'**SUMMARY**
Retrieve a preview-quality Image-object from the scanner.
**RETURNS**
A SimpleCV Image.  Note that whatever the scanner mode is,
SimpleCV will return a 3-channel, 8-bit image.
**EXAMPLES**
>>> scan = Scanner()
>>> scan.getPreview().show()'

def getPreview(self):

    self.preview = True
    img = Image(self.device.scan())
    self.preview = False
    return img
