Image Resizing before loading

Hello Community,

When I read in an image - it is always too big to fit on screen so needs resizing, as below:

>> figure
>> myImage = ('IMG_2512.JPG');
>> imshow(myImage)
Warning: Image is too big to fit on screen; displaying at 17% 
> In imuitools\private\initSize at 71
  In imshow at 282

How can I resize the image beforehand so this error is not a problem, and it speeds up the loading process?

Thanks.

Regards,

10B.

Answer 1

[Image Analyst]

That's not an error. It's not even really a warning - I consider it more of a notification. Just ignore it. If you want to suppress that warning, run this function:

% http://www.mathworks.com/help/matlab/matlab_prog/suppress-warnings.html
function TurnOffWarnings
  try
    % To set the warning state, you must first know the message identifier for the one warning you want to enable. 
    % Query the last warning to acquire the identifier.  For example: 
    % warnStruct = warning('query', 'last')
    % messageID = warnStruct.identifier
    % messageID =
    %    MATLAB:concatenation:integerInteraction
    
    % Turn off this warning "Warning: Image is too big to fit on screen; displaying at 33% "
    warning('off', 'Images:initSize:adjustingMag');
    
    % Get rid of warning about directory already existing: 
    % "Warning: Directory already exists."
    warning('off', 'MATLAB:MKDIR:DirectoryExists');

    % Turn off note "Warning: Added specified worksheet." that appears in the command window.
    warning('off', 'MATLAB:xlswrite:AddSheet');

    % Get rid of warning about roipolyold being deprecated: 
    % "Warning: Function ROIPOLYOLD will be removed in the future. Use ROIPOLY instead"
    warning('off', 'images:removing:function');
    
    % Get rid of warning about wavread() being deprecated: 
    % "Warning: WAVREAD will be removed in a future release. Use AUDIOREAD instead."
    warning('off', 'MATLAB:audiovideo:wavread:functionToBeRemoved');
    
    % Get rid of warning about wavread() being deprecated: 
    % "Warning: figure JavaFrame property will be obsoleted in a future release. For more information see the JavaFrame resource on the MathWorks web site."
    warning('off', 'MATLAB:HandleGraphics:ObsoletedProperty:JavaFrame');
    
    % Turn off warning about variable names being modified if you use readtable() to read in column headers that have spaces in them.
    % "Warning: Variable names were modified to make them valid MATLAB identifiers."
    warning('off', 'MATLAB:table:ModifiedVarnames');

catch ME
    errorMessage = sprintf('Error in function %s() at line %d.\n\nError Message:\n%s', ...
      ME.stack(1).name, ME.stack(1).line, ME.message);
    fprintf(1, '%s\n', errorMessage);
    uiwait(warndlg(errorMessage));
  end
  return; % from TurnOffWarnings

[10B]

Thanks for the response Image Analyst. Actually I'm not very concerned about it as obviously the script continues to run and the next step happens as expected.

I just presumed that this 'forced' resizing was delaying the processing and ultimately adding extra run time.

But if you think its nothing to worry about and should be just ignored then OK, I will follow your advice.

As an aside, I had this code for the resizing (copied from elsewhere):

im = im - min(im(:));
  im = 255 * im / max(im(:));
  imwrite( uint8(im) );

but couldn't get it to work in my workflow. Do you know how to add it in - just so I know how to if it is needed in the future?

Thanks.

[Image Analyst]

You forgot the filename. To scale to 0-255, which is what that does, do this:

im2 = uint8(255*mat2gray(im));
imwrite(im2, filename);

[10B]

Thank you again Image Analyst - Always top quality answers!