Also, within software you have more control of what you will resample. That said, sometimes when upscaling (increasing the sample rate), a fusion of resampling and some interpolation may occur as there will be potential gaps (aliasing) in the pixels. As stated, software does this based on the information that already exists within the image, and this is why it is better. Increasing the sample rate enlarges the physical appearance of the image and decreasing the sample rate reduces the physical appearance of the image. Because of this, resampling creates more pixels with the data within the existing image (instead of fabricating it as in interpolation). Higher resolution images have more samples (pixels). Resampling implies changing the sample rate within an image, the pixel frequency is the data that is sampled. Software zoom uses resampling to do a similar thing but often has more sophisticated algorithms and tends to upscale the image much better than digital zoom. All you can do is enlarge everything at once and not focus on a specific part of the image. Another problem is that digital zoom interpolates the entire picture. Interpolation creates an illusion of increased detail, but cannot create detail that was never there in the first place. ![]() ![]() Below is a brief discussion of software zoom versus a camera’s digital zoom and how they work, followed by a how-to on doing this in iMovie and Final Cut Pro X (FCPX).ĭigital zoom on any device uses interpolation to make the image larger (upscaling) by calculating values between sample points and adding pixels (data) to the image. This will achieve a “zoom” effect on whatever part of the video clip you isolate and crop to. The technique I would like to talk about is cropping (removing part of the image to alter the framing, create a direct line of sight to a desired subject matter, and sometimes to change the aspect ratio of an image). What if you have an existing video that you need to zoom in on? After it has been captured, the only way is through digital manipulation of the image after the fact. If you’ve ever wondered why those digital camera, iPad, and iPhone photos look so pixelated after zooming in, this is why. Your zoom amount is limited only by the size of the digital zoom, but in turn you don’t get the quality of optical zoom. The more powerful the lens, the more you can zoom the smaller the lens, the less you can zoom.ĭigital zoom, on the other hand, alters the actual image and attempts to go beyond the limitations of the physical lens. This is because what it can enlarge has its limits based on the physical limitations of the lens. ![]() Optical zoom uses the physical lens of a camera and tends to be preferred by professionals. This is because the iPad (and iPhone) use digital zoom and not optical zoom. In my iPad post regarding video creation on the iPad, I hinted at using software to zoom instead of using the digital zoom available on the iPad.
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