How to get exact position of text with respect to figure row, column in Matlab

In the following code segment I am trying to get the exact position of the text bounding box with respect to the figure pixel coordinates( row and column) to eventually be able to crop off that part of figure ( from array img ). However what I get from textBox is not very helpful! some negative numbers!! can anyone provide me some tips

    hFigure = figure('Color', 'w','position',...
    [1600 200 600 250]...
    ,'MenuBar', 'none', 'ToolBar', 'none');

    axis off
    axis([0 1 0 1]); 

    hText=text('String','T','fontsize',100,'color','r',...
       'fontname','Times New Roman',...
    'HorizontalAlignment','left','VerticalAlignment','bottom',...
     'BackgroundColor',[.8 .8 .8],'EdgeColor','r');
    set(hText, 'Units','Pixels');
    textBox=get(hText, 'Extent');%[left,bottom,width,height]
    figBox = get(hFigure,'Position');

    imageData = getframe(hFigure);         

    img = imageData.cdata; 

    %using textBox and imgBox:
    imgText=img(?:?,?:?,3);  **% this is what I want to do**

Please refer to this image:

Answer 1

[Geoff]

I'm not sure about the general case, but here you could exploit the fact that your image bounds are not white:

[y,x] = find( img(:,:,1)~=255 & img(:,:,2)~=255 & img(:,:,3)~=255 );
tl = min([y x]);
br = max([y x]);
image(img(tl(1):br(1), tl(2):br(2),:));

Answer 2

[per isakson]

The parent of an text-object is an axes-object. The extent of the text-object is relative to the axes-object. Use pixels for all objects. This is a start

    axis off
    axis([0 1 0 1]); 
    axh = gca;
    set( axh, 'units', 'pixel' )
    ax_pos  = get( axh, 'Position' );

    hText=text( 'units', 'pixel', ...