An improved ROI segmentation image processing system substantially masks non-ROI image data from a digital image to produce a ROI segmented image for subsequent digital processing. The nonlinearity associated with the conventional strip’s medial domain is considerably greater than that which is associated with its lateral domains. Then, the accelerator opening for calculating a power needed to run the vehicle is set at the sum of the offset opening and an pedal opening corresponding to the amount of depression of the accelerator pedal.