What is Timecode?

Ben Grosser

Former Manager, VMIL

I (Ben) grabbed the following post sequence off of rec.video.professional. The articles are all different explanations to the question 'What is Timecode?'. I generally like to have several sources of information for a question I'm interested in, so I've included all of them. Enjoy.

What is Timecode?

Time code is a data stream that is laid onto video tape in either an analog form via a special audio channel, or as digital information on lines 16 and 18 of the the vertical interval.

What does it do? Time code assigns a specific time to each frame of video so that when you are editing a progrom using a computer controlled editor any specific frame can be accessed and any resulting edit decisions are frame accurate over and over again. A time code number looks like clock time, ie.. 01:02:58:23. Wait you say, what is that :23 at the end, my wall clock doesn't count like that. That is the frame count. Every second of picture is made up of 30 frames of video(actually 29.97 frames), so when the time code is running you see a very fast frame count in the final two digits.

There are two types of time code: Drop Frame and Non Drop Frame. It the old days when TV was only black and white there really were exactly 30 frames of video every second. When color TV was invented addtional space was required in the scan of each picture to accomodate the color information and timing signals. To do this a slight modification was made to the the NTSC standard that reduced the frame count to 29.97. Your home TV see's no problem with this and can still synchronize to to the signal. BUT, changing the frame count required a modification to timecode so that when you added up the the culmulative time of the show, it would equal real time(clock time). This is Drop Frame time code. What it does it skip the count of a frame of video at the top of each minute, except for every 10th minute. Example: a tape is running along reading drop frame time code, if you slowed the tape down so that you could see each number counting it would go like this as the count got to the next minute 01:02:59:27...01:02:59:28...01:03:00:00. See a frame count was dropped. The frame is still there, it just was given a number one frame ahead. A dropped frame. By doing this on every minute, except every 10th minute, your timecode and picture running time stays in sync with real time.

Do you need timecode? All professional videotape production and post production requires timecode to edit programs and to facilitate the automatic playback systems that most TV stations and networks use today. Home systems do not record time code as it is only a frame numbering system, not an integral part of the video signal. What all VTR's do record and you cannot edit without is control track. That is why you preblack a tape, to laydown control track not timecode. Control track is a timing pulse that is laid onto the tape to provide a signal to the scanner in order to lock the scanner of any VTR to the scanner of the original VTR that blacked the tape. Timecode normally gets laid at the same time because it is a standard function of broadcast quality machines.

Whats a scanner? The round drum you see inside a VTR that the tape goes around. It contains the record, playback,erase and sync heads.

Can you put timecode on a pre existing tape? Yes and no. Some VTR's have the ability to reinsert time code onto an existing tape. 1",Betacam, D2,D3 to name a few can do this. This is done to the analog timecode signal only. The digital time code signal is recorded as part of the picture and can not be reinserted without erasing the picture.

Hope all this helps. Contact me with any further questions

Elliot Roth
Senior Editor
Creative Post
eroth@mindspring.com

> What I know is this - you have to 'pre-black' a tape before you can > do any editting with it.

Pre-blacking is good practice but not essential if you are doing assemble- edits, i.e. sound and vision simultaneously.

> Apparently pre-blacking is really just putting > time code on the tape, which allows editting equipment to take control > of the tape.

It puts CONTROL TRACK on the tape, not time-code. It is essential to have control-track on the tape if you wish to do INSERT edits i.e vision only or sound only, inserted over previous material.

>In the past, I have >done 'insert' editting on pre- blacked > tapes using a Sony BVU-950 U-Matic >SP VTR. I have also transferred > digital image sequences one at a time from >a workstation to a pre-blacked > tape. This also involved using a scan >converter and animation controller. > But I am still very fuzzy about what time code really is. I know > that it's information somewhere on the tape.

Time code is a generated signal that can be put on the tape in two ways. It gives each frame a dedicated number so any single frame can be identified and searched for. The eight bits used give you two each of hours, minutes, seconds and frames. There is also a facility for adding user-bits, identification information you can add yourself. BTW the hours bits are often used to identify reel numbers instead of hours.

VITC time-code is added to the picture information, hidden within the top non- visual lines of each frame. It can only be recorded during shooting as it is a part of the picture information. Re-record picture on the master tape and you lose the continuity of the time code. Of course, this does not apply when editing on to another tape.

