What does Dots Per Inch (DPI) and Pixels Per Inch (PPI) mean?
To skip the banner, Customer Care Area and the high level navigation area click here.Link to USGS home page. Banner Graphic a collage of images representing various USGS activities
USGS Home
Contact USGS
Site Map

Advanced Search

125 Years of Science for America - 1879 to 2004
About USGS  Our Science  Publications  Education  Newsroom
   

USGS Frequently Asked Questions

Question: What does Dots Per Inch (DPI) and Pixels Per Inch (PPI) mean?

Answer:

A dot per inch (dpi) and pixel per inch (ppi) is a measure of the sharpness on a display screen or printed image. The dot pitch determines the absolute limit of the possible dots per inch or pixel per inch. However, the display resolution of pixels that is set up for the display is usually not as fine as the dot pitch. The dots per inch and pixels per inch for a given picture resolution will differ based on the overall size of the image, since the same number of pixels are being spread out over a different space. The standard DPI for high resolution scanned aerial photogaphic products is 1200. The standard DPI for medium resolution scanned aerial photographic products is 600.

Source of this FAQ:
http://edc.usgs.gov/products/aerial.html

Return to list

  U.S. Department of the Interior

FAQ Home



List FAQ

Ask USGS

Format graphic contains no information