Most people heard the term DPI. 메이저사이트 In most cases the term is used in the wrong context to express the number of pixels in a photo, the number of dots in a print or the maximum dots per inch a printer can output. A relatively new term PPI was introduced in order to resolve this wrong usage of the term DPI. In this article we will try to explain in simple words what is DPI and what is PPI and should each be used.
PPI: stands for Pixels per Inch. PPI describes the number of pixels per inch in a photo. PPI is a function of the number of pixels the cameras sensor supports (also known as megapixels) and the size of the photo. To calculate a photos PPI simply multiply the page length by its width in inches. The result is the number of square inches on the page. Now divide the number of pixels the sensor supports by the number of square inches. The result is the number of pixels per square inch. All that is left to do is to find the square root of this number. Following is a table that shows the PPI for various page sizes for a 5 megapixel camera.
page size 4X6 – 456 PPI
page size 5X7 – 377 PPI
page size 8X10 – 250 PPI