ADOBE PREMIERE PRO: Tutorials Forum Articles Creative Cloud Debate

Premiere Pro Editing - Scaling, Resizing, Zooming and Resolution Loss of Footage Clips

COW Forums : Adobe Premiere Pro

<< PREVIOUS   •   FAQ   •   VIEW ALL   •   PRINT   •   NEXT >>
Devinda FernandoPremiere Pro Editing - Scaling, Resizing, Zooming and Resolution Loss of Footage Clips
by on Feb 20, 2015 at 3:29:45 am

Adobe Premiere's basic scaling function allows you to zoom in on a Clip upto 600% - but at what percent increase in the size of a 1920x1080 clip do you start to loose resolution?

I was told you could scale up about 10-15% without any visible or noticeable loss in resolution? First of all - Is this true? And secondly, is there a more scientific and accurate percentage you can increase the size of your footage without losing any resolution - on the pixel level?


Return to posts index

Tero AhlforsRe: Premiere Pro Editing - Scaling, Resizing, Zooming and Resolution Loss of Footage Clips
by on Feb 20, 2015 at 5:33:14 am

All of that depends on the footage you are scaling. If it's nice, clean uncompressed footage it will probably scale better than compressed, blocky webvideo.


Return to posts index

Devinda FernandoRe: Premiere Pro Editing - Scaling, Resizing, Zooming and Resolution Loss of Footage Clips
by on Feb 20, 2015 at 6:40:00 am

I'm shooting using a Canon 5D MK III on the 1920x1080 ALL-I setting. The codec is H.264. in the .mov or mp4 container.

Does anyone know how the scaling/zooming is handled by the software? i.e - if for example the zoom is 100% then am I to assume that the software doubles the number of pixels of the frame: 1080 x 1920 = 2 Million Pixels (approx) and thus a 100% scale would double the pixels to 4 Million Pixels and therefore resolution would be reduced to 50% of the original?

Am I making any sense on this?


Return to posts index


Tero AhlforsRe: Premiere Pro Editing - Scaling, Resizing, Zooming and Resolution Loss of Footage Clips
by on Feb 20, 2015 at 7:28:42 am

If you scale full HD up by 100 percent it actually quadruples the pixel count to 3840x2160.


Return to posts index

Devinda FernandoRe: Premiere Pro Editing - Scaling, Resizing, Zooming and Resolution Loss of Footage Clips
by on Feb 20, 2015 at 7:40:13 am

*** If you scale full HD up by 100 percent it actually quadruples the pixel count to 3840x2160. ***

No it does not... you are confusing 4K footage (which is 3840x2160 pixels) with 2K being scaled by 100%...


Return to posts index

Tero AhlforsRe: Premiere Pro Editing - Scaling, Resizing, Zooming and Resolution Loss of Footage Clips
by on Feb 20, 2015 at 9:25:46 am

If you make a UHD timeline and insert HD footage the footage will fit to the comp when it's scaled up 100%.

1920*1080=2073600
3840*2160=8294400

8294400/2073600=4


Return to posts index


Devinda FernandoRe: Premiere Pro Editing - Scaling, Resizing, Zooming and Resolution Loss of Footage Clips
by on Feb 21, 2015 at 3:31:22 am

Ah Ok... I see what you are saying... the Adobe Premiere's Software calibration of "100%" means that it actually quadruples the size of the image... (like with 720p which is approx 900K pixels when scaled up to 1080 is said to be a 50% increase).

I was referring to the actual standard definition of up-scaling to 100% (as in, doubling the size).


Return to posts index

Blaise DourosRe: Premiere Pro Editing - Scaling, Resizing, Zooming and Resolution Loss of Footage Clips
by on Feb 20, 2015 at 11:26:52 pm

It all depends on how you're mastering. Are you going out to 1080P? Then be really careful--that 10-15% number is a bit high, in my completely unscientific and unsupported personal opinion, I wouldn't go any higher than 10%, otherwise it gets pretty noticeable.

