MATLAB: Save image using Guide GUI does not work

gui image saveImage Processing Toolbox

When trying to save an image from my GUI I get the error:

—————————————————————————–

Error using imwrite (line 442)

Expected DATA to be one of these types:

double, single, uint8, uint16, uint32, uint64, int8, int16, int32, int64, logical

Instead its type was matlab.graphics.axis.Axes.

——————————————————————————————-

I want to save an image that I modified, where I added squares and/or other images (see image). This is the code I am using:

first_c= 'C:\Users\';
user_name= getenv('username');
second_c='\Desktop';
com_path= fullfile(first_c,user_name,second_c);
a= handles.axes1;
defaultFileName = fullfile(com_path, '*.png*');
[baseFileName, folder] = uiputfile(defaultFileName, 'Specify a file');
if baseFileName == 0
  % User clicked the Cancel button.
  return;
end
fullFileName = fullfile(folder, baseFileName);
imwrite(a, fullFileName);

————————————————————————————–

Can someone please help me? It is for an important project.

Best Answer

You put some variable into the axes. So you don't need to get that variable back out of that axes -- you can jsut use the same variable you loaded into it. If you did want to get the image out, you'd use getimage()

displayedImage = getimage(handles.axes1);
% Then create fullFileName.  Then save.
imwrite(displayedImage, fullFileName);

But that won't get any graphics you drew over it in the overlay (lines, etc.). To get that you can use exportgraphics().

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MATLAB: Divide an image in half

See this demo. Just copy, paste, and run:

clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
imtool close all;  % Close all imtool figures if you have the Image Processing Toolbox.
workspace;  % Make sure the workspace panel is showing.
format long g;
format compact;
fontSize = 18;
% Change the current folder to the folder of this m-file.
if(~isdeployed)
  cd(fileparts(which(mfilename)));
end
  
% Check that user has the Image Processing Toolbox installed.
hasIPT = license('test', 'image_toolbox');
if ~hasIPT
  % User does not have the toolbox installed.
  message = sprintf('Sorry, but you do not seem to have the Image Processing Toolbox.\nDo you want to try to continue anyway?');
  reply = questdlg(message, 'Toolbox missing', 'Yes', 'No', 'Yes');
  if strcmpi(reply, 'No')
    % User said No, so exit.
    return;
  end
end
% Read in a standard MATLAB gray scale demo image.

folder = fullfile(matlabroot, '\toolbox\images\imdemos');
button = menu('Use which demo image?', 'CameraMan', 'Moon', 'Eight', 'Coins', 'Pout');
if button == 1
  baseFileName = 'cameraman.tif';
elseif button == 2
  baseFileName = 'moon.tif';
elseif button == 3
  baseFileName = 'eight.tif';
elseif button == 4
  baseFileName = 'coins.png';
else
  baseFileName = 'pout.tif';
end
% Read in a standard MATLAB gray scale demo image.
folder = fullfile(matlabroot, '\toolbox\images\imdemos');
% 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') 
% Let's compute and display the histogram.
[pixelCount grayLevels] = imhist(grayImage);
subplot(2, 2, 2); 
bar(pixelCount);
grid on;
title('Histogram of original image', 'FontSize', fontSize);
xlim([0 grayLevels(end)]); % Scale x axis manually.
% Binarize the image
binaryImage = im2bw(grayImage, 0.5);
% Display the original gray scale image.
subplot(2, 2, 2);
imshow(binaryImage, []);
numBlackPixelsTotal = sum(~binaryImage(:));
percentTotal = 100 * numBlackPixelsTotal / (rows * columns);
caption = sprintf('Complete Binary Image has %d Black pixels = %.3f %%', ...
  numBlackPixelsTotal, percentTotal);
title(caption, 'FontSize', fontSize);
% Get the top half.
topHalf = binaryImage(1:floor(rows/2),:);
subplot(2, 2, 3);
imshow(topHalf, []);
% Count the Black pixels in the top half.
numBlackPixelsTop = sum(~topHalf(:));
percentTop = 100 * numBlackPixelsTop / numel(topHalf);
caption = sprintf('Top Half of Binary Image has %d Black pixels = %.3f %%', ...
  numBlackPixelsTop, percentTop);
title(caption, 'FontSize', fontSize);
% Get the bottom half.
bottomHalf = binaryImage(floor(rows/2)+1:end,:);
subplot(2, 2, 4);
imshow(bottomHalf, []);
% Count the Black pixels in the bottom half.
numBlackPixelsBottom = sum(~bottomHalf(:));
percentBottom = 100 * numBlackPixelsBottom / numel(bottomHalf);
caption = sprintf('Bottom Half of Binary Image has %d Black pixels = %.3f %%', ...
  numBlackPixelsBottom, percentBottom);
title(caption, 'FontSize', fontSize);

MATLAB: Problem with working the browsing image in gui

Try this snippet to get a filename of an image or file to read in:

% Have user browse for a file, from a specified "starting folder."
% For convenience in browsing, set a starting folder from which to browse.
startingFolder = 'C:\Program Files\MATLAB';
if ~exist(startingFolder, 'dir')
  % If that folder doesn't exist, just start in the current folder.
  startingFolder = pwd;
end
% Get the name of the file that the user wants to use.
defaultFileName = fullfile(startingFolder, '*.*');
[baseFileName, folder] = uigetfile(defaultFileName, 'Select a file');
if baseFileName == 0
  % User clicked the Cancel button.

  return;
end
fullFileName = fullfile(folder, baseFileName)

Use this snippet to specify a file to save:

% Get the name of the file that the user wants to save.
% Note, if you're saving an image you can use imsave() instead of uiputfile().
startingFolder = userpath
defaultFileName = fullfile(startingFolder, '*.*');
[baseFileName, folder] = uiputfile(defaultFileName, 'Specify a file');
if baseFileName == 0
  % User clicked the Cancel button.
  return;
end
fullFileName = fullfile(folder, baseFileName)

Best Answer

Related Solutions

MATLAB: Divide an image in half

MATLAB: Problem with working the browsing image in gui

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