Research On Map FM Screening Model And Its Reproduction Characteristic In Printing

Digital screening is one of the key techniques in map printing. It is a vital way to producebinary images. According to the differences in screening mode, digital screening can be dividedinto three groups, amplitude modulation screening (AM), frequency modulation screening (FM)and hybrid screening. With the development of technology and people’s advancing requirementon products quality, some flaws in inherited screening arithmetic gradually emerge, whichstimulates the constant appearance of new screening arithmetic. The maturity of four colorprinting technique makes the replacement of spot color printing by four color printing into being.Map printing widely uses amplitude modulation screening, which can produce qualified maps tomeet users’ needs. However, as a traditional way of screening, amplitude modulation screeningcannot avoid some inherited flaws such as jagged outlines, moiré and low color expressive forceetc. In producing high precision maps, Hi-Fi Color maps and high quality maps, amplitudemodulation screening is incapable. The appearance of frequency modulation screening solvesthese problems and it is successfully used in common products’ printing. Nowadays, mapfrequency modulation printing isn’t researched and practiced. This paper focuses on frequencymodulation screening technique. It studies the theory and technique of map frequencymodulation printing, which concludes the following contents:1. It expatiates on the background and significance, and analyzes the status quo of mapfrequency modulation printing. It also explains the contents, research thoughts and structure.2. From the aspect of qualitative nature, it illustrates the screening model and itsreproduction characteristic in map printing. It analyzes the AM and FM’s screen dots generationprinciples as well as their advantages and disadvantages, and then analyzes their application inmap printing from the aspect of theory. It compares each model’s characteristics and bringsforward the thought of map FM printing.3. On the basis of FM screening, it confirms the optimal model and parameter in map FMscreening. It firstly analyzes the basic principle of the two dithering algorithmic. By developing“FM screening software on dithering algorithmic”, it carries out experiment to research themodels on line graphics and image maps, which confirms the optimal model and parameter. Itresearches the application of multiplicative congruence pseudo-random algorithmic on mapscreening, especially researches on the screening efficiency and then confirms the optimal modeland parameter.4. It studies the reproduction characteristic of map FM screening. Based on the dot gainprinciple, it fits AM and FM dot gain curves, and brings forward the quality control conditions ofmap FM printing. It studies the plate linearization method and dot gain compensation method. By making color scale and surveying data, it quantitatively fits the plate linearization curves, dotgain curves and dot gain compensation curves and concludes the reproduction characteristic aswell as law of map FM printing.5. In the aspect of map FM printing color, from the point of replacement of spot colorprinting by four color printing, in order to get CMYK color to match the standard color, thispaper carries out invariant scale experiment to research on seven commonly used printing color.It uses objective evaluation and subjective evaluation to evaluate each index of the printing proofand get the conclusion that map FM printing is better than map AM printing.6. On the basis of analyzing AM and FM models’ flaws, this paper develops second orderarithmetic model based on multiplicative congruence pseudo-random algorithmic, and carries outexperiment to validate that this advanced arithmetic model is feasible and valuable.