| Print quality detection system based on whole page mainly achieved dot percentage detection, chromaticity detection, ink detection, print pressure detection and color sequence detection. Based on previous studies, this project is mainly for dot percentage detection of print quality detection system based on whole page.After the analysis of dot percentage detection based on Neugebauer equations, this project proposed a new dot percentage detection method-statistics and identification method of pixels. Statistic and identification of pixels is based on digital image processing. Every pixel of print dot image is classified and added up. Color characteristic value of each pixel of the digital image is considered as pattern feature in order to identify the different color elements and then detect dot percentage. From the microscopic point of view, the print is composed of the color elements of different colors. The four-color print can be printed in24kinds of color sequences. Considering the impact of the color sequences, there are65kinds of color elements in the four-color print. The print was scanned with high-resolution CCD, and the pixel is smaller than the dot. The color of each pixel can be classified as a certain color element. Color lumps of65kinds of color elements are scaned in order to establish65kinds of basic color modes. After the print is scaned, the print dot image is zoned according to ink zone.In each ink zone, Color characteristic value of each pixel is identified by the identification function.Then the color of each pixel can be classified as a certain color element. According to the pixel statistics of every color element, the number of C, M, Y, K pixels can be calculated. At last, the calculation of dot percentage is realized. At the same time, the color sequence of the print can be detected. This project tries to detect the color sequence of the print using probability and statistics method.Microsoft Visual C++is applied to programme. The method of dot percentage detection and color sequence detection from the theoretical analysis is written into a computer program.Then the program is placed in print quality detection system based on whole page. |
