How to visualise data value with x-y coordinate in an image
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Hello, suppose I have x-y coordinate and z value as the grades of the points. How can I visualize my data in 2-D colormap ? (I want to show x-y cordinate and different colors for different values at every points inside the image). I am attachng sample data text file and regarding image.
Please help.
2 Comments
Walter Roberson
on 15 Sep 2019
I suspect you want griddedInterpolant()
Along with a colormap such as 'hot' or perhaps 'autumn'
Answers (1)
Image Analyst
on 15 Sep 2019
Try something like
data = dlmread(filename, ' ');
x = data(:, 1);
y = data(:, 2);
grayLevel = data(:, 3);
grayImage = zeros(ceil(max(y)), ceil(max(x)));
for k = 1 : length(x)
row = round(y(k));
col = round(x(k));
grayImage(row, col) = grayLevel(k);
end
grayImage = mat2gray(grayImage);
imshow(grayImage, 'ColorMap', jet(256));
colorbar;
4 Comments
Image Analyst
on 15 Sep 2019
Not only the blue, but for most of them. There are 181 pixels that are not zero. But most of your image locations do not have a gray level defined for them, so they are left as zero and appear as blue.
data = dlmread('md1.txt', ' ');
x = data(:, 1);
y = data(:, 2);
grayLevel = data(:, 3);
grayImage = zeros(ceil(max(y)), ceil(max(x)));
for k = 1 : length(x)
row = max([1, round(y(k))]);
col = max([1, round(x(k))]);
grayImage(row, col) = grayLevel(k);
fprintf('Assigning %d to row %d, column %d.\n', grayLevel(k), row, col);
end
minGL = min(grayImage(:))
maxGL = max(grayImage(:))
grayImage = mat2gray(grayImage);
imshow(grayImage, [], 'ColorMap', jet(256));
colorbar;
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