rhino.m

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clc;
close all;
workspace;
clear;
fontSize = 16;

tic
% Read in sample demo video shipped with MATLAB.
vidobj = VideoReader('kirmizitop.avi');
NumFrames = vidobj.NumberOfFrames;

% Prepare a figure to show the images
% in the upper portion of the screen.
figure;
screenSize = get(0, 'ScreenSize');
newWindowPosition = [1 screenSize(4)/2 - 70 screenSize(3) screenSize(4)/2];
set(gcf, 'Position', newWindowPosition); % Maximize figure.

% Find the max gray level over all frames.
level = -1;

for m=1:NumFrames
    thisFrame = read(vidobj, m);
    
    if ndims(thisFrame) > 1
        thisFrame = rgb2gray(thisFrame);
    end
    
    subplot(1,2,1);
    
    imshow(thisFrame);
    
    drawnow; % Force display to update.
    
    level = max([level, max(thisFrame(:))]);
    
    fprintf('After frame %d, the max gray level is %d.\n', m, level);
    
    if level == intmax(class(thisFrame))
        % No need to check the rest of the frames,
        % because we're already at the limit.
        break;
    end
end

message = sprintf('The max gray level is %.3f', level);

uiwait(msgbox(message));

for frameNumber = 1:NumFrames
    fprintf('Processing frame %d. ', frameNumber);
    thisFrame = read(vidobj, frameNumber);
    if ndims(thisFrame) > 1
        thisFrame = rgb2gray(thisFrame);
    end
    subplot(1,2,1);
    cla reset; % Get rid of prior images and text.
    imshow(thisFrame);
    caption = sprintf('Frame #%d', frameNumber);
    title(caption, 'FontSize', fontSize);

    % Threshold the image.
    binaryImage = thisFrame > level-10;
    % Note: no need for the "& thisFrame <= level+10" criteria
    % since level is already the max value.
    binaryImage = bwareaopen(binaryImage,15);
    subplot(1,2,2);
    cla reset; % Get rid of prior images and text.
    imshow(binaryImage)
    title(caption, 'FontSize', fontSize);
    drawnow; % Force display to update.
    hold on

    % Label the image.
    labeledImage = bwconncomp(binaryImage,8);
    measurements = regionprops(labeledImage,'BoundingBox','Centroid');
    if length(measurements) == 0
        % No blobs found.
        fprintf('Done!\n');
        continue; % Skip to the next frame.
    end

    totalNumberOfBlobs = length(measurements);

    for blobNumber = 1:totalNumberOfBlobs
        bb = measurements(blobNumber).BoundingBox;
        bco = measurements(blobNumber).Centroid;
        rectangle('Position',bb,'EdgeColor','r','LineWidth',2)
        plot(bco(1),bco(2),'-m+')
        myCaption = sprintf('(x=%.1f, y=%.1f)', bco(1), bco(2));
        text(bco(1)+15,bco(2), myCaption,...
            'FontName','Arial','FontWeight','normal',...
            'FontSize',12,'Color','blue');
        set(gca,'xdir','normal')
        set(gca,'ydir','reverse')
        axis on;
    end

    drawnow; % Force display to update.

    fprintf('Done!\n');

end

hold off
toc
uiwait(msgbox('Execution Ended'));