When a big image(~3MB) is loaded into the ImageEditor ( with enabled CanvasMode) sometimes the image is not loaded into the controls or the whole page crashes. The issue could be reproduced in Google Chrome, with the 2013 Q1 SP1 version of the controls.
There seems to be performance issues in Chrome related to the drawImage method, which is the essential method to edit the raster image - https://code.google.com/p/chromium/issues/detail?id=117949&q=canvas%20large%20images&colspec=ID%20Pri%20M%20Iteration%20ReleaseBlock%20Cr%20Status%20Owner%20Summary%20OS%20Modified and https://code.google.com/p/chromium/issues/detail?id=121780&q=canvas%20large%20images&colspec=ID%20Pri%20M%20Iteration%20ReleaseBlock%20Cr%20Status%20Owner%20Summary%20OS%20Modified For the time being this browser behaviour couldn't be worked around.