How do I add custom gridlines on my image?
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So I'm trying to program an image converter and trying to get some gridlines on it.
axis equal;
imagesc(secondlevelTIFF, scale) %read matrix into figure
axis equal;
colormap(jet) %makes it into jet
axis on;
grid on;
colorbar;
temp=[[sprintf('fig%03d', i)],'.tif']; %name current figure file
fpath = [I have my path here]; %set file directory
saveas(gcf, fullfile(fpath, temp));
This is my current code with the 'secondlevelTIFF' being my image. I'm trying to add custom gridlines. The image file I have is 500*500 pixels and i want gridlines at 50 and 150 pixels. How do I add these gridlines so that they are on the top of my final image file?
1 Comment
Clay Swackhamer
on 17 Oct 2018
If you are still working on this I wrote a simple function to put a grid on an image. It is on the file exchange here
Answers (2)
Image Analyst
on 21 Jan 2017
Edited: Image Analyst
on 21 Jan 2017
Either burn the lines into your image like this:
[rows, columns, numberOfColorChannels] = size(secondlevelTIFF);
for row = 1 : 50 : rows
secondlevelTIFF(row, :) = 255;
end
for col = 1 : 50 : columns
secondlevelTIFF(:, col) = 255;
end
(this will change your image), or draw a line in the overlay above your image like this
hold on;
for row = 1 : 50 : rows
line([1, columns], [row, row], 'Color', 'r');
end
for col = 1 : 50 : columns
line([col, col], [1, rows], 'Color', 'r');
end
This will not make changes to the image array itself - it will just place lines into the graphic overlay. Adapt spacing and offset as needed.
2 Comments
Image Analyst
on 21 Jan 2017
Edited: Image Analyst
on 21 Jan 2017
You implement it by coping and pasting that code I gave you into your code in the text editor window after you've displayed your image. It's very basic MATLAB skills. You have to learn how to write code into editor windows and how to debug them. If you already know how to do that, then I really don't understand your question at all. Here is a complete m-file for you:
secondlevelTIFF = imread('moon.tif');
imshow(secondlevelTIFF);
axis on;
[rows, columns, numberOfColorChannels] = size(secondlevelTIFF);
hold on;
for row = 1 : 50 : rows
line([1, columns], [row, row], 'Color', 'r');
end
for col = 1 : 50 : columns
line([col, col], [1, rows], 'Color', 'r');
end
And here is what it looks like:
Star Strider
on 21 Jan 2017
You have to create a figure object, then put the gridlines on top of the image.
figure(1)
imagesc(secondlevelTIFF, scale) %read matrix into figure
set(gca, 'Layer','top')
... REST OF YOUR CODE ...
7 Comments
Image Analyst
on 26 Jan 2017
Hosup, if you have R2016b you can run the new function xticks():
xticks([50,300]);
There is a similar function, yticks().
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