That invocation is precisely right. On my system, it's a shell script called `cleanWhiteboardImage`; this is an actual command I've run, taken from my bash hist

That invocation is precisely right. On my system, it's a shell script called `cleanWhiteboardImage`; this is an actual command I've run, taken from my bash history: cleanWhiteboardImage IMG_20140208_175541.jpg zoomedOut-action-flow-chart.png Also, yes the time it takes to make this work can be problematic. That can be mitigated by shrinking the image, though that decreases the quality of the cleanup. In reality though, I'm fine with it taking a couple seconds. My main motivation wasn't so much to make this 'fast' as it was to automate the process.