Frame correction for LEANING

EuropeanMan · 18th October 2011, 16:14

DEi was a manufacturer of many Bollywood DVD9s in the 80s/90s timeframe. The problem with them is that MANY of their prints were messed up.

I wish I had a DVD9 to take a screenshot from. (Currently away from home) Basically the problem is this:

If I were to take a picture of someone. You'd see them standing up straight. With DEi, that same person would lean one way about 5 to 10 degrees. So this LEANING was consistent ALL the way through the movie. EROS was primarily another manufacturer who hired DEi to make prints of their catalogue. Some of those same films released THROUGH EROS had those same people standing up straight. HOW did DEi mess this up? Why do their prints LEAN while EROS doesn't? On top of it, DEi was known to heavily crop their films from all 4 sides. VERY rarely did they release a movie where it wasn't cropped and had the original A/R intact.

Is there ANY way to fix this, to get the frames BACK to lean the OPPOSITE way? I'd rather reAUTHOR my DEi titles because they are PROGRESSIVE, while EROS was always interlaced & badly on top of that...

Thanks in advance...

Ghitulescu · 18th October 2011, 16:57

Probably a picture from one of their movies would explain better what you mean by "lean"

jmac698 · 19th October 2011, 12:52

http://avisynth.org/mediawiki/SkewRows
Or even try reform
http://avisynth.org/vcmohan/Reform/Reform.html

Bloax · 19th October 2011, 13:57

Even though it's obvious now, I'll go ahead anyway.

Quote:

Originally Posted by Ghitulescu

Probably a picture from one of their movies would explain better what you mean by "lean"

I think he means something like this. Except way less extreme.

IanB · 19th October 2011, 21:58

@Bloax,

That is a classic example of row skewing. The right and left sides of the image being stitched 1 pixel further across as you scan from bottom to top is the key hint. SkewRows(1) is designed to fix exactly this. The true width should have been 1367 not 1366. Unfortunately the last 768 pixels from the end of the top row will be missing.
____________________

I suspect EuropeanMan's problem is going to be skewing due to a fast shutter speed being used with a slow vertical blind style shutter, i.e. shutter is made from 2 blinds, 1st blind starts a down sweep exposing the film maybe taking 1/30th second to complete, the second blind follows close behind the first, maybe 1/250th second later, ending the exposure. So although the exposure time is 1/250th second the bottom of the negative is exposed 1/30th second after the top so things that move horizontally during this time become skewed in the final image. This shutter design was common for 35mm SLR type of still cameras, but I am not aware of this design being used in movie cameras. I guess when EuropeanMan posts a still we can stop guessing.

SkewRows can quickly adjust for only integer pixel skewing. Reform will more likely be required for the fractional shift needed. The hard bit is going to be the motion tracking, still image elements won't be skewed.

Ghitulescu · 20th October 2011, 17:09

Why don't we all wait for a sample instead of assuming things?

EuropeanMan · 21st October 2011, 04:44

Arghhhh I had totally forgotten about my thread...so so sorry...

here's an example from one particular DEi title: Khal Nayak (1993)

EuropeanMan · 21st October 2011, 05:03

^ this is a PRIME example...

EuropeanMan · 21st October 2011, 05:08

I also realise that IF there was a way to fix this, I'd have to crop on both sides just to get the main part of the frame "perpendicular" so to speak. Each side's corner/triangle would then be gone...

manono · 22nd October 2011, 08:40

If you just want to rotate it a little bit clockwise, then Fizick's Rotate filter is what you want:

http://avisynth.org/warpenterprises/

Rotate(1.5) rotates it one and a half degrees clockwise. And as you said, you'll have to crop and resize.

jmac698 · 22nd October 2011, 13:09

It's not a rotation, you need reform.

