MATLAB: How to detect hand

bounding boxhand detectionimage segmentationregion of interest

INPUT IMAGE:
MATLAB CODE (also attached):
clear all; close all; clc image=imread('a_ASL3.jpg'); BW=binary_image(image); BW = ~BW; st = regionprops(BW, 'BoundingBox' ); for k = 1 : length(st) thisBB = st(k).BoundingBox; rectangle('Position', [thisBB(1),thisBB(2),thisBB(3),thisBB(4)],… 'EdgeColor','r','LineWidth',2 ) end
OUTPUT IMAGE:
PROBLEM I want bounding box just around hand so that I can crop it and do further operations but I am getting image as output in which there are bounding box around every object.

Best Answer

Try this:
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 = 20;
% Read in a color demo image.
folder = 'C:\Users\Explorer\Documents';
baseFileName = 'a_ASL3.jpg';
% Get the full filename, with path prepended.
fullFileName = fullfile(folder, baseFileName);
if ~exist(fullFileName, 'file')
  % Didn't find it there.  Check the search path for it.
  fullFileName = baseFileName; % No path this time.
  if ~exist(fullFileName, 'file')
    % Still didn't find it.  Alert user.
    errorMessage = sprintf('Error: %s does not exist.', fullFileName);
    uiwait(warndlg(errorMessage));
    return;
  end
end
grayImage=imread(fullFileName);
% Get the dimensions of the image.  
% numberOfColorBands should be = 1.
[rows, columns, numberOfColorBands] = size(grayImage);
if numberOfColorBands > 1
  % It's not really gray scale like we expected - it's color.
  % Convert it to gray scale by taking only the green channel.
  grayImage = grayImage(:, :, 2); % Take green channel.
end
% Display the original gray scale image.
subplot(2, 2, 1);
imshow(grayImage, []);
axis on;
title('Original Grayscale Image', 'FontSize', fontSize);
% Enlarge figure to full screen.
set(gcf, 'Units', 'Normalized', 'OuterPosition', [0 0 1 1]);
% Give a name to the title bar.
set(gcf, 'Name', 'Demo by ImageAnalyst', 'NumberTitle', 'Off') 
binaryImage = grayImage < 128;
% Display the image.

subplot(2, 2, 2);
imshow(binaryImage, []);
title('Binary Image', 'FontSize', fontSize);
% Label the image
labeledImage = bwlabel(binaryImage);
measurements = regionprops(labeledImage, 'BoundingBox', 'Area');
for k = 1 : length(measurements)
  thisBB = measurements(k).BoundingBox;
  rectangle('Position', [thisBB(1),thisBB(2),thisBB(3),thisBB(4)],...
  'EdgeColor','r','LineWidth',2 )
end
% Let's extract the second biggest blob - that will be the hand.
allAreas = [measurements.Area];
[sortedAreas, sortingIndexes] = sort(allAreas, 'descend');
handIndex = sortingIndexes(2); % The hand is the second biggest, face is biggest.
% Use ismember() to extact the hand from the labeled image.
handImage = ismember(labeledImage, handIndex) 
% Now binarize
handImage = handImage > 0;
% Display the image.
subplot(2, 2, 3);
imshow(handImage, []);
title('Hand Image', 'FontSize', fontSize);
Related Question