A NEW IMAGE ANALYZER FOR THE CHARACTERIZA TION OF PRINT QUALITY AND CALENDER BLACKENING

The commonly subjectively assessed quality of rotogravure and offset p rints can be characterized by means of a recently developed printabili ty tester The objective values obtained by this image analyser correla te well with the visual ranking of observers. Beside other parameters the number of missing dots per unit of area, the contrast between prin ted areas and their unprinted surrounding and the sharpness of halfton e prints can be measured. Unwanted laterally reflectance in intended h omogeneous solid prints is characterized by a mottling index. Furtherm ore, the intensity of calender blackening of unprinted super-calendere d papers can be determined. The presented findings demonstrate the pos sibilities of this low cost image analyser, which is suitable for the application in quality assurance, product optimization, research and d evelopment.