Longtitudinal time code is recorded on one of the sound tracks. You lose one track.

> I also know that a > seqence can be recorded onto videotape without time code being there. > So let's say I pre-black a tape, then record a seqence onto that tape > from a video camera. I do this without using any of the special editting > functions on the VTR. I simply push the 'record' button. Will this > process erase the time code? If not, will the images (frames, fields, > etc) be correctly correlated to the time code.

You don't need to black a camera tape. If you are recording into a separate VCR, your camera has a time code generator with output socket and your machine has time code in, you could record time code on your VCR. Remember, no time code exists on your pre-blacked tape, only control code. This is interrupted whenever you press record but not in insert-edit mode. You can both pre and post-record longtitudinal time code on to your tapes.

> Guess what I'm asking boils down to this. Is it possible to have > time code on a tape that does not correctly correspond to the visual > information on the tape?

You are the one doing the settings.. Put the numbers to the pictures as you see fit, or vice versa.

> Also, is it possible to add time code to > a tape that already has visual information on it without corrupting > the visual stuff?

Yes. See above.

Finally, time code, in all its manifestations is truly a black art. I have been using it for years and I still get as confused as hell when I have to do something new I haven't done before or regularly.

Bon chance!

Maurice R Fleisher

Time code is best thought of as an address. Like a street address, each house has a different number. This makes it possible for the postal service to deliver the mail to the proper recipient.The time code address allows you, the editor, to find the exact frame in which to insert or delete a picture or audio information. Blacking a tape, allows you to do Insert Editing (video and/or audio only) by laying down a CONTROL TRACK or SYNC. Laying black, does not neccesarily mean that you are laying Time Code. "Blacking a tape" lays down COMPOSITE VIDEO, which consists of video information (black), and sync (electronic pulses). These pulses can be assigned a code (Time Code) to differentiate each. The Time Code can be assigned after blacking by using specialized equipment, however it is recomended that you do this during blacking. If you INSERT EDIT video from a camera onto a blacked tape w/timecode, the timecode will remain intact. If you push play and record, you will interupt the timecode. INSERT Editing allows you to insert 'video only' or 'audio only' or 'video and audio only' without affecting the control track or timecode.

If you need more (there IS more), you can e-mail me. Marc Gaynor,

IMAGEvideo@aol.com

Subject: Re: Exactly What Is Time Code (fwd)

Though no video engineer, I have worked with time code for many years (as an editor and cameraman) and have a practical understanding of its use. I will try to answer your questions...

Moderator rec.video.professional wrote: > > I have a few questions about SMPTE time code. My fields are aerospace > engineering and computer graphics, so I am far from an expert on technical > video topics. I have some experience producing graphics sequences using > commercial animation software or my own engineering simulations on SGI. > > What I know is this - you have to 'pre-black' a tape before you can > do any editting with it. Apparently pre-blacking is really just putting > time code on the tape, which allows editting equipment to take control > of the tape.

Actually blacking a tape and putting down time are two different functions, usually done together, but not always. Blacking a tape is recording a continuous black video signal down on a tape. Usually time code is recorded when blacking - but not always.

For example, if you were to record black on a VHS tape, you probably would not record time (unless you put it on an audio track) because VHS had no track dedicated to recording time code. Similarly, I have seen some Betacam tapes recorded without time code. Perhaps some of Sony's wonderful UVW decks come without time code cards, or someone removed them. I don't know how they did, but I know they did because we had to edit the tapes.

More typically, when using professional formats (e.g. Betacam, BVU 3/4" decks, etc.) time code is recorded when black or any other picture is recorded to the tape.

In the past, I have done 'insert' editting on pre-blacked > tapes using a Sony BVU-950 U-Matic SP VTR. I have also transferred > digital image sequences one at a time from a workstation to a pre-blacked > tape. This also involved using a scan converter and animation controller.

Edit functions could be done with or without time code. Time code makes these functions frame accurate. Without it, you must depend on control track which is like the VTR counting the pulses of the frames passing.

The problem with control track editing is that the VTRs don't count it perfectly. Typically, they are accurate within +/- 2 frames FOR EACH PASS. If you make several previews or passes at your edit, this error may compound.

Time code identifies each frame with a unique and sequential number. Usually, allows for frame accurate editing time after time.

