A digital-imaging based code symbol reading system which automatically detects hand-induced vibration when the user attempts to read one or more 1D and/or 2D code symbols on an object, and controls system operation in order to reduce motion blur in digital images captured by the hand-supportable system, whether operated in a snap-shot or video image capture mode. An accelerometer sensor is used to automatically detect hand/system acceleration in a vector space during system operation. In a first embodiment, digital image capture is initiated when the user manually depresses a trigger switch, and decode processed only when the measured acceleration of the hand-supportable housing is below predetermined acceleration threshold levels. In another embodiment, digital image capture is initiated when an object is automatically detected in the field of view of the system, and decode processed only when the measured acceleration of the hand-supportable housing is below predetermined acceleration threshold levels.