Calculating absolute values with scaling

void convertScaleAbs(InputArray src, OutputArray dst, double alpha=1, double beta=0)
        - Scales, calculates absolute values, and converts the result to 8-bit.

Parameters:

• src – input array.
• dst – output array.
• alpha – optional scale factor.
• beta – optional delta added to the scaled values.

 You can find some applications here - Application1, Application2.