Things You'll Need
Instructions
Enlarge a Photo in Photoshop
Open the photo in your Photoshop program.
Click the Image drop-down menu and select "Image Size."
Select "Constrain Proportions" once the Image dialogue box opens.
Adjust the width or height in either pixels or inches.
Click "OK."
Enlarge a Photo in Windows Live Photo Gallery
Click on the photo you want to resize in Windows Live Photo Gallery.
Open the File drop-down menu.
Select "Resize."
Select a new size for the photo in the Resize dialogue box.
Click the "Resize" and "Save" button.
Enlarge a Photo in iPhoto
Open iPhoto program and select the desired photo while in "Organize" view.
Open the "Share" drop-down menu and click "Export" for iPhoto 5, or open the "File" drop-down menu and click "Export" in iPhoto 4 and 6.
Select "Scale" in the Export Photos box.
Enter your desired size in pixels.
Click "Export."