There ability to directly add logos or images in a plot does not exist in MATLAB.
As a workaround the following code can be used.
% Test Code to set a logo into figures(plots and graphs)
clear
close
% create the plot/graph
plot(rand(10));
% GET handle to current axes and move the plot axes to the bottom
ha =gca;
uistack(ha,'bottom');
% Creating a new axes for the logo on the current axes
% To create the logo at the bottom left corner of the plot use
% the next two lines
haPos = get(ha,'position');
ha2=axes('position',[haPos(1:2), .1,.04,]);
% To place the logo at the bottom left corner of the figure window
% uncomment the line below and comment the above two lines
% ha2=axes('position',[0, 0, .1,.04,]);
% Adding a LOGO to the new axes
% The logo file(jpeg, png, etc.) must be placed in the working path
[x, map]=imread('peppers.png');
image(x)
% Setting the colormap to the colormap of the imported logo image
colormap (map)
% Turn the handlevisibility off so that we don't inadvertently plot
% into the axes again. Also, make the axes invisible
set(ha2,'handlevisibility','off','visible','off')
