How do you erase items digitally? at DVinfo.net

Dan Measel · July 1st, 2004, 10:53 PM

I was watching the 10 minute flick school on Robert Rodriguez's Once Upon a Time in Mexico and he was showing how he used cables to hold the actors and then erased the cables in post for the scene. He even erased some people that were in a scene that were crew and not actors.

I was amazed. How do you do that on a PC? Any ideas?

Ed Smith · July 2nd, 2004, 02:40 AM

Hi Dan,

You would use a compositing tool like Adobes After effects or Discreets Combustion, and simply erase the bits you do not use. However if you want more control and you have more money then I think Discreets Flame? is what I think most holywood films use.

Thanks,

Jaime Valles · July 2nd, 2004, 07:03 AM

Could one import the clip as still frames into Photoshop and then work on them one at a time? I've never tried this, but it seems that using Photoshop's clone stamp and healing tools one could digitally alter anything in the frame, even if the camera is not still, right? It would take a while, certainly, but if you do all the changes on a separate layer, and then modify that layer frame by frame, you wouldn't have to start from scratch every time.

Of course, I haven't actually tried this yet, so I could be totally wrong, but in theory it would seem to work.

K. Forman · July 2nd, 2004, 07:09 AM

You could certainly use Photoshop, and import a clip in .flm format. The downside, besides being extremely time consuming, is the fact that it would be almost impossible to maintain consistancy between frames.

Dan Measel · July 2nd, 2004, 09:26 AM

So you can erase an entire person from a scene with adobe after effects? Then I guess you just paint in over the area where the person was erased from? After effects does that as well? The photoshop frame by frame method sounds very difficult. Is using Adobe after effects or the discreet products fairly easy? Ed have you (or anyone else) done this (erasing) before? I'm not familiar with those programs but would certainly be interested in getting one if they're that good and wouldn't take 6 months to learn how to use.

Keith Loh · July 2nd, 2004, 12:41 PM

I'm actually faced with this problem but.. erasing an entire person would be quite a chore. My task is wire erasure. Unfortunately, unless that person is totally still and the scene is static, you will have to be doing lots of painting whether it is with Photoshop or with AfterEffects. With AfterEffects.. again I haven't looked at this myself .. I think there is a tracking method whereby you do one matte and then use the same object to overlay the background over the person or object you want taken out. But I think inevitably you will have to do some frame by frame painting.

Frank Ladner · July 2nd, 2004, 01:00 PM

Scenes with no camera movement are really easy, since you can record a backplate with no actors and then record the same thing with actors (assuming the camera stays in the exact same place with the exact same settings and the environment - light, weather, clouds, etc...are all relatively the same)...and then in After effects, set the backplate underneath and mask out the unwanted elements from the top layer, revealing the backplate underneath.

Nowadays people have gotten used to these handheld camera shots with all the elements composited seamlessly, so static shots just don't have that realism and impact.

The professionals use software that tracks feature points in a scene and 'learns' what's where. The user selects what to remove and the software overwrites it with parts of the background that it knows should be in the place of the object.
Basically, as stuff moves around, it 'builds' the background, picking bits and pieces from here and there as they become unobstructed by moving objects..

If you want to be impressed with automated object removal, check this out:

http://www.2d3.com/jsp/products/prod...duct=pixeldust

This product is mind boggling.

K. Forman · July 2nd, 2004, 01:09 PM

The price will boggle your mind as well. And I really hope it works, because support is $2000 a year, or $200 a month. There is also support @ $99 per call?

We are on the wrong end of video...

Frank Ladner · July 2nd, 2004, 01:16 PM

LOL!

Keith, that is true! I know a lot of us are stuck doing it by hand.

Yeah, the PixelDust guys also make Boujou ($10,000 motion tracker). But SynthEyes ($349) can do the same thing, from the reviews I have read, which makes me hope that someone like that would write an automated object-removal program that we could maybe afford.

http://www.ssontech.com/

...actually, SynthEyes supposedly has a rotoscope feature in it. I've played with the demo, but didn't try that part of it.

Anybody use this before?

Rob Lohman · July 3rd, 2004, 06:39 AM

Automated object removal will never happen if you want it to look
good. Why? Because a computer does not know about objects.
But I hear everyone say: what about quantum computing and
nano stuff. Let's first get there, mkay? <g>

It *IS* very time consuming and takes a lot of practice to get it
looking right etc. You can do it if you are good enough and have
enough time on your hands.

Nick Jushchyshyn · July 5th, 2004, 05:43 PM

PixelFarm has PFTrack which also does this and the student price of the program is only $80. (Full price is a few thousand though).

