The best effect of the hottest display manuscript

The best effect of displaying originals: resolution analysis of prepress equipment (Part 1)

I. scanners

most scanners sold on the market at present have the function of software and hardware expansion of resolution. Some scanner ads only say 9600 × 9600dpi, which is only the maximum resolution obtained by software interpolation, is not the real optical resolution of the scanner. So for the scanner, its resolution includes optical resolution (or optical resolution) and maximum resolution

we say that the resolution of a scanner is as high as 4800dpi (this 4800dpi is the sum of optical resolution and software difference processing), which means that 4800 can be collected on the scanning format of 1inch2 when inputting images with the scanner × 4800Pixel。 For a scanning area of 1inch2 square, the size of the image generated after scanning with a resolution of 4800dpi is 4800 × 4800Pixel。 When scanning images, the higher the scanning resolution is set, the finer the generated images will be, and the more image files will be generated. The team leader is Ma Kai, vice premier of the State Council

II. Printer

we say that the resolution of a printer is 360dpi, which means that when using the printer to output images, 360 color dots representing the image output effect can be printed on each inch of printing paper. The larger the number indicating the printer resolution, the smaller the color dots representing the image output effect, and the finer the output image

for images with a fixed file size, the larger the printer resolution, the smaller the size of the printed image. The size of the printer's color dot is only related to the hardware technology of the printer, and has nothing to do with the resolution of the image to be output

III. display

we say that the resolution of a certain brand of display is 80dpi, which means that within the effective display range of the display, the display device of the display can produce 80 light spots per inch of fluorescent screen. For example, for a 14inch display (the diagonal length of the fluorescent screen is 14inch), and its point distance is o.28mm, then: the resolution of the display =25.3995mm/inch ÷ 0.28mm/dot=90dpi (1 inch=25.3995mm)

generally, the DPI value representing the resolution of the display is not marked when the display is delivered from the factory, and only the point distance is given. We can calculate the resolution of the display according to the above formula. According to the DPI value we calculated, we can then calculate the maximum display mode that the display can support. Assuming that the diagonal length of the effective display range of the fluorescent screen of the 14inch display is 11.5inch, because the display ratio of the horizontal and vertical directions of the display is 4:3, it can be set that the horizontal width of the effective display range is 4inch and the vertical height is 3xinch. According to the Pythagorean theorem in mathematics, x=11.5 ÷ 5=2.3inch can be obtained. Therefore, the effective display range width is 2.3 × 4= 9.2inch, vertical height is 2.3 x 3=6.8inch. The maximum display mode is about 800 (9.2 × 90) × 600(6.8 × 90), in this case, a dot is used to represent a pixel

the above mainly describes the device resolution of scanners, printers and monitors. Strictly speaking, the device resolution and the resolution of the image processed by the device are two concepts that are both related and different. The resolution of equipment is determined by the production process of hardware equipment. Although the resolution of some equipment with quality problems can be adjusted by software, they all have a very limited maximum resolution, and users cannot make any breakthrough in it

when describing and understanding the device resolution. We must rely on the resolution of the image it processes. Image resolution is a measure of the fineness of the image itself. For images processed by scanners and printers, the resolution is measured by the number of pixels per inch (PPI). The resolution of an image used for computer video processing is expressed by the number of pixels that can be displayed in the horizontal and vertical directions, such as 800 × 600、640 × 480, etc. whether the image itself is fine is only related to the resolution of the image itself, and has nothing to do with the resolution of the hardware device processing it, but whether the image processing result is fine is directly related to the resolution of the device processing it

resolution of the digital camera

the resolution of the digital camera determines the size of the final high-quality picture that can be printed from the captured image, or the size of the picture that can be displayed on the computer monitor. The resolution of a digital camera depends on the number of pixels on the CCD (charge coupled device) chip in the camera. The more pixels, the higher the resolution. It can be seen that the resolution of a digital camera is also determined by its production process, which is fixed at the factory. Users can only choose digital cameras with different resolutions, but cannot adjust the resolution of a digital camera. For similar digital cameras, the higher the resolution is, the higher the grade of the camera is. However, the data file generated by the high-resolution camera is large, which has higher requirements for the speed of the processing computer, the capacity of memory and hard disk, and the corresponding software

the pixel level of the digital camera and the final size of the photos that can be printed with a certain resolution can be simply calculated by the following methods: if the resolution of the color printer is NDPI, the horizontal pixel of the digital camera is m, and the maximum printable photos are m ÷ n inches. For example, if the resolution of the printer is 300dpi and the horizontal pixel is 3600, the maximum photo size that can be printed without interpolation is 12inch (3600 ÷ 300). Obviously, the larger the size of the digital photos to be printed, the higher the pixel level of the digital camera is required. The method of calculating the display size is the same as that of printing size

resolution in the printing field

in the printing field, the resolution is expressed by the number of lines arranged at equal distance per inch, that is, LPI (lines per inch). In the process of traditional printing and plate making, when making plates, it is necessary to add a screen in front of the original image. The average value of the experiment must be done for five consecutive times. This screen is composed of lines with the same transparent and opaque parts in a square shape. These lines, also known as gratings, are used to cut light anatomical images. Because the light has the physical characteristics of diffraction, after the light passes through the line, it forms points with different sizes that reflect the changes of the original image by stepping back and strengthening environmental protection. These points are halftone points. A halftone point will not exceed the area of a grid at most. The more lines, the more layers of the image, and the better the image quality. Therefore, LPI representation resolution is adopted in the commercial printing industry

(to be continued)