,'EdgeColor','red','LineWidth',3)
print('TH.tif','-dtiff')

What i want to obtain

What i obtain using print.

Answer 1

[Ameer Hamza]

Try this

I = imread('cameraman.tif');
BW = edge(I,'canny');
[J,rect2] = imcrop(BW);
[r,c] = find ( BW == 1 );
pP = [c r];
f = figure;
ax = axes;
imshow(I)
hold on
plot(pP(:,1),pP(:,2),'.w','MarkerSize',5)
rectangle('Position',rect2,'EdgeColor','red','LineWidth',3)
frame = getframe(gca);
imwrite(frame.cdata, 'TH.tif')

If you are using R2020a, then MATLAB also introduced exportgraphics

I = imread('cameraman.tif');
BW = edge(I,'canny');
[J,rect2] = imcrop(BW);
[r,c] = find ( BW == 1 );
pP = [c r];
f = figure;
ax = axes;
imshow(I)
hold on
plot(pP(:,1),pP(:,2),'.w','MarkerSize',5)
rectangle('Position',rect2,'EdgeColor','red','LineWidth',3)
exportgraphics(gca,'TH.tif')

[Alejandro Fernández]

Both works! Thank you so so much!!

[Ameer Hamza]

Glad to be of help.