It is imperative to know the correct size of the picture you will be submitting to the passport authorities. Any other size may lead you to the rejection of the photo. Thus, follow the guidelines of your respective countries because every country has its own photo size.
In the United States, a passport photo has its own set of physical criteria in addition to the compositional requirements. The photo must be 2 inches by 2 inches (51mm by 51mm) in size and printed on matte or glossy photo-grade paper. It must also be devoid of flaws such as wrinkles, smudges, rips, and holes.
While altering a passport photo is not permitted, you can crop a photograph to fit the required dimensions. If you follow all of this advice, you should be able to get a passport photo that is absolutely acceptable.
In this way, you can change the size of the photo. But you have to keep in mind one thing here which is the picture quality. While altering the size of the photo, there are some instances that the quality of the picture is compromised. The picture appears blurry or pixelated.
Thus, even if you submit the correct size, your photo will be rejected on the basis of its quality. Consequently, you have to work that out as well. Always take your picture in a higher resolution so that even if you crop it, the picture quality will remain unchanged. ThePhotoApp can help to achieve the correct photo size.