The new iPhone models can record and play videos in 4K. If you want to extract a frame from a high-resolution video on your iPhone, your best bet is to take a screenshot of it or to transfer it to your desktop and use a powerful desktop video editor for the job. If you take a screenshot fo the video on your iPhone, it won’t be in 4K. It will be the same resolution as all the other screenshots on your phone so, if you want to extract high resolution frames from 4K videos on iOS, use Frame Grabber.
Frame Grabber is a free, open-source app for iOS that was built for this very purpose. You can get it from the App Store.
Open Frame Grabber and select the video you want to extract a frame from. 4K videos can have one of two resolutions; 4096 x 2160, or 3840 x 2160. You can tap the ‘i’ button to view the resolution of the video you’ve selected to be sure you have the right one. Play it to the frame you want to extract, and tap the share button.
In the menu that opens, select the Save image option. This image will be in full 4K resolution. To check the resolution, you need to examine its EXIF data. The resolution of the photo should match the resolution of the video.
Frame Grabber isn’t exclusively for 4K images. You can use it for any video in your camera roll, regardless of the resolution it was recorded in. If you need to extract a frame from a video on iOS, and have it match the quality of the original video this app is the way to go. Screenshots will never be able to do the video justice. The only alternative is to take photos while you’re recording a video. You can do this by tapping the capture button next to the record button in the camera app. These screenshots match the resolution of the video and are of high quality.
The only problem with capturing photos this way is that it can be difficult to do so while you’re recording a video. The photo may also not be taken at the right moment and you might still need to extract a frame from the video itself.
Frames from a video can be extracted in full resolution from a desktop; there’s no shortage of apps that can do the job but if you’re on an iPhone or iPad, your options are limited and using a complex video editing app like iMovie on a small device like an iPhone isn’t exactly intuitive.