Are you mastering to 720P? Then you've got a little room to play around. If mastering to 720P, theoretically you can zoom in to 150% and not lose resolution. The key to this is to bring your 1080P footage into a 720P timeline--you have to reduce it in size by 66% to fill the screen, but if you don't, you'll already be zoomed in at the max resolution, since the edges of the footage will be outside of your canvas. So: if you're scaling up in a 1080P timeline, and mastering to 720P, scale the footage up to 150%. If you're putting 1080P in a 720P timeline, it should come in already zoomed in, or you can reduce it down to a maximum of 66%.

Mastering to 480P SD? You can zoom in by like, 200, 250% easily.

Mastering to a 360x270 animated GIF? It's your birthday, and you should thank Eddie the Editor, God of Post Production, for his many blessings. Zoom in as far as you damn well want.

Now, if the question you're asking is "can I uprez 1080P footage to 4K without losing detail," the answer is, objectively, no. However, you have to sit reeeeeeally close to a big monitor to see the difference between 4K and HD--I believe Fast and Furious 6, or whatever the latest installment was, used DSLRs as crashcams and mixed quick shots into the regular 4K stuff. As long as you don't linger on the uprezzed stuff, it should be OK.


Return to posts index

Devinda FernandoRe: Premiere Pro Editing - Scaling, Resizing, Zooming and Resolution Loss of Footage Clips
by on Feb 21, 2015 at 3:41:57 am

Hi Blaise,

I am outputting to the same size (1080) that it was taken on the cam, so just wanted to know the limits of how much I can push the zoom and crop on a clip without losing any resolution. I have as a practice, been also avoiding zooming in more than 10%, but was hoping to find out a more scientific or mathematical understanding of what goes on when the software zooms in on the footage.

In practice, I have on rare occasions zoomed in up to 100% on some projects for clients and they have not noticed any difference in the resolution - most likely because, like most lay people, they really would not have a trained enough eye to know the difference - but it would be good to know the exact science behind it.

I guess it all boils down to how the software actually manipulates the clip on a pixel level... or maybe even the codec level?


Return to posts index


Blaise DourosRe: Premiere Pro Editing - Scaling, Resizing, Zooming and Resolution Loss of Footage Clips
by on Feb 26, 2015 at 12:34:23 am

Gotcha. The best person to answer this would be one of the Adobe guys (are you reading this, Todd Kopriva?), but from what I understand, it basically works something like this (and I apologize if this is overly basic or if you already understand how this works):

When you have a 1920x1080 clip on a 1920x1080 canvas, the pixels are represented on a 1:1 basis. When you scale it up, you of course lose some pixels to cropping, but the ones that remain present are subsampled across the 1920x1080 canvas. Let's use a single black pixel on a white surface as our clip example: when you increase the size of the clip by 200%, that single black pixel would be subsampled across four canvas pixels (not two, because remember it doubles in both x and y dimensions). Now you have four black pixels on a white field.

This is why resolution loss becomes obvious pretty quickly--when you double the size to 200%, you're not actually cutting your onscreen pixels in half--you're cutting them down to a fourth.

Now, let's say we didn't scale that image up by 200%, but by only 150% (100% is the native size of the clip). Theoretically, that black pixel is scaled up to the size of two pixels; but it's not that simple, because the size increases in both x and y dimensions. That means that those four pixels that showed black are going to have to try to represent only part of that two-pixel black dot. So depending on that dot's position, you might have one central black pixel with the ones around it registering grey as a transition, or maybe four pixels showing dark grey. This process is called interpolation, and there are different algorithms that can be used for different results. Basically, it's the software trying to average out the values for each pixel, based on what's around it.

Of course, the other factor that we're not taking into account is the quality of your initial footage. Super clean, 4:4:4 ProRes is going to look a lot different than highly compressed 4:2:0 DSLR footage, which loses some detail to compression. Highly compressed footage introduces additional artifacts that reduce your resolution in a different way--by decreasing the amount of information in the frame. So uncompressed footage is going to hold up to your scaling a lot better than compressed footage will.

