What does 300dpi mean?

300dpi refers to 300 pixel units in an area of ​​one inch; dpi refers to the number of pixels in a unit area, which is the scanning accuracy; currently, pixels in an area of ​​​​an inch are calculated internationally. How much, the smaller the dpi, the lower the resolution of the scan. Due to the influence of network transmission speed, the pictures used on the web are all 72dpi.

The operating environment of this article: Windows 7 system, DELL G3 computer.

dpi refers to the number of pixels per unit area, which is the scanning accuracy.

Currently, the international community calculates the number of pixels in an area of ​​one inch. The smaller the dpi, the lower the scanned resolution. Due to the influence of network transmission speed, the pictures used on the web are all 72dpi, but this parameter cannot be used for developing photos, it must be 300dpi or higher 350dpi. For example, if you want to develop a 4*6-inch photo, the scanning accuracy must be 300, then the file size should be (4*300)*(6*300)=1200 pixels*1800 pixels.

Extended information:

DPI is originally a unit of measurement in printing, which means the number of dots that can be printed per inch (Dot Per Inch) ). However, with the rapid development of digital input and output devices, most people also express the resolution of digital images in DPI, but more rigorous people may notice that the dots (Dot) calculated during printing and the display pixels of the computer monitor ( Pixel) are not the same, so more professional people will use PPI (Pixel Per Inch) to express the resolution of digital images to distinguish the two.

We usually talk about the DPI of the printer resolution, which refers to the "theoretical number of ink dots" that can be printed per inch under the highest resolution mode of the printer.

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