The invention relates to a processing machine (10) or method for processing substantially plate-shaped work pieces (W), preferably made at least partially from wood, wood materials, composite materials or plastics, wherein the processing machine (10) has a processing device (6) for processing a work piece (W) in a processing direction (R), an optical detection device (2), an evaluation unit and a control device (4), wherein: the optical detection device (2) is designed and configured in such a way that it can optically detect front and rear (in relation to the processing direction (6)) end sections (Q1, Q2) of a work piece (W) to be processed, and it provides the evaluation unit with corresponding detection results; the evaluation unit is designed in such a way that it assesses, based on the detection results, whether a coating (B) is present on the front and/or rear end section (Q1, Q2) of the work piece (W) to be processed, and provides the control device (4) with corresponding assessment results; and the control device is designed in such a way that it controls the further processing of the work piece (W) to be processed via the processing device (6) on the basis of the assessment results.