As for single frame recording, time code is essential because if you edited with control track your typical error of 2 frames is greater than the amount of material you want to record at any one time, which is only one frame. Without time code, the results would be disasterous.

> > But I am still very fuzzy about what time code really is. I know > that it's information somewhere on the tape. I also know that a > seqence can be recorded onto videotape without time code being there. > So let's say I pre-black a tape, then record a seqence onto that tape > from a video camera.

There is no point that I can think of to pre-black a tape and then record over it with a camera. (Unless your point is hypothetical.)

> I do this without using any of the special editing > functions on the VTR. I simply push the 'record' button. Will this > process erase the time code?

Yes. If you push the Record button you will (on every deck I have used) record new time code and everything else - video, audio, control track, etc.

> If not, will the images (frames, fields, > etc) be correctly correlated to the time code.

Generally, to get images to correlate to particular time code, you would black a tape and lay down time code. (TC can be pre-set to start at any number from 0 hours up to but not including 24 hours.) Then you would INSERT edit your video and audio as you wish at particular time code numbers. This way the time code is preserved and you can line up your shots as you please.

It is worth pointing out that, generally, the time code is a tool that editors would rather pay less attention to, except when it's needed. Editors think usually about lining up a shot at a particular point in the show more than at a particular time code. But there are exceptions to this.

Indeed, the advent of non-linear editing has allowed editor to think about time code much less. But it is still an underlying issue, function and tool that needs to be understood and used correctly, particularly when digitizing material from tape, or laying program back to tape.

> > Guess what I'm asking boils down to this. Is it possible to have > time code on a tape that does not correctly correspond to the visual > information on the tape?

It depends upon what you mean as "correctly"?

> Also, is it possible to add time code to > a tape that already has visual information on it without corrupting > the visual stuff?

Generally, new picture and audio is recorded when time code is recorded. There may be some special functions on certain decks which allow you to insert time without recording over video and audio.

I have noticed a time code insert button on some BVW Betacam SP decks. Interesting, I once needed this myself and called around to several professional dub houses to find out if it could be done. There was a surprising amount of ignorance on the subject, and I am not sure if I ever received the correct answer.

You could always add time code to an audio track. We used to do that in the old days to 3/4" tape. We called it post-coding. The problem is that most modern editors read time code through the serial port/cable, not through a seperate cable like they used to. So how would you feed this audio track time code into your editor? You could of course feed it to a time code reader, if all you want to do is DISPLAY the time code, not edit with it.

I hope this helps.

Jon Lieberman
American Film & Video

Short answer to "what is timecode?": It refers to a number that correspondes to an exact frame on the video tape. Ya ever shoot pictures (film, 35mm or whatever) and take a look at the negative? Well if you did, you would see numbers along the edge of the film, x and xA. Well just imagine that you didn't have the "xA" and the corresponding number was always "within" the boundries of the individual picture frame. Well, you've got yourself a "code". Now, just imagine that everytime you took pictures, this same, exact setup would manifest itself. This is the basis for timcode. Each individual frame of video (30 per second) gets a a corresponding number assigned to it. Unless you change the timecode (by re-writing or over-writing it), that number in time will forever stay with that particular frame. It's like a time stamp, an index.

Will your timecode change if you do a hard record on a pre-blacked tape? Yup. Will it change if you do an assemble edit onto the tape? Yup. An insert edit? Nope.

> > Guess what I'm asking boils down to this. Is it possible to have > time code on a tape that does not correctly correspond to the visual > information on the tape?

I really don't understand this question. Timecode runs on the 24 hour clock cycle, meaning from 00:00:00.00 to 23:59:59.29 (remember 30 frames per second for NTSC). So you can pre-black a tape to start with any timecode you wish, 14:22:44.15 or 00:12:00.09, and it wil run continuously for the length of the videotape (always pre-black your tapes from beginning to end ;) ). If you insert edit video onto the tape from a certain point, your video and timecode will correlate from that point. If you change the point of the edit, then your correlation will change also.

A little clarity, or an example, would most likely bring a better answer to this question.

> Also, is it possible to add time code to > a tape that already has visual information on it without corrupting > the visual stuff?

Yes, very easily on most professional level machines (and some pro-sumer). It's called a re-stripe.

