MATLAB: How to select roi??

fingerprintImage Processing Toolboxroi

matlab code for how to select region of interest manualy???and extract minutia in that selected region…

Best Answer

How about imrect, or rbbox? Here's a demo for you:
function test1()
clc;  % Clear command window.
clear;  % Delete all variables.
close all;  % Close all figure windows except those created by imtool.
imtool close all;  % Close all figure windows created by imtool.
workspace;  % Make sure the workspace panel is showing.
fontSize = 16;
% Read in a standard MATLAB gray scale demo image.

folder = fullfile(matlabroot, '\toolbox\images\imdemos');
baseFileName = 'cameraman.tif';
% 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.

  fullFileName = baseFileName; % No path this time.

  if ~exist(fullFileName, '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
grayImage = imread(fullFileName);
% Get the dimensions of the image.

% numberOfColorBands should be = 1.

[rows columns numberOfColorBands] = size(grayImage);
% Display the original gray scale image.
subplot(2, 2, 1);
imshow(grayImage, []);
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')
% Prompt user to draw a region on the image.
message = sprintf('Draw a box over the image.\nDouble click inside the box to finish drawing.');
uiwait(msgbox(message));
% Erase all previous lines.

ClearLinesFromAxes();
hBox = imrect;
roiPosition = wait(hBox);
roiPosition
% Erase all previous lines.
ClearLinesFromAxes();
xCoords = [roiPosition(1), roiPosition(1)+roiPosition(3), roiPosition(1)+roiPosition(3), roiPosition(1), roiPosition(1)];
yCoords = [roiPosition(2), roiPosition(2), roiPosition(2)+roiPosition(4), roiPosition(2)+roiPosition(4), roiPosition(2)];
% Plot the mask as an outline over the image.
hold on;
plot(xCoords, yCoords, 'linewidth', 2);
% Convert to integer
xCoords = int32(xCoords);
xCoords = int32(xCoords);
% Crop the image
croppedImage = imcrop(grayImage, roiPosition);
subplot(2, 2, 2);
imshow(croppedImage, []);
title('Cropped Grayscale Image', 'FontSize', fontSize);
% Now read in image 2
% Read in a standard MATLAB gray scale demo image.
folder = fullfile(matlabroot, '\toolbox\images\imdemos');
baseFileName = 'moon.tif';
% 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.
  fullFileName = baseFileName; % No path this time.
  if ~exist(fullFileName, '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
grayImage2 = imread(fullFileName);
% Get the dimensions of the image.
% numberOfColorBands should be = 1.
[rows2 columns2 numberOfColorBands2] = size(grayImage2);
% Make sure roiPosition doesn't go outside the image...
% Display the second gray scale image.
subplot(2, 2, 3);
imshow(grayImage2, []);
title('Second Grayscale Image', 'FontSize', fontSize);
% Crop the second image
croppedImage2 = imcrop(grayImage2, roiPosition);
subplot(2, 2, 4);
imshow(croppedImage2, []);
title('Cropped Second Grayscale Image', 'FontSize', fontSize);
%====================================================================================================================== 
% Erases all lines from the image axes.  The current axes should be set first using the axes()
% command before this function is called, as it works from the current axes, gca.
function ClearLinesFromAxes()
  axesHandlesToChildObjects = findobj(gca, 'Type', 'line');
  if ~isempty(axesHandlesToChildObjects)
    delete(axesHandlesToChildObjects);
  end
  return; % from ClearLinesFromAxes
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