1
00:00:00,560 --> 00:00:03,600
Speaker 1: Welcome to brain Stuff from how stuff works dot com

2
00:00:03,600 --> 00:00:08,440
Speaker 1: where smart Happens. Hi and Marshall brain with today's question,

3
00:00:08,840 --> 00:00:12,360
Speaker 1: how do they superimpose the first down line onto the

4
00:00:12,400 --> 00:00:15,880
Speaker 1: field on televised football games? This is one of those

5
00:00:15,920 --> 00:00:19,120
Speaker 1: things that sounds really simple in theory, but it ends

6
00:00:19,200 --> 00:00:22,520
Speaker 1: up being incredibly complicated when you actually try to do it.

7
00:00:22,960 --> 00:00:25,799
Speaker 1: The system that ESPN uses to paint the line is

8
00:00:25,840 --> 00:00:29,000
Speaker 1: called first and ten and it's created by a company

9
00:00:29,040 --> 00:00:33,200
Speaker 1: called sport Vision. The simplest description of the system is this,

10
00:00:33,800 --> 00:00:36,559
Speaker 1: The first down line is drawn on the field with

11
00:00:36,640 --> 00:00:40,000
Speaker 1: the computer so that viewers seeing the game on TV

12
00:00:40,280 --> 00:00:42,839
Speaker 1: can see the line as though it were painted on

13
00:00:42,880 --> 00:00:45,320
Speaker 1: the field. Here are some of the problems that have

14
00:00:45,440 --> 00:00:49,000
Speaker 1: to be solved in order for this system to work. First,

15
00:00:49,280 --> 00:00:52,040
Speaker 1: the system has to know the orientation of the field

16
00:00:52,159 --> 00:00:54,960
Speaker 1: with respect to the camera so that it can paint

17
00:00:55,000 --> 00:00:57,680
Speaker 1: the first down line with the correct perspective from the

18
00:00:57,720 --> 00:01:01,400
Speaker 1: camera's point of view. Second, the system has to know,

19
00:01:01,720 --> 00:01:07,760
Speaker 1: in the same perspective framework exactly where every yard line is. Third,

20
00:01:07,800 --> 00:01:10,720
Speaker 1: given that the camera person can move the camera, the

21
00:01:10,840 --> 00:01:15,360
Speaker 1: system has to be able to sense the cameras movement tilt, pan, zoom,

22
00:01:15,360 --> 00:01:21,360
Speaker 1: and focus and understand the perspective change resulting from that movement. Fourth,

23
00:01:21,640 --> 00:01:25,440
Speaker 1: a football field is not flat. It crests very gently

24
00:01:25,480 --> 00:01:28,160
Speaker 1: in the middle to help rainwater run off, so the

25
00:01:28,240 --> 00:01:33,360
Speaker 1: line calculated by the system has to appropriately follow that curve. Five.

26
00:01:33,880 --> 00:01:37,400
Speaker 1: The football game is shot by multiple cameras at different

27
00:01:37,440 --> 00:01:40,200
Speaker 1: places in the stadium, so the system has to do

28
00:01:40,280 --> 00:01:44,520
Speaker 1: all this work for several different cameras. Six, the system

29
00:01:44,600 --> 00:01:47,640
Speaker 1: has to be able to sense when players, referees, or

30
00:01:47,680 --> 00:01:50,680
Speaker 1: the ball cross over the first down line so it

31
00:01:50,720 --> 00:01:53,840
Speaker 1: doesn't paint the line on top of them. And seventh,

32
00:01:54,200 --> 00:01:57,440
Speaker 1: the system has to be aware of superimposed graphics that

33
00:01:57,480 --> 00:02:00,960
Speaker 1: the network might overlay on the scene. There are probably

34
00:02:01,040 --> 00:02:05,040
Speaker 1: several other complications as well. It's a tough problem. To

35
00:02:05,160 --> 00:02:08,680
Speaker 1: solve these problems. The creators of the first intense system

36
00:02:08,720 --> 00:02:13,360
Speaker 1: combine hardware and software. First, each camera must have very

37
00:02:13,360 --> 00:02:18,320
Speaker 1: sensitive encoders attached so it can read the cameras angle, tilt, zoom,

38
00:02:18,320 --> 00:02:21,720
Speaker 1: and so on and send that information to the system.

39
00:02:21,760 --> 00:02:25,079
Speaker 1: The system must also have a detailed three D model

40
00:02:25,120 --> 00:02:27,960
Speaker 1: of the field so that it knows where each yard

41
00:02:28,000 --> 00:02:32,120
Speaker 1: line is by integrating the tilt, pan, and zoom information

42
00:02:32,160 --> 00:02:35,200
Speaker 1: with the three D model, the system can calculate where

43
00:02:35,200 --> 00:02:38,799
Speaker 1: the line should go. Then the system uses color palettes

44
00:02:38,880 --> 00:02:42,080
Speaker 1: for the field and for the players, referees, and balls

45
00:02:42,120 --> 00:02:46,280
Speaker 1: to recognize pixel by pixel, whether it's looking at the

46
00:02:46,320 --> 00:02:50,280
Speaker 1: field or something else. This way, only the field gets painted.

47
00:02:50,600 --> 00:02:53,800
Speaker 1: According to the sport Vision website, all of this computation

48
00:02:53,919 --> 00:02:57,680
Speaker 1: requires a lot of equipment. There are eight computers, three

49
00:02:57,720 --> 00:03:01,440
Speaker 1: sets of special encoders, and a lot of wiring dedicated

50
00:03:01,480 --> 00:03:05,320
Speaker 1: to generating the virtual first down line in video format.

51
00:03:05,720 --> 00:03:08,320
Speaker 1: Who would have thought that it would be this complicated.

52
00:03:09,360 --> 00:03:12,239
Speaker 1: Do you have any ideas or suggestions for this podcast?

53
00:03:12,639 --> 00:03:15,320
Speaker 1: If so, please send me an email at podcast at

54
00:03:15,320 --> 00:03:18,040
Speaker 1: how stuff works dot com. For more on this and

55
00:03:18,080 --> 00:03:23,200
Speaker 1: thousands of other topics, go to how stuff works dot com.