MATLAB: Generate histogram of HSV quantized image

Question

Hello,

I have tried to quantize the HSV color space but I can not, can anyone help me please?

I want to Quantization HSV Space by assigning 8 level each to hue, saturation and value to give a quantized HSV space with 8x8x8=512 histogram bins.

I have used the following code for that but I am getting an error in rescale function. Can anyone help me to sort out this problem?

rgbImage = imread('1.jpg');

hsvImage = rgb2hsv(rgbImage);

montage(hsvImage,'Size', [1, 3]); title('Before Quantization'); colorbar;

threshRGB = multithresh(hsvImage, 8);

threshForPlanes = zeros(3, 8);

for i = 1:3

threshForPlanes(i, 🙂 = multithresh(hsvImage(:, :, i), 8);

end

quantPlane = zeros(size(hsvImage));

for i = 1:3

value = [0 threshForPlanes(i, 2:end) 1];

quantPlane(:, :, i) = imquantize(hsvImage(:, :, i), threshForPlanes(i, :), value);

end

quantPlane = double(rescale(quantPlane, 0, 1));

figure; montage(quantPlane, 'Size', [1,3]); title('After Quantization');

colormap(parula(8)); colorbar;

% Error: Undefined function 'rescale' for input arguments of type 'double'.

quantPlane = double(rescale(quantPlane, 0, 1));

Thank you.

Answer 1

Why are you calling multithresh() and imquantize() to quantize it. Just call histogram() if you want the histogram. Your subject line says you want to "Generate histogram of HSV quantized image". Quantizing it will not create a histogram. The histogram() function will.