MATLAB: How can i convert the edge line of this image from white to black and the background from black to white

digital image processingimage analysisImage Processing Toolboximage segmentation

I just completed a code and it ran ok, but i have a slight issue with it. the code is to extract the edge of the image of an object in Fourier domain.the code is written below and the image used in the code is attached.
the problem i have with it is to convert the color of the edge line of the resulting image from white to black and the background from black to white.
kindly help insert the appropriate code in the appropriate line to help do the conversion.
% Read in a standard image
Standardimage = 'AEESS2.jpg';
Originalimage = imread(Standardimage);
% Display the original image
imshow(Originalimage);
%Convert Original image to grayscale and display.
grayImage = rgb2gray(Originalimage);
imshow(grayImage);
% Display the original grayscale image.
subplot(2, 2, 1);
imshow(grayImage, [0 255]);
title('Original Grayscale Image in its Spatial Domain', 'FontSize', 10);
% Enlarge the figure to full screen.
% set(gcf, 'Position', get(0,'Screensize'));
set(gcf, 'units','normalized','outerposition',[0 0 1 1]);
% Compute the FFT.
FFTImage = fft2(grayImage);
% Shift the zero frequency location from (0,0)to the center of the display

% and take log in order to have a clearer display.

centeredFFTImage = log(fftshift(real(FFTImage)));
% Display the FFT image.
subplot(2, 2, 2);
imshow(centeredFFTImage, []);
title('Visually Enhanced Frequency Domain of the Original Grayscale Image', 'FontSize', 9);
% Zero out the corners.
window = 30;
FFTImage(1:window, 1:window) = 0;
FFTImage(end-window:end, 1:window) = 0;
FFTImage(1:window, end-window:end) = 0;
FFTImage(end-window:end, end-window:end) = 0;
% Shift the zero frequency location from (0,0)to the center of the display
% and take log in order to have a clearer display.
centeredFFTImage = log(fftshift(real(FFTImage)));
subplot(2, 2, 3);
imshow(centeredFFTImage, []);
title('Visually Enhanced Frequency Domain of the Filtered image', 'FontSize', 10);
% Taking the Inverse FFT to convert the high pass filtered
%image back to Spatial domain.
output = ifft2(FFTImage);
% Display the output.
subplot(2, 2, 4);
imshow(real(output), [0 255]);
title('High Pass Filtered Image converted back to the Spatial Domain', 'FontSize', 10);
Thanks, Best Regards.

Best Answer

Can't you just invert your image:
output = 255 - real(output);
That will invert black and white.
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