So, I suspect that the answer to your question of "is there a hard limit" is...it depends. Depends on the footage, the subsampling algorithm that the NLE is using, and depends on how much you want to scale it up. Like I said, with AVCHD footage, I can usually get away with 10%.

Don't you love it when the answer is "it depends?" I sure do :) But knowing about all the factors definitely helps when making an educated guess.


Return to posts index

Devinda FernandoRe: Premiere Pro Editing - Scaling, Resizing, Zooming and Resolution Loss of Footage Clips
by on Feb 26, 2015 at 3:03:08 am

Wow, that was a Fantastic explanation (assuming its all true)... Thank you.

***when you increase the size of the clip by 200%, that single black pixel would be subsampled across four canvas pixels (not two, because remember it doubles in both x and y dimensions). Now you have four black pixels on a white field. ***

That also explains the last guy’s point about why the Software’s scaling calibration quadruples the number of Pixels, and not doubles it, when it comes to increases of 100% in size.


*** This process is called interpolation, and there are different algorithms that can be used for different results....

Basically, it's the software trying to average out the values for each pixel, based on what's around it. ***

So sticking close to your example… if we had 4 Pixels on a white canvas and those Pixels were 2 x Red and 2 x Orange, then a scale up of 50% would cause the Software to interpolate those existing pixels and create two additional pixels (now total of 6 pixels), that were a cross between the two colors? Yes/no? So in essence, you would be left with 2 x Red, 2 x Orange, and 2 x Red-Orange crossbreed Pixels - am I understanding that correctly?

*** Of course, the other factor that we're not taking into account is the quality of your initial footage. Super clean, 4:4:4 ProRes is going to look a lot different than highly compressed 4:2:0 DSLR footage, ***

OK, that really cleared up another nagging question I had. But does H264 footage ‘JPEG’ an image? As in, when it compresses an image, does it block/lump similar or same color pixels together? Take for example your example: Instead of a black pixel on a white canvas, lets assume that the pixel is a square of 100x100 black pixels… does the H264 Codec then just create a mathematical representation of that entire square as a single X and Y coordinate and a single Color Space data point for all 10,000 pixels within that square? I guess what I’m trying to understand is how the actual ‘JPEGGING’ works in the compression?


*** Don't you love it when the answer is "it depends?" I sure do :) But knowing about all the factors definitely helps when making an educated guess. ***

No, No, I Love it… So I think I’ve learned some very important points from this:

So RAW footage (i.e. 4:4:4 ProRes) is actually far more detailed than .H264 compressed footage in terms of Pixels AS WELL AS Color Space, simply because the Pixels in H264 are ‘JPeged’ into groups to save space(Memory). So while the two images have the same Number Of Pixels on each frame, the RAW footage has more detail per pixel, whereas the H264 footage has created blocks of pixels of the same Color Space and thus lost a lot of detail.

So that being said would it be logical to assume that a RAW file, which if we take the example of REDCODE R3D (which is about 160GB per 1 hour of footage for 2K), when compared with H264, which is approx. 16GB for 1 hour of footage for 2K) – the comparable scaling for the R3D would be roughly 10 times that of the H264…? - Because the H264 has been already compressed to a tenth of the size of the RAW footage? So the visible resolution of up-scaling a RAW file to 100% of its original size, would have the same 'look' to the human eye, as H264 footage scaled by only 10%. Is that logical, or have I derailed?


Return to posts index

Tero AhlforsRe: Premiere Pro Editing - Scaling, Resizing, Zooming and Resolution Loss of Footage Clips
by on Feb 26, 2015 at 9:12:15 am

[Devinda Fernando] "(which is about 160GB per 1 hour of footage for 2K), when compared with H264, which is approx. 16GB for 1 hour of footage for 2K) – the comparable scaling for the R3D would be roughly 10 times that of the H264…?"

Well. No, because the size of the file doesn't matter in scaling. You might have 160 gigs of shitty, noisy, high ISO, maybe compressed (as it can be) RED footage that will look terrible when you scale it up and on the other hand you have 16 gigs of well compressed (by the footage's terms) H264 that will look pretty nice even if you scale it up a bunch.

