If that doesn't work out, you can still use images in text, and the text will appear in your source code!
So say the text image is called img.gif and is in the same folder as your webpage with a width of 200px and a height of 100px...
background: url(img.gif) no-repeat top left;
<h1>This is my heading that I can edit</h1>
Make sure you specify the correct dimensions. Hope this helps