Try exportgraphics followed by imresize():
fig1 = figure('Renderer', 'painters');
plot(1:10, 'b-', 'LineWidth', 3);
% Create a temporary filename.
fileName = 'Delete Me.png';
exportgraphics(gcf, fileName);
close(fig1);
% read in temporary image.
rgbImage = imread(fileName);
% Resize to 32x32
image32 = imresize(rgbImage, [32, 32]);
figure
subplot(1, 2, 1);
imshow(rgbImage)
title('Full Size Version', 'FontSize', 20);
subplot(1, 2, 2);
imshow(image32)
title('32-by-32 Size Version', 'FontSize', 20);
% Delete temporary image.
recycle on;
delete(fileName);
g = gcf;
g.WindowState = 'maximized';
