Things You'll Need
Image editing program like Microsoft Paint
If you have a hard copy print of a photograph that you would like to enlarge for reprinting at a larger size, follow these steps to scale it up to a bigger image. You will need to have access to a flatbed scanner that is connected to a computer and an image editing software program. Read on to learn how to scan and enlarge a photo.
Place your document on the scanner and close the lid. Before you scan, look for the button that says "Scan Settings." Most scanners will have this feature in the user interface. Refer to the picture here, and look for a similar selection for your scanner. Select "JPEG Image" as the file type.
Select a scan resolution setting of 600 ppi as shown here. (The higher the number, the more detailed your scan will be. The size of the file also increases with a higher setting, as does the time it will take to complete the scan.) Know that 600 ppi is an optimal setting for the average size photo print. Keep in mind that ppi stands for pixels per inch.
Scan your photograph and save it to a folder or onto the desktop. Check to make sure you know where the scan was saved to. If you don't "Browse" and select a folder, the scanner may place it automatically.
Open an image editing program on your computer. Most computers have a program, like Microsoft Paint as shown here, already installed on them. Open your scanned image in the program. If you don't have a paint program, you can download a free one from the link in the Resources section below.
Select "Image" from the menu bar at top, then "Stretch and Skew," as shown here. The “Stretch” function will allow you to scale the image up to a larger size. If you increase the values for both height and width by the same percentage, the image will enlarge proportionately.
Increase the size of your image by typing in a higher percentage in the boxes for height and width as pictured here. In this example, the percentages were each were raised from the default setting of 100 percent to 200 percent. The resulting image in this case is four times as large.
Save the enlarged image file with a new name. Your original scan will still be available for re-use. Consider using glossy photo paper that will work with a desktop printer. Another way to have photo-quality prints is to take the image file saved on disk or thumb drive to a print shop, like Kinkos.