EuropeanMan · 24th October 2011, 05:17

^ could you please elaborate on REFORM? thanks

manono · 24th October 2011, 08:25

Quote:

Originally Posted by EuropeanMan

^ could you please elaborate on REFORM? thanks

He already linked to it earlier:

http://avisynth.org/vcmohan/Reform/Reform.html

poisondeathray · 24th October 2011, 21:27

Another option is vdub's perspective filter , or use batch image processing as stills like photoshop gimp's shear filter . You can fix it quite easily in after effects as well with shear and bezier warp tools

There might be something similar in avisynth, use search terms like warped frame, perspective, shear, and you might have better search results than "leaning"

Asmodian · 25th October 2011, 18:25

Reform looks very impressive, it should work if it is the entire frame. From the screen shots I think the entire frame might be distorted but I cannot be sure. If it is only moving objects then it could be much more complicated.

jmac698 · 25th October 2011, 19:01

It does look suspicious. The background doesn't seem to have the problem, in which case it could be like shutter roll. In that case it's related to the movement, so it's not easy to fix.

StainlessS · 25th October 2011, 22:29

Quote:

Originally Posted by EuropeanMan

Some of those same films released THROUGH EROS had those same people standing up straight.

Might be advantageous if we could see similar frames of those invididuals that lean one way or another, compared to the fine upstanding folk.

Edit: The above would seem to be post production and rule out anything related to movement during capture.

poisondeathray · 25th October 2011, 22:32

Quote:

Originally Posted by jmac698

It does look suspicious. The background doesn't seem to have the problem, in which case it could be like shutter roll. In that case it's related to the movement, so it's not easy to fix.

The background does have problem. If you look at the palm trees behind the girl's right in the 1st picture and the ship anchor in the 2nd picture, both are skewed . I would use the ship anchor as a vertical reference object to determine how much to correct

Also, he said it's consistent all the way through the movie in the 1st post , which implies a transfer issue

Pretty easy to fix with the vdub perspective plugin, or at least improve dramatically if it's constant. Otherwise you could keyframe the correction in something like after effects .

StainlessS · 25th October 2011, 22:49

Quote:

Originally Posted by poisondeathray

the ship anchor in the 2nd picture, both are skewed . I would use the ship anchor as a vertical reference object to determine how much to correct

You cannot assume anything from the angle of the ships anchor,
a little strain on an anchor chain is not unusual.

EDIT: One thing to note is the disparity in angle between the two samson posts (masts) on the ship.

poisondeathray · 25th October 2011, 22:56

Quote:

Originally Posted by StainlessS

You cannot assume anything from the angle of the ships anchor,
a little strain on an anchor chain is not unusual.

True, but correlate that observation with the angle of metal pillar beside the guy with the dark blue shirt (he's cut off in the background). Unless the ground is uneven there.... To me, the angle is very similar . IMO, this rough angle correction isn't worse that the original . I'm sure he can tweak it better, & crop & resize if he spends more time

The vdub plugin only allows for 4 point correction. It's not a mesh filter that allows for disproporational distortions. AE has several warp filters that can correct for more complex distortions and affect different parts of the frame, but I think you can get away with the vdub plugin only in this case, but he would have to correleate with other objects and other scenes to fine tune the correction

18th October 2011, 16:14	#1 \| Link
EuropeanMan Registered User Join Date: Nov 2006 Posts: 660	Frame correction for LEANING DEi was a manufacturer of many Bollywood DVD9s in the 80s/90s timeframe. The problem with them is that MANY of their prints were messed up. I wish I had a DVD9 to take a screenshot from. (Currently away from home) Basically the problem is this: If I were to take a picture of someone. You'd see them standing up straight. With DEi, that same person would lean one way about 5 to 10 degrees. So this LEANING was consistent ALL the way through the movie. EROS was primarily another manufacturer who hired DEi to make prints of their catalogue. Some of those same films released THROUGH EROS had those same people standing up straight. HOW did DEi mess this up? Why do their prints LEAN while EROS doesn't? On top of it, DEi was known to heavily crop their films from all 4 sides. VERY rarely did they release a movie where it wasn't cropped and had the original A/R intact. Is there ANY way to fix this, to get the frames BACK to lean the OPPOSITE way? I'd rather reAUTHOR my DEi titles because they are PROGRESSIVE, while EROS was always interlaced & badly on top of that... Thanks in advance... Last edited by EuropeanMan; 18th October 2011 at 16:18.

