Automatic colour printing inspection by image processing

An Experimental Machine Vision System for Quality Control of Industrial Colour Printer

“…The inspection of color printing products constitutes a very important quality control (QC) task in the printing industry [1]. Quality control of the industrial color printer is still based on the judgment of human operators, while most of the other manufacturing activities are automated [11].…”

“…While this kind of inspection is flexible, it is tedious and leads to unstable and irreproducible results [2]. The results of inspection are not reliable as they vary with mood, time, experience and personal skills of the inspectors [1]. Although humans can do the job better than machines in many cases, they are slower than the machines and get tired quickly.…”

“…The color registration defects result from displacements of basic printing color planes, caused by mechanical problems and set-up errors on the production line. The color purity defects result from color variations due to the impurity of primary colors, which are caused by errors on the quantity/quality of ink of the basic colors supplied to the printing heads [1]. This paper proposes automating color printing inspection using an image processing system with mathematical and statistical techniques, which correct the errors of printing caused by movements of color trundles in the process of printing.…”

Computer-aided visual inspection of surface defects in ceramic capacitor chips

“…Inspection of surface defects has become a critical task for manufacturers who strive to improve product quality and production efficiency [1,2]. Surface defects can affect not only the appearances of products but also their functionality, stability, safety, etc.…”

Image Analysis and Fuzzy Integration Applied to Print Quality Assessment

“…Using simple print features characterizing noise level, edge sharpness, and tonal contrast the system is trained to categorize prints into the ''bad quality'' and ''good quality'' classes. Another approach to categorization of prints into the two classes was proposed by Luo and Zhang (2003). The categorization is based on moment invariants computed from a color image histogram.…”