Patrick J. Harris, II
The Harris Group
hgroup@earthlink.net

Imaging Technology Group
Beckman Institute for Advanced Science and Technology
University of Illinois at Urbana-Champaign
405 N. Mathews, Urbana, IL 61801

Date Issued: 23 May 1997

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Time code is a data stream that is laid onto video tape in either an analog form via a special audio channel, or as digital information on lines 16 and 18 of the the vertical interval. What does it do? Time code assigns a specific time to each frame of video so that when you are editing a progrom using a computer controlled editor any specific frame can be accessed and any resulting edit decisions are frame accurate over and over again. A time code number looks like clock time, ie.. 01:02:58:23. Wait you say, what is that :23 at the end, my wall clock doesn't count like that. That is the frame count. Every second of picture is made up of 30 frames of video(actually 29.97 frames), so when the time code is running you see a very fast frame count in the final two digits. There are two types of time code: Drop Frame and Non Drop Frame. It the old days when TV was only black and white there really were exactly 30 frames of video every second. When color TV was invented addtional space was required in the scan of each picture to accomodate the color information and timing signals. To do this a slight modification was made to the the NTSC standard that reduced the frame count to 29.97. Your home TV see's no problem with this and can still synchronize to to the signal. BUT, changing the frame count required a modification to timecode so that when you added up the the culmulative time of the show, it would equal real time(clock time). This is Drop Frame time code. What it does it skip the count of a frame of video at the top of each minute, except for every 10th minute. Example: a tape is running along reading drop frame time code, if you slowed the tape down so that you could see each number counting it would go like this as the count got to the next minute 01:02:59:27...01:02:59:28...01:03:00:00. See a frame count was dropped. The frame is still there, it just was given a number one frame ahead. A dropped frame. By doing this on every minute, except every 10th minute, your timecode and picture running time stays in sync with real time. Do you need timecode? All professional videotape production and post production requires timecode to edit programs and to facilitate the automatic playback systems that most TV stations and networks use today. Home systems do not record time code as it is only a frame numbering system, not an integral part of the video signal. What all VTR's do record and you cannot edit without is control track. That is why you preblack a tape, to laydown control track not timecode. Control track is a timing pulse that is laid onto the tape to provide a signal to the scanner in order to lock the scanner of any VTR to the scanner of the original VTR that blacked the tape. Timecode normally gets laid at the same time because it is a standard function of broadcast quality machines. Whats a scanner? The round drum you see inside a VTR that the tape goes around. It contains the record, playback,erase and sync heads. Can you put timecode on a pre existing tape? Yes and no. Some VTR's have the ability to reinsert time code onto an existing tape. 1",Betacam, D2,D3 to name a few can do this. This is done to the analog timecode signal only. The digital time code signal is recorded as part of the picture and can not be reinserted without erasing the picture. Hope all this helps. Contact me with any further questions Elliot Roth Senior Editor Creative Post eroth@mindspring.com > What I know is this - you have to 'pre-black' a tape before you can > do any editting with it. Pre-blacking is good practice but not essential if you are doing assemble- edits, i.e. sound and vision simultaneously. > Apparently pre-blacking is really just putting > time code on the tape, which allows editting equipment to take control > of the tape. It puts CONTROL TRACK on the tape, not time-code. It is essential to have control-track on the tape if you wish to do INSERT edits i.e vision only or sound only, inserted over previous material. >In the past, I have >done 'insert' editting on pre- blacked > tapes using a Sony BVU-950 U-Matic >SP VTR. I have also transferred > digital image sequences one at a time from >a workstation to a pre-blacked > tape. This also involved using a scan >converter and animation controller. > But I am still very fuzzy about what time code really is. I know > that it's information somewhere on the tape. Time code is a generated signal that can be put on the tape in two ways. It gives each frame a dedicated number so any single frame can be identified and searched for. The eight bits used give you two each of hours, minutes, seconds and frames. There is also a facility for adding user-bits, identification information you can add yourself. BTW the hours bits are often used to identify reel numbers instead of hours. VITC time-code is added to the picture information, hidden within the top non- visual lines of each frame. It can only be recorded during shooting as it is a part of the picture information. Re-record picture on the master tape and you lose the continuity of the time code. Of course, this does not apply when editing on to another tape. Longtitudinal time code is recorded on one of the sound tracks. You lose one track. > I also know that a > seqence can be recorded onto