Special Resize back to 4:3

[henryperu77]

Hi

I have this HD capture of a SD video, but it was streched to 16:9 , when i resize back to 4:3 the image is distorsed , what method of resize should i use to do it corrrectly

HD
https://preview.ibb.co/cJJr0p/ufo_16x9.jpg (https://ibb.co/kmqh6U)


Original 4x3 SD
https://image.ibb.co/eDG0t9/ufo_4x3A.jpg (https://ibb.co/doOPLp)


HD resized to 4x3
https://preview.ibb.co/kAktD9/ufo_16x9_resize.jpg (https://ibb.co/f16N6U)


Any help is apreciated!

[kgrabs]

Maybe Debicubic or Debilinear? https://forum.doom9.org/showthread.php?t=174846

Edit: 16:9 version is 640x360, original is 640x480, there's really no way to regain lost information or undo downscaling

[henryperu77]

is kinda a progressive stretching <-----.----->

[FranceBB]

They screwed up.
That's definitely a 720x576 50i anamorphic SD TX Master.
When it goes on air in an HD channel, the playout port that plays the content reads the flag, which can be either 4:3 or 16:9 and resizes it to HD accordingly.
It seems that nobody checked the flag and it went on air terribly wrong: the playout port interpreted it as 720x576 flagged 16:9 and simply upscaled it to HD, ending up with the wrong aspect ratio and displaying black borders with inactive lines. Luckily they are outside the safe area, but still...
If something like this goes on air where I work, the encoder who didn't check it would probably be fired along with the playout operator who didn't report anything and just let it go on air like this.

Anyway, back to your question, just crop a little more after the black borders with the inactive lines and you'll get the same AR you have in the original picture:

ImageSource("ufo_16x9.jpg")

Crop(50, 0, -50, -0)

Spline64Resize(640, 480)

https://i.imgur.com/MPUae2j.png

Original uncropped:

https://image.ibb.co/eDG0t9/ufo_4x3A.jpg


Anyway, this is definitely an SD TX Master upscaled by the playout port 'cause you can see raimbowning and dot crawl at the bottom, where there's the caption.
To get rid of them you could try to use

#for raimbowning
ChubbyRain2(th=10, radius=10, show=false, sft=10, interlaced=false)

#for dot crawl
LUTDeCrawl(ythresh=10, cthresh=10, maxdiff=80, scnchg=100, usemaxdiff=true, mask=false)

[Ghitulescu]

Maybe they broadcast the 4:3 flag too (and letting the STB do the proper display) which flag was lost during (user-side) computer conversion. I don't know whether it's exactly the same situation, but this happened a lot in the past with people that processed the VOB files from a DVD ignoring the AR flag in the IFOs.

Anyway, I think the original material should be 480i, for it originates from USA, not 576i (Europe). I can imagine the first wrong decision has occurred somewhere else than at the time of broadcasting.

[johnmeyer]

If the "original 4:3" truly is the original, and if it is the same frame, then the 16:9 version has been cropped. Note the painting on the wall to the left top of her head, and her jewelry around her neck. The 16:9 version clearly shows the the image was cropped. Therefore, any simple re-size will fail. What' you'll need to do instead is re-size back to 4:3 using a different re-size amount, and then accept that you'll have some black bars.

The top/bottom cropping is very typical of shows that have been re-scanned to 16:9 from 35mm. I don't know if that is what is going on here, but you can look up "Seinfeld" to find out how they managed to create 16:9 from a show that was originally broadcast in 4:3. It turns out that the 35mm cameras they used to film the shows were typical movie cameras and therefore recorded the scenes in something approaching, but not quite achieving, 16:9. So to get to true 16:9, they scanned the full width of the film, but then cropped the top and bottom slightly, moving that crop, as needed, to frame the action as best they could, somewhat like the "pan & scan" transfers of widescreen movies was done when they were broadcast in 4:3 without letterboxing.

[henryperu77]

Ok i will try to crop a little more

[poisondeathray]

You can use warpedresize (part of simpleresize.dll) to perform non linear resizing

eg.
WarpedResize(960,720,1.1,1)
https://s22.postimg.cc/xo5clagnl/warpedresize.jpg

You can play with the hwarp parameter to get it the way you want

[henryperu77]

You can use warpedresize (part of simpleresize.dll) to perform non linear resizing

eg.
WarpedResize(960,720,1.1,1)
https://s22.postimg.cc/xo5clagnl/warpedresize.jpg

You can play with the hwarp parameter to get it the way you want

Thank you! thats what i wanted! :)