You can get all mathematical on this but the best way to scale footage is scale it to the point where it still looks good to you or the client. If it looks terrible then don't scale it that much.


Return to posts index


Devinda FernandoRe: Premiere Pro Editing - Scaling, Resizing, Zooming and Resolution Loss of Footage Clips
by on Feb 26, 2015 at 11:16:37 am

Well you certainly have a point about Noise, but I was trying to compare Apples to Apples here... That's why I said 160GB of 1 hour of footage for each scenario... So assuming proper lighting and no Noise, then would that be the case, or does higher ISO automatically translate into less detail in the image?


Return to posts index

Richard HerdRe: Premiere Pro Editing - Scaling, Resizing, Zooming and Resolution Loss of Footage Clips
by on Feb 26, 2015 at 4:46:00 pm

To interlope quickly, this is the a great article: https://library.creativecow.net/galt_john/John_Galt_2K_4K_Truth_About_Pixel...


Return to posts index

Devinda FernandoRe: Premiere Pro Editing - Scaling, Resizing, Zooming and Resolution Loss of Footage Clips
by on Feb 27, 2015 at 4:27:49 am

Fantastic article Richard... Thanks for sharing... it will probably take me a week or more to actually digest all that info in there as its quite complicated and more scientific than I am used to.


Return to posts index


Richard HerdRe: Premiere Pro Editing - Scaling, Resizing, Zooming and Resolution Loss of Footage Clips
by on Feb 27, 2015 at 5:04:52 pm

No problem. I've read it dozens of times and still find new and compelling information every single time. Here's more of the same






Return to posts index

Blaise DourosRe: Premiere Pro Editing - Scaling, Resizing, Zooming and Resolution Loss of Footage Clips
by on Feb 26, 2015 at 8:55:46 pm

Hah, thanks! I THINK it's true, at least from a perspective of a guy who is not a programmer or software engineer...just a longtime user!

Your summary is just about right. The only correction I'd point out is that compression in video is more tied up with changes to the frame over time, rather than jpeg-like blocks within the image (though there is some of that, too). With the All-I-Frame stuff you're working with, that's not an issue, but regular h.264 IPB compression hinges on key frames.

Think of it like this: a key frame is a fully detailed image, and then the compressor takes over and records the changes in the image for every frame since the key frame. So you have less information because it only stores data about what's different from the key frame. The amount of compression depends on how many key frames per second are being used; All-I-Frame compression has a key frame for every image, so it's less compressed. On the other end of the scale, when you compress something for web streaming, you can sometimes end up having a key frame only every 96 frames. You can see why the detail tends to break down a little.

There is, of course, compression on even the I-Frames of your DSLR footage--the color space is 4:2:0, for example, and it's 8-bit.

But the bottom line is that Tero's comment is right--your eye is a good indicator in a case like this. Civilians will usually not be as sensitive to these kinds of things, but sometimes not--my boss is not a videographer or photographer, but he's got a really good eye, even if he doesn't know the tech behind it.


Return to posts index

Devinda FernandoRe: Premiere Pro Editing - Scaling, Resizing, Zooming and Resolution Loss of Footage Clips
by on Feb 27, 2015 at 8:02:53 am

*** but regular h.264 IPB compression hinges on key frames. ***

Yeah, I know the mechanics of IPB, which is why I usually avoid using that setting. Actually the 2K RAW info is useful because I wanted to shoot a feature film, which would be shown on the Big Screen, which means I have to convert the finished product to 35mm film. For budget reasons I was hoping to get away with DSLR Equipment, but I think now after this discussion that it would be infinitely better to spend the extra money and go for the Red Camera equipment and get the 2K RAW output to work with. I would love to use 4K but my editing systems would just not be able to handle the size of the files. I was thinking about using 4K for some takes where it would save time by not having to take the Close ups and Mid shots because I could just pan and scan around the 4K frame in editing, and not lose any resolution on the final output .

Anyway this discussion has been most fruitful and I thank everyone for their input.

Cheers.


