1. A method for detecting an error in printed images generated by a printing press including: providing a scanning color camera; using said scanning color camera for recording a reference image having a reference image pixel field consisting of several reference image pixels; determining a maximum value and a minimum value of amplitude values of said several reference image pixels in said reference image pixel field; storing said maximum value and said minimum value of each said reference image pixel as its reference image; producing a plurality of actual printed images in the course of an ongoing printing process using said printing press; using said scanning color camera for recording said actual images having an actual image pixel field consisting of several actual image pixels; determining a maximum value and a minimum value of amplitude values of said several actual image pixels in said actual image pixel field; determining a deviation between said reference image pixel amplitude value and said actual image pixel amplitude value; providing a first, lower decision threshold value for said deviation and a second, higher decision threshold value for said deviation; and classifying said printed product as having poor quality when said deviation exceeds both of said first and second decision values.