Hue value of a specific pixel
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I have a segmented image I, I have used labeling to find the segmented objects, and using region props function I have extracted the centroid pixel value.
My question is:
Is there a way to find the hue value of this specific pixel value in my case the centroid ?
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채택된 답변
Image Analyst
2017년 11월 1일
Yes
hsvValues = rgb2hsv(rgbValues);
hueValue = hsvValues(:,:,1);
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Image Analyst
2017년 11월 2일
Centroid will be a floating point number with fractional values, so you need to round it to the nearest integers.
추가 답변 (1개)
Image Analyst
2017년 11월 4일
Why not just get the mean hue of the whole thing?
clc; % Clear the command window.
close all; % Close all figures (except those of imtool.)
clear; % Erase all existing variables. Or clearvars if you want.
workspace; % Make sure the workspace panel is showing.
format long g;
format compact;
fontSize = 25;
%===============================================================================
% Get the name of the image the user wants to use.
baseFileName = 'IMG_7379_2.jpg';
% Get the full filename, with path prepended.
folder = pwd
fullFileName = fullfile(folder, baseFileName);
% Check if file exists.
if ~exist(fullFileName, 'file')
% The file doesn't exist -- didn't find it there in that folder.
% Check the entire search path (other folders) for the file by stripping off the folder.
fullFileNameOnSearchPath = baseFileName; % No path this time.
if ~exist(fullFileNameOnSearchPath, 'file')
% Still didn't find it. Alert user.
errorMessage = sprintf('Error: %s does not exist in the search path folders.', fullFileName);
uiwait(warndlg(errorMessage));
return;
end
end
%===============================================================================
% Read in demo image.
rgbImage = imread(fullFileName);
% Get the dimensions of the image.
[rows, columns, numberOfColorChannels] = size(rgbImage);
% Display the original image.
subplot(1, 2, 1);
imshow(rgbImage, []);
axis on;
caption = sprintf('Original Color Image, %s', baseFileName);
title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
hp = impixelinfo();
% Set up figure properties:
% Enlarge figure to full screen.
set(gcf, 'Units', 'Normalized', 'OuterPosition', [0 0.05 1 0.95]);
% 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')
drawnow;
hp = impixelinfo(); % Set up status line to see values when you mouse over the image.
% Create the region of interest (ROI)
Igray = rgb2gray(rgbImage);
binaryImage = ~imbinarize(Igray);
% Take largest 2 blobs only
binaryImage = bwareafilt(binaryImage, 2);
% Fill them to get rid of noise.
binaryImage = imfill(binaryImage, 'holes');
% Display the mask image.
subplot(1, 2, 2);
imshow(binaryImage, []);
axis on;
caption = sprintf('Binary Image');
title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
hp = impixelinfo();
drawnow;
% Convert rgb to hsv
hsvImage = rgb2hsv(rgbImage);
hueImage = hsvImage(:, :, 1);
% Compute the mean hue within the mask:
meanHue = mean(hueImage(binaryImage))
message = sprintf('The mean hue angle is %f', meanHue);
uiwait(helpdlg(message));
% Measure properties of the blobs.
% props = regionprops(binaryImage, 'Centroid');
댓글 수: 5
Image Analyst
2017년 11월 6일
No, the square root of a squared and b squared, like I said. LAB color space should work for any color.
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