System and methods for detecting malfunctioning nozzles in a digital printing press

method of identifying at least one malfunctioning nozzle in a digital printing press, said digital printing press including a plurality of nozzles, the method comprising the procedures of:

• printing a design on a substrate;
• acquiring at least one image of the printed design;
• identifying at least one artifact in the acquired image;
• and
• identifying said malfunctioning nozzle and classifying said at least one malfunction nozzle according to at least a portion of a combined pattern by:
• printing a combined pattern, said combined pattern including a respective combined color pattern for each color being printed, each said combined color pattern including a plurality of rows, each said row including a plurality of nozzle marks groups, each said nozzle marks group including nozzle marks associated with adjacent nozzles, each adjacent pair nozzle marks groups are spaced apart by a determined number of nozzles;
• acquiring an image of said combined nozzle pattern;
• detecting nozzle marks groups in each said combined pattern row of a respective combined color pattern in said combined pattern;
• and
• identifying and classifying malfunctioning nozzles according to the nozzle sampling period, the expected width of said nozzle marks groups, a nozzle locator and the density of each nozzle.