INSPECTION OF COLOUR PRINTING QUALITY

Autor: Juuso Äikäs, Raimo Launonen, Caj Södergård
Rok vydání: 1996
Předmět:
Zdroj: Scopus-Elsevier
Södergård, C, Launonen, R & Äikäs, J 1996, ' Inspection of colour printing quality ', International Journal of Pattern Recognition and Artificial Intelligence, vol. 10, no. 2, pp. 115-128 .
VTT Technical Research Centre of Finland-PURE
ISSN: 1793-6381
0218-0014
Popis: The use of machine vision technology is being investigated at VTT for improving the colour quality and productivity of web offset printing. The visual inspection of colour quality is performed by a colour CCD camera which traverses the moving web under a stroboscopic light. The measuring locations and goal values for the colour register, the ink density and the grey balance are automatically determined from the PostScript™ description of the digital page. A set of criteria is used to find the most suitable spots for the measurements. In addition to providing data for on-line control, the page analysis estimates the zone wise link consumption of the printing plates as a basis for presetting the ink feed. Target calorimetric CIE-values for grey balance and critical colours are determined from the image originals. The on-line measurement results and their derivations from the target values are displayed in an integrated manner. The paper gives test results of computation times, measurements of register error with and without test targets and the colour measuring capabilities of the system. The results show that machine vision can be used for on-line inspection of colour print quality. This makes it possible to upgrade older printing presses to produce a colour quality that is competitive with more modern presses.
Databáze: OpenAIRE