MATLAB: About quantization of image

Question

i am trying to do uniform quantization on a gray scale image. i have to generate different images matrix for different K levels using imquantize() function and display all images. please let me know how to do that in MATLAB

Answer 1

Put it in a for loop

grayImage = imread('coins.png');
% Split the image into eight levels by obtaining seven thresholds from multithresh.
for numLevels = 1 : 16
  thresh = multithresh(grayImage, numLevels);
  % Construct the valuesMax vector such that the maximum value
  % in each quantization interval is assigned to the eight levels of the output image.
  valuesMax = [thresh max(grayImage(:))]
  [quant8_I_max, index] = imquantize(grayImage,thresh,valuesMax);
  valuesMin = [min(grayImage(:)) thresh]
  quant8_I_min = valuesMin(index);
  
  % Display both eight-level output images side by side.
  figure;
  imshowpair(quant8_I_min,quant8_I_max,'montage')
  title('Minimum Interval Value           Maximum Interval Value')
  % Set up figure properties:
  % Enlarge figure to full screen.
  set(gcf, 'Units', 'Normalized', 'OuterPosition', [0 0 1 1]);
  % Get rid of tool bar and pulldown menus that are along top of figure.
  set(gcf, 'Toolbar', 'none', 'Menu', 'none');
  % Give a name to the title bar.
  set(gcf, 'Name', 'Demo by ImageAnalyst', 'NumberTitle', 'Off')
end