I need to correct the script for coloring map

%## Edited so that code runs here
clc;
close all;
clear;

% Read the geological map
% [file, path] = uigetfile('*.jpg', 'Select the Geological Map File');
path = './';
file = 'Geological map of Mobrun Sulfied.jpg';
map_image = imread(fullfile(path, file));

% Display the original map
figure;
imshow(map_image);
title('Original Map');

% Convert to RGB if the image is grayscale
if size(map_image, 3) == 1
    map_image = cat(3, map_image, map_image, map_image);
end

% Define masks for regions based on RGB values
% Inspect the RGB values of each region using 'impixelinfo' or similar
% Example: Rhyolite, Andesite, and Meta-sediments regions

% Replace these thresholds with specific RGB ranges based on your map
ryolite_mask = (map_image(:,:,1) > 200 & map_image(:,:,2) < 100 & map_image(:,:,3) < 100); % Example: Red shades
andesite_mask = (map_image(:,:,1) < 100 & map_image(:,:,2) > 150 & map_image(:,:,3) < 100); % Example: Green shades
meta_sediments_mask = (map_image(:,:,1) < 100 & map_image(:,:,2) < 100 & map_image(:,:,3) > 150); % Example: Blue shades

% Create a copy of the map for coloring
colored_map = map_image;

% Apply colors to the masks
% Rhyolite - Red
colored_map(:,:,1) = colored_map(:,:,1) + uint8(ryolite_mask) * 255; % Red channel
colored_map(:,:,2) = colored_map(:,:,2) - uint8(ryolite_mask) * 255; % Green channel
colored_map(:,:,3) = colored_map(:,:,3) - uint8(ryolite_mask) * 255; % Blue channel

% Andesite - Green
colored_map(:,:,1) = colored_map(:,:,1) - uint8(andesite_mask) * 255; 
colored_map(:,:,2) = colored_map(:,:,2) + uint8(andesite_mask) * 255; 
colored_map(:,:,3) = colored_map(:,:,3) - uint8(andesite_mask) * 255; 

% Meta-sediments - Blue
colored_map(:,:,1) = colored_map(:,:,1) - uint8(meta_sediments_mask) * 255; 
colored_map(:,:,2) = colored_map(:,:,2) - uint8(meta_sediments_mask) * 255; 
colored_map(:,:,3) = colored_map(:,:,3) + uint8(meta_sediments_mask) * 255; 

% Display the colored map
figure;
imshow(colored_map);
title('Colored Geological Map');

% Save the colored map
imwrite(colored_map, 'Colored_Geological_Map_Automatic.jpg');

[Cris LaPierre]

As shown below, your RGB thresholds are not selecting anything in the image. I'm not sure what to expect for a grayscale image, but based on the comments in the script, I'd suggest revisiting your threshold values.

% Define masks for regions based on RGB values

% Inspect the RGB values of each region using 'impixelinfo' or similar

% Example: Rhyolite, Andesite, and Meta-sediments regions

My suspicion is the hatching or texturing used to 'color' the image will make it challenging for a thresholding approach to produce the desired results.

map_image = imread('Geological ma...n Sulfied.jpg');

% Replace these thresholds with specific RGB ranges based on your map
ryolite_mask = (map_image(:,:,1) > 200 & map_image(:,:,2) < 100 & map_image(:,:,3) < 100); % Example: Red shades
andesite_mask = (map_image(:,:,1) < 100 & map_image(:,:,2) > 150 & map_image(:,:,3) < 100); % Example: Green shades
meta_sediments_mask = (map_image(:,:,1) < 100 & map_image(:,:,2) < 100 & map_image(:,:,3) > 150); % Example: Blue shades

figure
imshow(ryolite_mask)

figure
imshow(andesite_mask)

figure
imshow(meta_sediments_mask)

Answer 1

[Les Beckham]

You need to reexamine the logic you are using to determine the masks. All three masks are all zero, thus no coloring.

% clc;
% close all;
% clear;
% 
% % Read the geological map
% [file, path] = uigetfile('*.jpg', 'Select the Geological Map File');
% map_image = imread(fullfile(path, file));
dir

.                              ..                             Geological ma...n Sulfied.jpg  

map_image = imread('Geological ma...n Sulfied.jpg');

% Display the original map
figure;
imshow(map_image);
title('Original Map');

% Convert to RGB if the image is grayscale
if size(map_image, 3) == 1
    map_image = cat(3, map_image, map_image, map_image);
end

% Define masks for regions based on RGB values
% Inspect the RGB values of each region using 'impixelinfo' or similar
% Example: Rhyolite, Andesite, and Meta-sediments regions

% Replace these thresholds with specific RGB ranges based on your map
ryolite_mask = (map_image(:,:,1) > 200 & map_image(:,:,2) < 100 & map_image(:,:,3) < 100); % Example: Red shades
andesite_mask = (map_image(:,:,1) < 100 & map_image(:,:,2) > 150 & map_image(:,:,3) < 100); % Example: Green shades
meta_sediments_mask = (map_image(:,:,1) < 100 & map_image(:,:,2) < 100 & map_image(:,:,3) > 150); % Example: Blue shades

whos

  Name                       Size                 Bytes  Class      Attributes

  andesite_mask            584x711               415224  logical              
  ans                        1x53                   106  char                 
  map_image                584x711x3            1245672  uint8                
  meta_sediments_mask      584x711               415224  logical              
  ryolite_mask             584x711               415224  logical              

nnz(ryolite_mask) %<<< Your masks are all zeros, so you get no colors

ans = 0

nnz(andesite_mask)

ans = 0

nnz(meta_sediments_mask)

ans = 0

% Create a copy of the map for coloring
colored_map = map_image;

% Apply colors to the masks
% Rhyolite - Red
colored_map(:,:,1) = colored_map(:,:,1) + uint8(ryolite_mask) * 255; % Red channel
colored_map(:,:,2) = colored_map(:,:,2) - uint8(ryolite_mask) * 255; % Green channel
colored_map(:,:,3) = colored_map(:,:,3) - uint8(ryolite_mask) * 255; % Blue channel

% Andesite - Green
colored_map(:,:,1) = colored_map(:,:,1) - uint8(andesite_mask) * 255; 
colored_map(:,:,2) = colored_map(:,:,2) + uint8(andesite_mask) * 255; 
colored_map(:,:,3) = colored_map(:,:,3) - uint8(andesite_mask) * 255; 

% Meta-sediments - Blue
colored_map(:,:,1) = colored_map(:,:,1) - uint8(meta_sediments_mask) * 255; 
colored_map(:,:,2) = colored_map(:,:,2) - uint8(meta_sediments_mask) * 255; 
colored_map(:,:,3) = colored_map(:,:,3) + uint8(meta_sediments_mask) * 255; 

% Display the colored map
figure;
imshow(colored_map);
title('Colored Geological Map');

% Save the colored map
imwrite(colored_map, 'Colored_Geological_Map_Automatic.jpg');

Answer 2

[Cris LaPierre]

The reason your masks are all 0 is because all 3 channels have the same value. You can confirm this using the imageViewer app. Zoom in until you see the individual pixel values (or use the approach suggested in the comments provided in the script).

Your masks apply a different threshold value to each channel. Since the values are the same in all 3 channels, the result will always be zero. For example, consider your ryolite mask.

ryolite_mask = (...

map_image(:,:,1) > 200 & ...

map_image(:,:,2) < 100 & ...

map_image(:,:,3) < 100);

Since this image is 'colored' using textures rather that gray tones, I do not think this approach will produce your desired result.