Digital pictures measure resolution in dots per inch.
When you take a digital picture, the picture is composed of many little dots, or pixels, of color that, when put together, make up the final image. The density of these pixels on a picture is known as dots per inch (DPI). When you have a picture, to know the dimensions in pixels, you can convert from inches if you know the DPI and the dimensions. The higher the DPI, the higher the resolution, but the smaller the image.
Instructions
1. Measure the dimensions of the picture in inches.
2. Multiply the length in inches by the DPI to find the length in pixels. For example, if the photo's length equals six inches and the resolution is 100 DPI, multiply 6 by 100 to find the length is 600 pixels.
3. Multiply the width in inches by the DPI to find the width in pixels. For example, if the photo's width equals four inches and the resolution is 100 DPI, multiply 4 by 100 to find the width is 400 pixels.
