A problem in the loop

Hi,

Please I want to draw a patch from four corner points of each building in the image. However, I do not know how can I create a loop for this purpose.

I posted my codes and I will highly appreciate any help may I get.

aa = imread('test_8bit_vis.tif');

figure, image(aa)

[x, y] = ginput

save My_Coordinates.mat x y

hold on

plot(x,y,'xw');

for ii = 1:length(x-1)

    ind = x(1:4) + 4 * (ii-1);

    patch(x(ind), y(ind),'yellow');

    end

Answer 1

[Image Analyst]

See my code for doing it:

% Display something so we can draw on it.
folder = fileparts(which('office_4.jpg')); % Determine where demo folder is (works with all versions).
baseFileName = 'office_4.jpg';
% Get the full filename, with path prepended.
fullFileName = fullfile(folder, baseFileName);
% Check if file exists.
if ~exist(fullFileName, 'file')
  % File doesn't exist -- didn't find it there.  Check the search path for it.
  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
rgbImage = imread(fullFileName);
imshow(rgbImage, []);
% 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')

message = sprintf('Draw your polygon with left clicks.\nRight click the last point to finish it.');
uiwait(helpdlg(message));
loopCounter = 1;
while loopCounter < 30
  % Let user draw the polygon.
  [~, x, y] = roipolyold;
  % Draw a yellow patch over the image.
  patch(x, y,'yellow');
  
  % Ask user if they want to continue.
  promptMessage = sprintf('Do you want to Continue drawing patches,\nor Cancel to quit drawing?');
  titleBarCaption = 'Continue?';
  button = questdlg(promptMessage, titleBarCaption, 'Continue', 'Cancel', 'Continue');
  if strcmpi(button, 'Cancel')
    break;
  end
  loopCounter = loopCounter + 1;
end

It this meets the requirements, go ahead and please mark it Accepted.

[Nada Kadhim]

Hi Image Analyst, Thank you very much for your help. Yours sincerely, Nada