Also, there are LOTS of ways to pull this off.
RealViz makes programs for Photogrametry that allow you to make a 3d model based on hi res photos. You can then "move" a 3d camera within the environement with data from Motion Tracker which now gives you a moving, clean background to fill in where you erase objects, even when the camera is moving.

For quick shots, I still just use the Video Paint rotoscoping tool that comes with the Media Studio Pro DV editiing suite. Having previously used the Premiere->photoshop->Premiere method, I can say that the Ulead solution is MUCH easier and faster.

I'm currently learning the RealViz tools through my visual effects training. In most common situations, especially for wires, it's not too difficult at all, even at high resolutions.

Have fun.

Glenn Chan · July 5th, 2004, 10:35 PM

There are a few programs out there that will do motion tracking, which allows you to erase things in certain situations. With motion tracking, you drag select a box around a static area that the program locks onto. It will keep the whole image still, or let you move masks according to camera movement. This is effective at getting rid of logos and such with footage shot handheld.

Frank Ladner · July 6th, 2004, 06:54 AM

For the guys that are rotoscoping in Photoshop, try this:

After you have selected your object, use Save Selection. Then when you load your next frame, use Load Selection and modify/move the selection to fit the object in the new frame. This keeps your mask more consistent from frame to frame, cutting back on the 'jitter'.

July 1st, 2004, 10:53 PM	#1
Dan Measel Regular Crew Join Date: Dec 2002 Location: Athens, GA Posts: 196	How do you erase items digitally? I was watching the 10 minute flick school on Robert Rodriguez's Once Upon a Time in Mexico and he was showing how he used cables to hold the actors and then erased the cables in post for the scene. He even erased some people that were in a scene that were crew and not actors. I was amazed. How do you do that on a PC? Any ideas?

July 2nd, 2004, 02:40 AM	#2
Ed Smith Wrangler Join Date: Jan 2002 Location: Hampshire, England Posts: 1,545	Hi Dan, You would use a compositing tool like Adobes After effects or Discreets Combustion, and simply erase the bits you do not use. However if you want more control and you have more money then I think Discreets Flame? is what I think most holywood films use. Thanks, __________________ Ed Smith Hampshire, UK Good things come to those who wait My Skiing web www.Frostytour.co.uk For quick answers Search dvinfo.net \| The best in the business: dvinfo.net Sponsors

July 2nd, 2004, 07:09 AM	#4
K. Forman Capt. Quirk Join Date: Apr 2002 Location: Middle of the woods in Georgia Posts: 3,596	You could certainly use Photoshop, and import a clip in .flm format. The downside, besides being extremely time consuming, is the fact that it would be almost impossible to maintain consistancy between frames. __________________ www.SmokeWagonLeather.us

July 2nd, 2004, 12:41 PM	#6
Keith Loh Air China Pilot Join Date: May 2002 Location: Vancouver, B.C. Posts: 2,389	I'm actually faced with this problem but.. erasing an entire person would be quite a chore. My task is wire erasure. Unfortunately, unless that person is totally still and the scene is static, you will have to be doing lots of painting whether it is with Photoshop or with AfterEffects. With AfterEffects.. again I haven't looked at this myself .. I think there is a tracking method whereby you do one matte and then use the same object to overlay the background over the person or object you want taken out. But I think inevitably you will have to do some frame by frame painting. __________________ -- Visit http://www.KeithLoh.com \| stuff about living in Vancouver \| My Flickr photo gallery

July 2nd, 2004, 01:09 PM	#8
K. Forman Capt. Quirk Join Date: Apr 2002 Location: Middle of the woods in Georgia Posts: 3,596	The price will boggle your mind as well. And I really hope it works, because support is $2000 a year, or $200 a month. There is also support @ $99 per call? We are on the wrong end of video... __________________ www.SmokeWagonLeather.us

July 2nd, 2004, 07:03 AM	#3
Jaime Valles Major Player Join Date: Aug 2002 Location: New York City, NY Posts: 316	Could one import the clip as still frames into Photoshop and then work on them one at a time? I've never tried this, but it seems that using Photoshop's clone stamp and healing tools one could digitally alter anything in the frame, even if the camera is not still, right? It would take a while, certainly, but if you do all the changes on a separate layer, and then modify that layer frame by frame, you wouldn't have to start from scratch every time. Of course, I haven't actually tried this yet, so I could be totally wrong, but in theory it would seem to work.

