Blurry faces in your photos can be caused by a number of things, including bad camera focus, a shaky camera or motion blur (the subject moved). With a graphics-design and photo-manipulation software program such as Adobe's Photoshop, Corel's Paint Shop Pro, Google's Picasa or the open-source GIMP, you can sharpen a blurred face and restore your photo.
Apply a sharpening filter. All photo-editing programs include a sharpening tool that works by increasing the contrast between pixels in your photo. Sharpening the photo will remove some of the blurriness, but it may also introduce graininess if the photo is over-sharpened.
Use an unsharp mask, if your program supports it, for more fine control over the sharpening process. While most sharpening filters will apply the same algorithm to every photo, programs that feature an unsharp mask will give you more control over the specific details and areas you want sharpened.
Choose the sharpen edges tool if your photo becomes too grainy before the blurred face can be restored. This tool will sharpen only the edges of your photograph, such as the transition between the face and the background and the lines between facial features. Because the sharpening will be limited to the edges, this method is less likely to introduce graininess or pixelated artefacts in other areas of the image.
Resize your photograph downward. Blur is often only noticeable when viewing the photo full-size. Physically resizing the image to smaller dimensions will help to hide the blurriness. The amount of shrinking you should apply depends on the degree of blur in the image, so try different sizes until you find one that is an acceptable size and sufficiently hides the blurriness.
Many of the popular photo-editing programs include plug-ins from third-party developers that are better able to take care of blurry photos. Look for plug-ins like Focus Magic, Pixel Genius and Photokit Sharpener.
Excessive blurriness is almost impossible to restore. The best way to get rid of blurred photos is to avoid it in the first place. When shooting, use a fast shutter speed to help reduce motion blur and camera shake, and focus directly on a person's face (even if you need to recompose the image afterward).