how to calculate otsu threshold value for the matrix given [1 3 4 5 3 2; 4 6 2 4 1 9; 0 4 9 5 8 3; 2 4 9 4 2 1; 0 1 9 3 4 8; 5 6 4 7 3 8]

please help me with the simples code possible.

Answer 1

[Image Analyst]

grayImage = uint8([1 3 4 5 3 2; 4 6 2 4 1 9; 0 4 9 5 8 3; 2 4 9 4 2 1; 0 1 9 3 4 8; 5 6 4 7 3 8])

grayImage = 6×6

1 3 4 5 3 2 4 6 2 4 1 9 0 4 9 5 8 3 2 4 9 4 2 1 0 1 9 3 4 8 5 6 4 7 3 8

threshold = graythresh(grayImage) % Find threshold using Otsu method.

threshold = 0.0196

% If it's uint 8 you want to multiply by 255
threshold = 255 * graythresh(grayImage)

threshold = 5

[Sanaullah Shareef Mohammed]

what if we want to calculate weights, means and varience for each element using loop and printing the minimum of all.

[Image Analyst]

Not sure what that means. An element of the image is a single number and the mean is the value of the pixel, the variance is zero, and the max and min are again the value of the pixel.

If you want it of just the part above the threshold you'd do

grayImage = uint8([1 3 4 5 3 2; 4 6 2 4 1 9; 0 4 9 5 8 3; 2 4 9 4 2 1; 0 1 9 3 4 8; 5 6 4 7 3 8]);
threshold = graythresh(grayImage); % Find threshold using Otsu method.
% If it's uint 8 you want to multiply by 255
threshold = 255 * graythresh(grayImage)

threshold = 5

mask = grayImage > threshold;
meanGrayLevel = mean(grayImage(mask))

meanGrayLevel = 7.9000

varGrayLevel = var(double(grayImage(mask)))

varGrayLevel = 1.4333

stDevGrayLevel = std(double(grayImage(mask)))

stDevGrayLevel = 1.1972

minGrayLevel = min(grayImage(mask))

minGrayLevel = uint8 6

maxGrayLevel = max(grayImage(mask))

maxGrayLevel = uint8 9