Can I get high resolution photo from video?

Question

Waiting for the exact moment to snap a picture can be very difficult especially when working with children or animals. I've read somewhere (can't find source) that every freeze frame from an HD video is essentially a high-resolution photo (is this even true?).

What are the challenges, pros, and cons of selecting the best frame from a video as a way of taking still photos where timing is crucial?

Answer

The big pro to this is, as you say, the ability to take many pictures in a short period of time, allowing you to pick the best frame.

However, there are several cons to this approach:

• Lower resolution. Even "Full High Def", 1080p, is only 2 megapixel (1920 * 1080 = 2,073,600). This would give you an acceptable print size of 6.4x3.6 inches, at 300 DPI. This might be fine for you, but if you want a larger print, you'll start noticing pixellation.
• Often, less control of settings like shutter speed, ISO, and aperture. Video also can generally deal with a bit more motion blur than still photos, and the camera may allow the shutter speed to drag longer than you might want.
• Video compression artifacts. Aside from key frames, most frames in a compressed video are rendered by modifying a prior frame. This results in artifacts that may not be noticeable in a video, but will degrade the quality of your photo. This depends a lot on the codec and the bitrate of the video.

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