July 2nd, 2004, 09:26 AM	#5
Dan Measel Regular Crew Join Date: Dec 2002 Location: Athens, GA Posts: 196	So you can erase an entire person from a scene with adobe after effects? Then I guess you just paint in over the area where the person was erased from? After effects does that as well? The photoshop frame by frame method sounds very difficult. Is using Adobe after effects or the discreet products fairly easy? Ed have you (or anyone else) done this (erasing) before? I'm not familiar with those programs but would certainly be interested in getting one if they're that good and wouldn't take 6 months to learn how to use.

July 2nd, 2004, 01:00 PM	#7
Frank Ladner Major Player Join Date: Aug 2003 Location: Poplarville, MS Posts: 453	Scenes with no camera movement are really easy, since you can record a backplate with no actors and then record the same thing with actors (assuming the camera stays in the exact same place with the exact same settings and the environment - light, weather, clouds, etc...are all relatively the same)...and then in After effects, set the backplate underneath and mask out the unwanted elements from the top layer, revealing the backplate underneath. Nowadays people have gotten used to these handheld camera shots with all the elements composited seamlessly, so static shots just don't have that realism and impact. The professionals use software that tracks feature points in a scene and 'learns' what's where. The user selects what to remove and the software overwrites it with parts of the background that it knows should be in the place of the object. Basically, as stuff moves around, it 'builds' the background, picking bits and pieces from here and there as they become unobstructed by moving objects.. If you want to be impressed with automated object removal, check this out: http://www.2d3.com/jsp/products/prod...duct=pixeldust This product is mind boggling.

July 2nd, 2004, 01:16 PM	#9
Frank Ladner Major Player Join Date: Aug 2003 Location: Poplarville, MS Posts: 453	LOL! Keith, that is true! I know a lot of us are stuck doing it by hand. Yeah, the PixelDust guys also make Boujou ($10,000 motion tracker). But SynthEyes ($349) can do the same thing, from the reviews I have read, which makes me hope that someone like that would write an automated object-removal program that we could maybe afford. http://www.ssontech.com/ ...actually, SynthEyes supposedly has a rotoscope feature in it. I've played with the demo, but didn't try that part of it. Anybody use this before?

July 3rd, 2004, 06:39 AM	#10
Rob Lohman RED Code Chef Join Date: Oct 2001 Location: Holland Posts: 12,514	Automated object removal will never happen if you want it to look good. Why? Because a computer does not know about objects. But I hear everyone say: what about quantum computing and nano stuff. Let's first get there, mkay? <g> It IS very time consuming and takes a lot of practice to get it looking right etc. You can do it if you are good enough and have enough time on your hands. __________________ Rob Lohman, visuar@iname.com DV Info Wrangler & RED Code Chef Join the DV Challenge \| Lady X Search DVinfo.net for quick answers \| Buy from the best: DVinfo.net sponsors

July 5th, 2004, 05:43 PM	#11
Nick Jushchyshyn Major Player Join Date: Feb 2004 Location: Philadelphia, PA, USA Posts: 548	PixelFarm has PFTrack which also does this and the student price of the program is only $80. (Full price is a few thousand though). Also, there are LOTS of ways to pull this off. RealViz makes programs for Photogrametry that allow you to make a 3d model based on hi res photos. You can then "move" a 3d camera within the environement with data from Motion Tracker which now gives you a moving, clean background to fill in where you erase objects, even when the camera is moving. For quick shots, I still just use the Video Paint rotoscoping tool that comes with the Media Studio Pro DV editiing suite. Having previously used the Premiere->photoshop->Premiere method, I can say that the Ulead solution is MUCH easier and faster. I'm currently learning the RealViz tools through my visual effects training. In most common situations, especially for wires, it's not too difficult at all, even at high resolutions. Have fun.

July 5th, 2004, 10:35 PM	#12
Glenn Chan Inner Circle Join Date: Jun 2003 Location: Toronto, Canada Posts: 4,750	There are a few programs out there that will do motion tracking, which allows you to erase things in certain situations. With motion tracking, you drag select a box around a static area that the program locks onto. It will keep the whole image still, or let you move masks according to camera movement. This is effective at getting rid of logos and such with footage shot handheld.

July 6th, 2004, 06:54 AM	#13
Frank Ladner Major Player Join Date: Aug 2003 Location: Poplarville, MS Posts: 453	For the guys that are rotoscoping in Photoshop, try this: After you have selected your object, use Save Selection. Then when you load your next frame, use Load Selection and modify/move the selection to fit the object in the new frame. This keeps your mask more consistent from frame to frame, cutting back on the 'jitter'.