What is PPI? Easily explained
What is PPI? There's a lot to hide behind the three letters. You can find out what the abbreviation PPI means in photography and image processing in this article.
PPI: The meaning in the image display
In photography and image processing, the abbreviation PPI stands for Pixels Per Inch. Translated into German, the abbreviation PPI means pixels per inch.
- Accordingly, PPI is a measure that defines the relative resolution of images by points. This means the resolution of an image that was printed in a certain size.
- The American unit of length inch serves as a template for the unit of measurement. One inch is approximately 2.54 centimeters.
- Accordingly, the higher the PPI number, the finer the display of the respective picture.
- The term DPI is also very often heard or read in this context. The difference between DPI and PPI is not very big, but of course there are deviations.
Calculation of PPI
As an example, let's imagine a digital photo with a resolution of 1, 000 to 2, 000 pixels.
- We would now like to print this in size 10 to 20 centimeters, which is the equivalent of 3.94 to 7.87 inches.
- The relative resolution is obtained by dividing the pixel values by the corresponding inch values, i.e. 1, 000 pixels divided by 3.94 inches and 2, 000 pixels by 7.87 inches.
- Both calculations rounded up to 254 pixels per inch, which is 254 PPI, which is the relative resolution.
- So the smaller you print an image, the higher the pixel density.