For an image sequence, background frame is first generated using the medium pixel values as background values;

对于一个序列，首先用像素点的中间值作为背景的像素值，生成背景帧；

youdao

In the end the whole video Mosaic is retrieved by superimposing the target region on the panorama background frame by frame.

最后逐帧将目标区域图像变换到背景图像上得到全景视频。

youdao

The frame at the far right has been compressed slightly to bring into view an intriguing interacting pair of background galaxies.

在画面最右侧的部分略微有所压缩，好让你能看到背景上引人注目的相互作用的一对星系。

youdao

By that I mean offer us a whole piece, with more detailed captions, full background notes and ideally quotes from those in the frame.

BBC: Drowning in pictures

Several background papers have been produced to guide six parallel sessions aiming to frame the context of adolescent girls and engage their participation in good practice, and discuss how to tackle outstanding challenges.

UNESCO: MEDIA SERVICES

Competitors shoot from the prone position at a paper or plastic target on a wooden frame, with a round, black aiming mark on a white background.

BBC: HOW FULL BORE EVENTS UNFOLD