A dot or pixel is the smallest graphic element of any digital image. Each image contains a certain number of pixels, for instance 800 x 600 pixels. Changing the picture linear dimensions (resizing) results in the variation of the image quality (resolution). DPI (dots per inch) expresses the image resolution as the number of pixels (dots) per a linear inch. A higher DPI resolution corresponds to a better quality picture. Aim for at least 200 DPI resolution when printing your images.
Instructions
1. Click "Computer" or "My Computer" in the Windows Start menu to open the file manager (Windows Explorer).
2. Find an image file on your computer using Windows Explorer.
3. Use the mouse right button to click on the image and select "Properties." Then choose the tab "Details."
4. Read the image size in pixels, for example 2400 x 1600 pixels (width and height).
5. Decide on the size of the picture you need to print; for example, say you want a 6" x 4" picture.
6. Divide the width in pixels by the picture size in inches to calculate the horizontal DPI resolution. In our example, 2400 pixels / 6 inches = 400 DPI.
7. Divide the height in pixels by the picture size in inches to calculate the vertical DPI resolution. In our example, 1600 pixels / 4 inches = 400 DPI.
Tags: 1600 pixels, example 2400, inches calculate, number pixels, picture size, picture size inches, pixels inches