Digital Zoom

Digital zoom is a software feature that supports the act of decreasing the visible view of a digital photographic image or video. Digital zoom can be achieved by cropping the image to a central perspective with the same original aspect ratio. When the user targets to zoom in an image with the use of cropping, the image can be brought back to its original pixel dimensions by zooming out.

Digital zoom can be performed electronically. There is no need to adjust the camera’s optics and no optical resolution is achieved by it.

Zoom is a feature present in numerous camera devices and mobile phone cameras. The purpose of this feature is to make a subject look closer by filling the image area more with the intended image subject.

Aside from the digital zoom, another type of a zooming feature is the optical zoom. When a user chooses optical zoom, lenses are moved to allow for better picture quality. The advantage of optical zoom over the digital zoom is that it does not have trade-offs in image size or quality which usually happens during digital zooming.

The two methods that define digital zoom are cropping and stretching.

A digital zoom performed with cropping does not characterize loss in image quality. The alteration that happens when the user crops the image is that it becomes smaller than its original maximum resolution. When a user crops an image, the same exact amount of detail is given off from an image such as that of the non-zoomed image with its full resolution.

A digital zoom performed with stretching results to an image with lesser image quality. Photos that are stretched appear blurrier as compared to a non-zoomed photo. The image size can reach the maximum resolution due to image stretching.

Some digital cameras entirely rely on the digital zoom feature because they are not built in with real zoom lenses. There are cameras that have real zoom lenses but switch to the digital zoom automatically when it has reached its longest focal length. Professional cameras do not have the digital zoom feature.