Draw a shape over an object

I = imread('board.tif');
figure, imshow(I);
label_str = cell(3,1);
conf_val = [85.212 98.76 78.342]; 
for ii=1:3
    label_str{ii} = ['Confidence: ' num2str(conf_val(ii),'%0.2f') '%'];
end
position = [23 373 60 66;35 185 77 81;77 107 59 26];
RGB = insertObjectAnnotation(I, 'rectangle', position, label_str,'TextBoxOpacity', 0.9, 'FontSize', 18);
figure, imshow(RGB), title('Annotated chips');