ImageGraph not working

[gpolek]

It is impossible to get image from ImageGraph.get() method because API call return image eg. http://demo.piwik.org/?module=API&method=ImageGraph.get&idSite=7&period=day&date=today&apiModule=UserCountry&apiAction=getCountry&outputType=0&showLegend=1&fontSize=9&aliasedGraph=1&textColor=222222&backgroundColor=FFFFFF&gridColor=CCCCCC&legendAppendMetric=1&format=JSON&token_auth=anonymous
but ApiModule.api_call returns [] if it is not string nor hash.

However, if it is possible can you guide me how to achieve this? I get proper object of ImageGraph but I cannot extract image url or image itself from it.