What are DPI (Dots per Inch) and PPI (Pixels per Inch)?
Degree of resolution of print, or screen images expressed in terms of the number of printed dots or pixels per linear inch. The higher the dpi, the greater the level of image clarity and sharpness achieved. Most home computer scanners and laser printers produce 300 dpi images. Higher resolution images take up more memory, take longer to scan, and are not necessary for most home applications. Commercial applications require higher resolution images of 600 to 1200 dpi. Pixels per inch (PPI) or pixel density is a measurement of the resolution of a computer display, related to the size of the display in inches and the total number of pixels in the horizontal and vertical directions. This measurement is often referred to as dots per inch, though that measurement more accurately refers to the resolution of a computer printer. PPI may also be used to describe the resolution of an image scanner or digital camera; in this context, it is synonymous with samples per inch.
