[HTML5] JSArrayBufferData - memory problem

I’m using some big atlases which contain many images. and when need to display image, I get it by copying the one I need.
The main problem is the memory. All atlases and embedded fonts are stored in JSArrayBufferData . Is it necessary to be stored in JSArrayBuferData ? I check PiratePig demo and there is not using of JSArrayBufferData at all . How can I free the memory used from JSArrayBufferData or not stored at all ?

We support images that are stored in ArrayBuffer, CanvasElement or ImageElement, we tend to start with ImageElement, then convert to CanvasElement then ImageData/ArrayBuffer as needed (if you begin accessing or modifying pixels directly)