Return to posts index

Richard HerdRe: Premiere Pro Editing - Scaling, Resizing, Zooming and Resolution Loss of Footage Clips
by on Mar 2, 2015 at 9:33:06 pm

[Devinda Fernando] "Anyway this discussion has been most fruitful and I thank everyone for their input."

I would be remiss if I didn't stop you right here to ask "Why are you transferring to film?"


Return to posts index

Devinda FernandoRe: Premiere Pro Editing - Scaling, Resizing, Zooming and Resolution Loss of Footage Clips
by on Mar 3, 2015 at 1:51:46 am

Because the Movie Theaters in this country have Projectors that show film on 35mm reels.


Return to posts index

Richard HerdRe: Premiere Pro Editing - Scaling, Resizing, Zooming and Resolution Loss of Footage Clips
by on Mar 3, 2015 at 5:56:51 pm

How does theatrical distribution work in that country?


Return to posts index

Devinda FernandoRe: Premiere Pro Editing - Scaling, Resizing, Zooming and Resolution Loss of Footage Clips
by on Mar 4, 2015 at 1:54:02 am

Well, its a small island (Sri Lanka), and its a population of about 20 Million people. Around the country there are about 140-150 Film halls, and each one is part of 4 different main Circuits. Each hall usuallholds about 300-500 people. 3 of them are private and 1 is Government run... take a wild guess as to which one is the worst of them all? If you produce a film you would go with one of the main circuits which have about 30-70 theater halls attached. Most films go with about 35 theaters and run for about 50-100 days. For each Theater you want to screen in you have to produce a 35mm set of reels. That cost is one of most expensive costs of your overheads. Up until as recent as 5 years ago all Films here were shot on 35 mm cameras like the Arriflex 3,4, or 5. Then the Negative was developed in India and copies produced there, and then shipped back for screening. Now everything is shot on Digital - mostly Red cameras and then shipped to India for Reverse Tele-cine... and the then the reels sent back for screening. Though there is a guy here who does reverse Tele-Cine here on the island but he does not have a Tele-Cine machine... would you beleive he actually screens the digital footage onto a White projector wall, and re-records it on an Arriflex 35mm camera...then develops the negative and runs off the copies with that.


Return to posts index

Richard HerdRe: Premiere Pro Editing - Scaling, Resizing, Zooming and Resolution Loss of Footage Clips
by on Mar 4, 2015 at 4:26:17 pm

Wow that's crazy!

So if you show up with your film, they will screen it, no questions asked?

And really, there is a serious opportunity for you or someone to move to the DCI. http://www.dcimovies.com/


Return to posts index

Devinda FernandoRe: Premiere Pro Editing - Scaling, Resizing, Zooming and Resolution Loss of Footage Clips
by on Mar 5, 2015 at 12:51:25 am

Ha! There is usually a 6-12 month waiting list depending on the circuit. You have to pass the National Film corporation's utterly arbitrary and capricious Censor board... No swearing, or nudity, or homosexuality... unless its in a historical context...(whatever the hell that means???) And obviously no overt political attacks against the government... Also the previous govt didn't allow the display of Alcohol or Cigarettes, but all the previous films from 1940s to 1970s had this since they were a lot more lax on the issue... The equivalent of America's Pre-code era.
However, being that this is a Socialist Dicta... errr, ooops, I mean Socialist 'Democracy', ruled by the same group of Political Elite Families since Independence from the British in 1948... If you falter at the Govt level you can easily use Political influence and circumvent the system and even jump the waiting list line. If you have no political influence you can also bribe your way into it. This is not even a secret, in fact sometimes if you didn't bribe your way, and your film ended up sucking badly, you will be accused of bribery anyway...
There is no rule* that the film has to be in Sinhala (the Majority Language) but if its in English or Tamil you can't hope to recover your money since no one will go to see it. (Tamils are only 3 Million of the 20 Million) and while everyone here can speak English to some degree, the movie-going audience does not go to see English language films.
(* The Govt circuit only screens Sinhala or Tamil Films)


