You must provide two photos for your passport.
To obtain a United States passport, you must present several pieces of information. This includes an application, evidence of citizenship, identification, a fee and two identical color photos. These photos must meet the requirements of the Bureau of Consular Affairs.
Obtaining a Photo
You can have a passport photo taken by a professional photographer, or you can take one on your own with a digital camera. If you take your own photos, you must have a high-quality color printer capable of printing photos that meet the Bureau of Consular Affairs' standards. The BCA recommends transferring your digital images to a disk and having them printed by a professional photo lab. Vending machines photos are not acceptable.
Measurements
The Bureau of Consular Affairs states that all passport photos must measure 2 -by-2 inches. The size of your face in the photo should be between 1 inch and 1 3/8s of an inch. This measurement should be from the top of your head, including your hair, to the bottom of your chin. Digital photos should have a resolution of at least 3 mega-pixels.
Other Requirements
Passport photos must meet certain quality standards. The Bureau of Consular Affairs requires photos to be clear, in color, focused and free of shadows on the face. You should be looking directly into the camera. The photo should be neither over-exposed nor too dark. No pixelation should be visible.The background should be plain and white. Do not wear a uniform, but do wear glasses or a hearing aid if they are part of your normal attire.