Why Does My Photo Become Blurry When I Enlarge It?

By Angela Tague

Low-resolution digital images appear blurry when enlarged.
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As an increasing number of electronic devices include digital cameras, the levels of digital imaging quality become more apparent. Although snapshots look fine on the screen of a cellphone or hand-held gaming system, the lack of image detail becomes noticeable when you enlarge the picture. Low-resolution images -- from a digital camera or camera feature on an electronic device -- will look blurry when enlarged.

Blurry Pixels

Digital images are composed of pixels. Think of pixels, or picture elements, as tiny dots of paint on a canvas. The more dots of paint -- or pixels -- the more detail you see in the picture. When you enlarge a digital image and it begins to look blurry, the pixels get stretched too much to accommodate the larger dimensions, and the sharp borders in the picture appear distorted.

Compression and Clarity

Photos can also appear blurry when recorded with high compression. When a digital camera stores an image, it eliminates and compresses some of the duplicate data to fit more pictures in the given amount of storage space. Instead of your camera remembering 5,000 pixels of a specific shade of blue in a picture of ocean waves, it remembers the color once and replicates it 4,999 times when the image gets opened later. If your camera discards too much data during the compression process, the replicated pixels can appear blurry when enlarging a picture.

Camera Settings

To avoid blurry photos when you plan to enlarge a picture, change your camera settings before shooting. Choose the highest resolution available to use all the available pixels on the digital camera's sensor when capturing the photo. But remember, a camera with an 8 megapixel rating will create a sharper enlargement than a cellphone camera with a 2 megapixel rating -- simply because there's more data collected. One megapixel equals one million pixels.

Set the camera to a low compression. Although you won't fit as many photos on your memory card or internal storage, your image quality will look better when you enlarge the picture. You want the camera to retain as much of the original imaging data as possible to produce a clear, sharp photo.

Enlarging Tips

If you've already taken the photo, changing the resolution and compression options on your camera won't affect the image. To alter the image size, use computer photo editing software that offers a process called "interpolation." This procedure actually grows the resolution of your picture by creating pixels to enhance the detailed portions of the image.

If you try to enlarge a photo by using the resize option on photo editing software, the program will duplicate the pixels in a pattern across the entire photo, leaving the image appearing boxy and blurry.