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View Full Version : how to find best cropped frame placement inside letterboxed version


spoRv
30th May 2017, 18:22
Here I am with another impossible task for our gurus! :D

There is a mainly pan&scan version of a letterboxed movie, with few open matte shots.

As this version quality is inferior to the BD, I'd like to use only open matte shots untouched, while using the BD, cropped and upscaled, to recreate the rest of the movie.

The cropped frame is included in the letterbox version; most of the time it's dead center, but often it is placed on the left or the right, in different places. No pan&scan occurs, the placement doesn't change inside a single shot.

So, my request is: given the two images C (cropped) and L (letterbox), is it possible to know where C is located inside L?

To reduce computation time, I thought it could be better, instead compare every single frame, that the script would locate first frame for every shot change, then make a comparison between C and L, and find the corresponding left and right crop values - or, at least, find the most similar to a given number of crop settings.

Result should be a list of frames (first, last) with cropping values (L would suffice, as cropped frame width is always the same), or crop setting number.

Well, if someone has read until here, he deserves an example:

https://s20.postimg.org/hgcvo6t3h/cropped_frame_location.jpg

I produced 11 crop settings (L5...L1,center,R1...R5, first row) and overlaid each to the cropped version (second row), with subtract mode (third row) and difference (fourth row); as you can see, the first frame is dead center, second is L2, while third has no correspondence, as it is an open matte shot.

I'm pretty sure there is a solution, but far from my skill...

Katie Boundary
31st May 2017, 21:04
So... the Blu-Ray version applied tilt-and-scan to the scenes that were open-matte in the other version?

https://s14-eu5.ixquick.com/cgi-bin/serveimage?url=http:%2F%2Forig07.deviantart.net%2Fe6f4%2Ff%2F2012%2F154%2F8%2Fb%2Fyou_bastards_by_brilliantbastard-d526qfg.png&sp=7a31e679cfd4bf406757ac19bbef3445

spoRv
31st May 2017, 21:15
We are talking about a whole movie saga that I can't disclose the title - let's say it includes 8 films...

Well, there are 16:9 fullscreen versions broadcasted; I say fullscreen because they include open matte shots - where blu-ray (and dvd) has more details on both sides, but less on top and bottom - and cropped shots (not pan&scan), where the fullscreen is just the blu-ray (dvd) image cropped on both sides (placement varies by shot, but not within the shot itself, hence is not technically pan&scan); often this cropped shots contain a bit more details on top and bottom. AFAIK no tilted scan in blu-ray (dvd) for open matte shots.

I can say this: I'm in favour of OAR, of course, but watching these movies in open matte is very rewarding - consider the fullscreen version just an alternative. A nice one! :D

wonkey_monkey
1st June 2017, 00:05
We are talking about a whole movie saga that I can't disclose the title - let's say it includes 8 films...


Ooh, such mystery. Though you probably shouldn't have posted screenshots of this mysterious movie saga if you didn't want people knowing which one it was.

spoRv
1st June 2017, 10:37
I'm not a wizard, but I tried to make some magic to solve this problem... thought to use some modified frame removal script, without success...

So, I ended up to follow my own idea, but with 15 positions instead:

https://s30.postimg.org/6erjcowxd/cropped_frame_location2.jpg

All manual, but sped up a bit the task... if only I know a spell to do that automagically... :D

Katie Boundary
8th June 2017, 08:41
16:9 fullscreen

dafuq?

spoRv
8th June 2017, 14:00
Mainly open matte, but there is an episode that is all cropped (with a bit more details on top and bottom), and another with about 17% open matte and rest cropped (with less details on top and bottom); that's the one I've worked on. By the way, manual cropping is ended - it took several hours, though...