videotape without time code being there. > So let's say I pre-black a tape, then record a seqence onto that tape > from a video camera. I do this without using any of the special editting > functions on the VTR. I simply push the 'record' button. Will this > process erase the time code? If not, will the images (frames, fields, > etc) be correctly correlated to the time code. You don't need to black a camera tape. If you are recording into a separate VCR, your camera has a time code generator with output socket and your machine has time code in, you could record time code on your VCR. Remember, no time code exists on your pre-blacked tape, only control code. This is interrupted whenever you press record but not in insert-edit mode. You can both pre and post-record longtitudinal time code on to your tapes. > Guess what I'm asking boils down to this. Is it possible to have > time code on a tape that does not correctly correspond to the visual > information on the tape? You are the one doing the settings.. Put the numbers to the pictures as you see fit, or vice versa. > Also, is it possible to add time code to > a tape that already has visual information on it without corrupting > the visual stuff? Yes. See above. Finally, time code, in all its manifestations is truly a black art. I have been using it for years and I still get as confused as hell when I have to do something new I haven't done before or regularly. Bon chance! Maurice R Fleisher Time code is best thought of as an address. Like a street address, each house has a different number. This makes it possible for the postal service to deliver the mail to the proper recipient.The time code address allows you, the editor, to find the exact frame in which to insert or delete a picture or audio information. Blacking a tape, allows you to do Insert Editing (video and/or audio only) by laying down a CONTROL TRACK or SYNC. Laying black, does not neccesarily mean that you are laying Time Code. "Blacking a tape" lays down COMPOSITE VIDEO, which consists of video information (black), and sync (electronic pulses). These pulses can be assigned a code (Time Code) to differentiate each. The Time Code can be assigned after blacking by using specialized equipment, however it is recomended that you do this during blacking. If you INSERT EDIT video from a camera onto a blacked tape w/timecode, the timecode will remain intact. If you push play and record, you will interupt the timecode. INSERT Editing allows you to insert 'video only' or 'audio only' or 'video and audio only' without affecting the control track or timecode. If you need more (there IS more), you can e-mail me. Marc Gaynor, IMAGEvideo@aol.com Subject: Re: Exactly What Is Time Code (fwd) Though no video engineer, I have worked with time code for many years (as an editor and cameraman) and have a practical understanding of its use. I will try to answer your questions... Moderator rec.video.professional wrote: > > I have a few questions about SMPTE time code. My fields are aerospace > engineering and computer graphics, so I am far from an expert on technical > video topics. I have some experience producing graphics sequences using > commercial animation software or my own engineering simulations on SGI. > > What I know is this - you have to 'pre-black' a tape before you can > do any editting with it. Apparently pre-blacking is really just putting > time code on the tape, which allows editting equipment to take control > of the tape. Actually blacking a tape and putting down time are two different functions, usually done together, but not always. Blacking a tape is recording a continuous black video signal down on a tape. Usually time code is recorded when blacking - but not always. For example, if you were to record black on a VHS tape, you probably would not record time (unless you put it on an audio track) because VHS had no track dedicated to recording time code. Similarly, I have seen some Betacam tapes recorded without time code. Perhaps some of Sony's wonderful UVW decks come without time code cards, or someone removed them. I don't know how they did, but I know they did because we had to edit the tapes. More typically, when using professional formats (e.g. Betacam, BVU 3/4" decks, etc.) time code is recorded when black or any other picture is recorded to the tape. In the past, I have done 'insert' editting on pre-blacked > tapes using a Sony BVU-950 U-Matic SP VTR. I have also transferred > digital image sequences one at a time from a workstation to a pre-blacked > tape. This also involved using a scan converter and animation controller. Edit functions could be done with or without time code. Time code makes these functions frame accurate. Without it, you must depend on control track which is like the VTR counting the pulses of the frames passing. The problem with control track editing is that the VTRs don't count it perfectly. Typically, they are accurate within +/- 2 frames FOR EACH PASS. If you make several previews or passes at your edit, this error may compound. Time code identifies each frame with a unique and sequential number. Usually, allows for frame accurate editing time after time. As for single frame recording, time code is essential because if you edited with control track your typical error of 2 frames is greater than the amount of material you want to record at any one time, which is only one frame. Without time code, the results would be disasterous. > > But I am still very fuzzy about what time code really is. I know > that it's information somewhere on