Return to posts index

Devinda FernandoRe: Premiere Pro Editing - Scaling, Resizing, Zooming and Resolution Loss of Footage Clips
by on Mar 5, 2015 at 1:13:36 am

Ha! There is usually a 6-12 month waiting list depending on the circuit. You have to pass the National Film corporation's utterly arbitrary and capricious Censor board... No swearing, or nudity, or homosexuality... unless its in a historical context...(whatever the hell that means???) And obviously no overt political attacks against the government... Also the previous govt didn't allow the display of Alcohol or Cigarettes, but all the previous films from 1940s to 1970s had this since they were a lot more lax on the issue... The equivalent of America's Pre-code era.
However, being that this is a Socialist Dicta... errr, ooops, I mean Socialist 'Democracy', ruled by the same group of Political Elite Families since Independence from the British in 1948... If you falter at the Govt level you can easily use Political influence and circumvent the system and even jump the waiting list line. If you have no political influence you can also bribe your way into it. This is not even a secret, in fact sometimes if you didn't bribe your way, and your film ended up sucking badly, you will be accused of bribery anyway...
There is no rule* that the film has to be in Sinhala (the Majority Language) but if its in English or Tamil you can't hope to recover your money since no one will go to see it. (Tamils are only 3 Million of the 20 Million) and while everyone here can speak English to some degree, the movie-going audience does not go to see English language films.
(* The Govt circuit only screens Sinhala or Tamil Films)

*** And really, there is a serious opportunity for you or someone to move to the DCI. http://www.dcimovies.com/**

I have been in talks with some business investors about Digital projectors and new movie halls, but they all think too small... their mentality is that the Film industry sucks, and in order to make money they should make smaller theaters - so instead of 300 seats to scale it down to 100 seats and equip them with digital Projectors. What they fail to realize is that the industry sucks because it has too much Govt intrusion, and restrictions, AND the movies that are being made SUCK BALLS... they are cringeworthy and utterly awful... and that's why no one goes to see them. So the first step in making the industry profitable and thriving is to create good content.
Most people (Producers) who make films here do it as some sort of Vanity project, where they get to sleep with a local famous Actress by bankrolling their next film. Some do it to launder money, you can get up to 35 Million Rupees tax free profits, No Questions Asked... which makes it a great Money laundering vessel for smugglers, drug dealers, and even government employees who get a lot of money in bribes.
The other major flaw in the system is that each theater only screens one Film at a time... and when you give your film for screening you sign a contract with the Circuit to run your film for a minimum of 50 days. So if your film ends up sucking balls, with in the first week theaters can be half empty and they play the projectors to empty film halls for upto a month sometimes. Very rarely do they yank the film from the halls so its just a huge waste of time and money for everyone. I have been banging my head on the table to get people who want to build theatres to make them larger.. or at the very least make them with multiple halls within a location, so that if one film fails then at least they can screen another at the same time and hopefully draw audiences that way... but sadly, like I said before... people think really small here, and don't want to invest the additional capital to 'Do it Right' the first time.


Return to posts index

Richard HerdRe: Premiere Pro Editing - Scaling, Resizing, Zooming and Resolution Loss of Footage Clips
by on Mar 5, 2015 at 5:28:19 pm

WOW! That is fascinating. Thanks for sharing :)

How do they handle the audio problem? Obviously if someone dirty transfers a movie the sync will suffer as well as the picture quality.


Return to posts index

Devinda FernandoRe: Premiere Pro Editing - Scaling, Resizing, Zooming and Resolution Loss of Footage Clips
by on Mar 5, 2015 at 9:23:56 pm

I'm not familiar with the methodology for the audio. But the theaters are such low quality here that everyone is used to it. Half of them don't even have AC, and the projectors are really old in the village areas so picture quality is not the utmost concern. In fact as of 2009 when the war ended, 40% of all the TVs in the country were still Black and White, - that has probably changed a lot but I don't know the new figures, being that this is the fastest developing country in Asia in the past 5 years.


Return to posts index

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
© 2017 CreativeCOW.net All Rights Reserved
[TOP]