18th October 2011, 16:57	#2 \| Link
Ghitulescu Registered User Join Date: Mar 2009 Location: Germany Posts: 5,769	Probably a picture from one of their movies would explain better what you mean by "lean" __________________ Born in the USB (not USA)

20th October 2011, 17:09	#6 \| Link
Ghitulescu Registered User Join Date: Mar 2009 Location: Germany Posts: 5,769	Why don't we all wait for a sample instead of assuming things? __________________ Born in the USB (not USA)

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19th October 2011, 12:52	#3 \| Link
jmac698 Registered User Join Date: Jan 2006 Posts: 1,867	http://avisynth.org/mediawiki/SkewRows Or even try reform http://avisynth.org/vcmohan/Reform/Reform.html

19th October 2011, 21:58	#5 \| Link
IanB Avisynth Developer Join Date: Jan 2003 Location: Melbourne, Australia Posts: 3,167	@Bloax, That is a classic example of row skewing. The right and left sides of the image being stitched 1 pixel further across as you scan from bottom to top is the key hint. SkewRows(1) is designed to fix exactly this. The true width should have been 1367 not 1366. Unfortunately the last 768 pixels from the end of the top row will be missing. ____________________ I suspect EuropeanMan's problem is going to be skewing due to a fast shutter speed being used with a slow vertical blind style shutter, i.e. shutter is made from 2 blinds, 1st blind starts a down sweep exposing the film maybe taking 1/30th second to complete, the second blind follows close behind the first, maybe 1/250th second later, ending the exposure. So although the exposure time is 1/250th second the bottom of the negative is exposed 1/30th second after the top so things that move horizontally during this time become skewed in the final image. This shutter design was common for 35mm SLR type of still cameras, but I am not aware of this design being used in movie cameras. I guess when EuropeanMan posts a still we can stop guessing. SkewRows can quickly adjust for only integer pixel skewing. Reform will more likely be required for the fractional shift needed. The hard bit is going to be the motion tracking, still image elements won't be skewed.

21st October 2011, 04:44	#7 \| Link
EuropeanMan Registered User Join Date: Nov 2006 Posts: 660	Arghhhh I had totally forgotten about my thread...so so sorry... here's an example from one particular DEi title: Khal Nayak (1993)

21st October 2011, 05:03	#8 \| Link
EuropeanMan Registered User Join Date: Nov 2006 Posts: 660	^ this is a PRIME example...

21st October 2011, 05:08	#9 \| Link
EuropeanMan Registered User Join Date: Nov 2006 Posts: 660	I also realise that IF there was a way to fix this, I'd have to crop on both sides just to get the main part of the frame "perpendicular" so to speak. Each side's corner/triangle would then be gone...

22nd October 2011, 08:40	#10 \| Link
manono Moderator Join Date: Oct 2001 Location: Hawaii Posts: 7,406	If you just want to rotate it a little bit clockwise, then Fizick's Rotate filter is what you want: http://avisynth.org/warpenterprises/ Rotate(1.5) rotates it one and a half degrees clockwise. And as you said, you'll have to crop and resize.

22nd October 2011, 13:09	#11 \| Link
jmac698 Registered User Join Date: Jan 2006 Posts: 1,867	It's not a rotation, you need reform.

24th October 2011, 05:17	#12 \| Link
EuropeanMan Registered User Join Date: Nov 2006 Posts: 660	^ could you please elaborate on REFORM? thanks

24th October 2011, 21:27	#14 \| Link
poisondeathray Registered User Join Date: Sep 2007 Posts: 5,371	Another option is vdub's perspective filter , or use batch image processing as stills like photoshop gimp's shear filter . You can fix it quite easily in after effects as well with shear and bezier warp tools There might be something similar in avisynth, use search terms like warped frame, perspective, shear, and you might have better search results than "leaning"

25th October 2011, 18:25	#15 \| Link
Asmodian Registered User Join Date: Feb 2002 Location: San Jose, California Posts: 4,407	Reform looks very impressive, it should work if it is the entire frame. From the screen shots I think the entire frame might be distorted but I cannot be sure. If it is only moving objects then it could be much more complicated.

25th October 2011, 19:01	#16 \| Link
jmac698 Registered User Join Date: Jan 2006 Posts: 1,867	It does look suspicious. The background doesn't seem to have the problem, in which case it could be like shutter roll. In that case it's related to the movement, so it's not easy to fix.