the tape. I also know that a > seqence can be recorded onto videotape without time code being there. > So let's say I pre-black a tape, then record a seqence onto that tape > from a video camera. There is no point that I can think of to pre-black a tape and then record over it with a camera. (Unless your point is hypothetical.) > I do this without using any of the special editing > functions on the VTR. I simply push the 'record' button. Will this > process erase the time code? Yes. If you push the Record button you will (on every deck I have used) record new time code and everything else - video, audio, control track, etc. > If not, will the images (frames, fields, > etc) be correctly correlated to the time code. Generally, to get images to correlate to particular time code, you would black a tape and lay down time code. (TC can be pre-set to start at any number from 0 hours up to but not including 24 hours.) Then you would INSERT edit your video and audio as you wish at particular time code numbers. This way the time code is preserved and you can line up your shots as you please. It is worth pointing out that, generally, the time code is a tool that editors would rather pay less attention to, except when it's needed. Editors think usually about lining up a shot at a particular point in the show more than at a particular time code. But there are exceptions to this. Indeed, the advent of non-linear editing has allowed editor to think about time code much less. But it is still an underlying issue, function and tool that needs to be understood and used correctly, particularly when digitizing material from tape, or laying program back to tape. > > Guess what I'm asking boils down to this. Is it possible to have > time code on a tape that does not correctly correspond to the visual > information on the tape? It depends upon what you mean as "correctly"? > Also, is it possible to add time code to > a tape that already has visual information on it without corrupting > the visual stuff? Generally, new picture and audio is recorded when time code is recorded. There may be some special functions on certain decks which allow you to insert time without recording over video and audio. I have noticed a time code insert button on some BVW Betacam SP decks. Interesting, I once needed this myself and called around to several professional dub houses to find out if it could be done. There was a surprising amount of ignorance on the subject, and I am not sure if I ever received the correct answer. You could always add time code to an audio track. We used to do that in the old days to 3/4" tape. We called it post-coding. The problem is that most modern editors read time code through the serial port/cable, not through a seperate cable like they used to. So how would you feed this audio track time code into your editor? You could of course feed it to a time code reader, if all you want to do is DISPLAY the time code, not edit with it. I hope this helps. Jon Lieberman American Film & Video Short answer to "what is timecode?": It refers to a number that correspondes to an exact frame on the video tape. Ya ever shoot pictures (film, 35mm or whatever) and take a look at the negative? Well if you did, you would see numbers along the edge of the film, x and xA. Well just imagine that you didn't have the "xA" and the corresponding number was always "within" the boundries of the individual picture frame. Well, you've got yourself a "code". Now, just imagine that everytime you took pictures, this same, exact setup would manifest itself. This is the basis for timcode. Each individual frame of video (30 per second) gets a a corresponding number assigned to it. Unless you change the timecode (by re-writing or over-writing it), that number in time will forever stay with that particular frame. It's like a time stamp, an index. Will your timecode change if you do a hard record on a pre-blacked tape? Yup. Will it change if you do an assemble edit onto the tape? Yup. An insert edit? Nope. > > Guess what I'm asking boils down to this. Is it possible to have > time code on a tape that does not correctly correspond to the visual > information on the tape? I really don't understand this question. Timecode runs on the 24 hour clock cycle, meaning from 00:00:00.00 to 23:59:59.29 (remember 30 frames per second for NTSC). So you can pre-black a tape to start with any timecode you wish, 14:22:44.15 or 00:12:00.09, and it wil run continuously for the length of the videotape (always pre-black your tapes from beginning to end ;) ). If you insert edit video onto the tape from a certain point, your video and timecode will correlate from that point. If you change the point of the edit, then your correlation will change also. A little clarity, or an example, would most likely bring a better answer to this question. > Also, is it possible to add time code to > a tape that already has visual information on it without corrupting > the visual stuff? Yes, very easily on most professional level machines (and some pro-sumer). It's called a re-stripe. Patrick J. Harris, II The Harris Group hgroup@earthlink.net Imaging Technology Group Beckman Institute for Advanced Science and Technology University of Illinois at Urbana-Champaign 405 N. Mathews, Urbana, IL 61801 Date Issued: 23 May 1997 Copyright © 1997, Board of Trustees of the University of Illinois, All Rights Reserved.
The ITG is part of the Beckman Institute for Advanced Science and Technology at the University of Illinois.
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