Application of digital photography technology in p

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Application of digital photography technology in printing


the content of image form is an important reproduction target in printing media. In the past, most of the images recorded by silver salt materials have to be converted from scanning to digital file form, and then integrated into a part of printed matter by typesetting operation. Recently, the technology of digital photography is becoming more and more mature, and the way of directly shooting electronic image originals is becoming more and more popular. The basic principle, operating characteristics, current situation of equipment, application practice and future direction are briefly introduced in this paper

basic principle

the process of digital image is not strange in the environment of digital printing, because the image processing software like Adobe Photoshop has almost become one of the standards of prepress operation, but there are some similarities and differences in the basic concepts of using scanner to obtain image or using digital camera, which need to be explained in advance

digital cameras, like scanners, project images onto photoelectric sensing components through the focusing of optical lenses to form image pixel units. However, the light source of the scanner is fixed, and the scanned object is roughly in the form of a plane; The object photographed by the digital camera can be in the form of three-dimensional, and the field light source intensity and color temperature characteristics can be changed. It is relatively complex, so we should pay special attention to it in use

compared with the production process, when using film to record images to print prints, there will be varying degrees of signal loss in the three stages of film exposure, chemical development and film scanning; The digital camera directly captures and generates electronic files, and the process has only one loss! Therefore, in terms of signal distortion rate, direct photography by digital camera can not only have better image quality, but also shoot and see at the same time, so as to improve the timeliness

however, the image quality obtained by digital cameras may not be better than that obtained by negative scanning. There are many reasons, such as lens optical quality, CCD quality, software ability or cost-effectiveness, etc. but in principle, the wedge-shaped mouth produces plastic deformation and severe valgus analysis, which has considerable room for improvement and high potential

operating characteristics

generally, when operating the scanner, the size between the original and the copied product will be used as the calculation basis of magnification, so it is not necessary to distinguish the difference between pixel and dot, but pay special attention to this relationship when taking images with digital cameras

pixel is generally the analysis unit when the input device samples the image light source. For example, the overall sampling capacity of digital camera is in pixel. Particle is each imaging entity unit that can be controlled by hardware equipment. For example, the printer takes the control ability of ink dots in unit inch as the unit of measurement (DPI) of its resolution, and the laser film output machine also takes how many DPI can simulate how many printing lines as the standard

in use, the general principle is to deduce the size that can be presented by the input image file from the resolution of the output device. For example, for 150 lines of printed matter, the pixel amount of the digital camera will be inverted with a resolution of 300dpi to calculate the printable size. If 6 million pixels (3000 pixels) × 2000), you can print out 10 × 6.6 inch image size. The conversion principle is defined by the relative presentation size of fixed file size under different resolutions, that is, the principle proposed by the author that the conservation of data can not do the law of regional connection. In practice, it still involves the characteristics of image quality coefficient and so on, which is more complex. Interested readers can read my book "digital photography technology" in detail, or please refer to the reference station

current situation of equipment, the speed of digital camera innovation is amazing, and the price adjustment also attracts eager photography lovers, but there are several phenomena that should be paid special attention to. It is generally believed that the higher the pixel, the better the image quality. In fact, it is not, because the resolution can be divided into optical resolution and electronic resolution. The latter is obtained from the former through mathematical operation and is a virtual number. Under the same optical resolution, the quality of the actual image is the real focus, which involves the quality of the lens. Its unit is the quality of joules, the amount of photoreceptor noise and software processing ability. It is quite complex, but the best way is to take actual photos for comparison

the current digital cameras are roughly divided into three levels, ranging from tens of thousands of yuan, hundreds of thousands of yuan to nearly one million yuan. In the range of tens of thousands of yuan, the common fool digital camera is more than enough as a daily photo or page photo. Recently, the interchangeable lens digital camera developed by the old monocular camera system is the favorite of professional photographers. Because the old lens and other equipment are compatible with its system, the monocular camera has all the mobility and rich control functions. It is almost the same as using the original advanced monocular camera. The only drawback is that it still has the problem of lens magnification. It is very painful to shoot at a wide angle, but the improved model will be available soon! The system equipped with a large camera and a digital back is a sharp weapon for commercial photography. Because its file is large, it can control the perspective angle such as pitch, but the price is nearly one million, and the economic threshold is high

application practice

it has been 20 years since the first generation of digital cameras. Digital cameras can be seen everywhere in the streets. There are also professional applications in mail order catalogue and wedding photography in China. Almost every person has a digital camera, but does it mean that the image quality is improved at the same time

in the previous printing process, the physical photos and slides in the standard environment can be used as the basis for the photographer to conduct layout and communicate with prepress operators. However, in the process of digital photography, only the actual image files are used as the originals for communication and production, but each computer screen has its color characteristics, so the images presented will fall, Therefore, digital proofing or color management system has become an important cooperation project. At the same time, in the past, photographers only operated cameras, but now they also need to operate computer equipment. These additional technical costs and capacity requirements are not very explicit factors, so we should pay special attention to them in application

future prospects

the timeliness and convenience of digital photography are its irreplaceable advantages, but at this stage, its image quality and economic benefits are still improving rapidly. With the large investment of Taiwan's electronic industry, new digital cameras will become as popular as scanners. For the printing industry, the image generated by digital photography will become a very common type of manuscript in the future. When this trend comes, how to adjust the printing process and learn its technology will be the focus worthy of investment

source: ca800 search


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