Pre-press production process troubleshooting

1 What are the main types of input devices?

1. Digitizer 2, color scanner (platform and drum type) 3, electronic color separation machine 4, video camera, video recorder and television receiver 5, electronic digital camera

2 What is the difference and connection between DPI and LPI ?

DPI is the inch number used to represent the processing accuracy of the image processing system. It is one of the units for measuring the resolution of the image. Generally, 2*2 pixels or more corresponds to 1 dot, that is, the number of LPI screen lines is the number of lines. About one-half of the DPI number; scanning spots constitute a network, that is, the number of DPI must be greater than the LPI number of 10 to 20 times.

3 What is a pixel? Resolution?

Pixels are the smallest unit that describes the image in a lattice. Although the pixel is the smallest unit describing the bitmap image, it has a fixed shape but does not have a fixed size. Resolution, representing an image processing device, to represent the fineness of images, prints.

4 What is color management? What are the contents of color management?

There is an interoperable problem between different software or hardware, how to obtain the expected consistent color under a variety of configuration possibilities, that is, study device-independent color representation, and the conversion of color representation for a specific output device. . There are three major aspects of color management: corrections, features, and transformations.

5 What is computer direct imaging printing?

Direct-imaging printing is a new type of computer typography printing technology. When coloring this kind of new technology, it does not require the traditional printing process of outputting the film and then the process of making the PS version from the film. The color desktop publishing system is used to edit graphics, photos, texts, and texts. After the image is processed, the image is directly presented on the printing plate for printing. The printing method achieves 1016 DPI resolution with up to 175 lines per inch quality color print.

6 What is an open system?

Can accept any Chinese system input file, can be output to any English software for processing, the results can be sent to any kind of output device such as: electronic color machine, laser printer, laser imagesetter, computer It can also be output as a PS file, and can be exported to any output center in the world to output four-color CMYK color separation films. This is the concept of full openness. The Postscript language is the foundation.

7What is the role of PostScript? What are the characteristics?

PostScript language is an interface language output from the desktop system to the layout device. It is specially designed to describe images and text. A variety of desktop software systems work together and must rely on a certain format to exchange information with each other. This is the Postscript language. The function is to record the image text on the page with a digital formula and run it on a computer. Finally, it is translated into a desired output by a Postscript decoder, such as being displayed on a screen or output on a printer or an imagesetter. The Postscript file is just a text-based file that can be used on different computer workstations such as MAC, PC, NEXT, SUN, etc. Features: Ability to comprehensively process text and images; foundation for open desktop publishing systems: With the Postscript standard data format, data exchange is possible between general-purpose computers produced by different manufacturers and various special-purpose computer systems; The dependence of layout production on the use of equipment.

8 What is the workflow of the color publishing system?

1) Text entry: Enter the text into the computer.

2) Scanning the image: The image is digitized and entered into the computer.

3) Group Edition: After editing and modifying the text and images on the computer, the text and images will be mixed, and the results will be printed out proof proofs.

4) Separation exposure: After raster image processor is used to describe the page description language of the layout into a bitmap image, the dot matrix image is sent to the laser imagesetter to control the sensitivity of the film.

5) Rinse: After the film is sensitized, use the punching machine (developer) to flush the color separation film out of the four-color film.
6) Print Proofing: Provide proofs and proofs for printing reference.

7) Finish color prepress processing. If the material used for separation in the fourth step is PS (pre-sensitized plate), this workflow is called CTP.

(to be continued)