What is leaking memory with this use of getImageData, javascript, HTML5 canvas

Question

I am working with the \'canvas\' element, and trying to do some pixel based manipulations of images with Javascript in FIrefox 4.

The following code leaks memory, an

Answer 1

Oh.. mistake. The memory lookes OK after few test.
But there is another problem.
The size of used memory by tab process is growing when changing the src property of img elements...

Src property = canvas.getContext('2d').toDataURL('image/png') (changing each time);

I've tried to "delete img.src", remove node...