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Apple's slapdash approach to image processing

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Simon Ubsdell
Apple's slapdash approach to image processing
on Jan 15, 2014 at 8:54:31 pm

As I have pointed out here:

http://forums.creativecow.net/readpost/344/27093

... there is a really basic flaw in the way that the much-touted FCP X (and Motion 5) keyer handles the blur component of the light wrap function.



The more closely one looks at Apple's image processing offerings the less impressed one is likely to be.

it is very odd that the keyer, which in many respects is quite powerful, should exhibit such a schoolboy error.

It really does look as though the development team is a little short of qualified talent in some key areas. Or they are really hard pushed to get stuff out of the door without adequate QC.

Anyone with even a basic knowledge of compositing will know how embarrassing this mistake actually is.

Definitely symptomatic of a weakness in the development pipeline.

Simon Ubsdell
http://www.tokyo-uk.com


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Jeremy Garchow
Re: Apple's slapdash approach to image processing
on Jan 15, 2014 at 8:58:07 pm

I don't know how the keyer got so much hype to begin with.

Sure, it's convenient, it's fast, has some cool controls, it's fast, is fast, and it's fast, but I can't get more than a passing rough cut quality out of it.

But it is fast.

And fast.

Jeremy


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Simon Ubsdell
Re: Apple's slapdash approach to image processing
on Jan 15, 2014 at 9:06:27 pm

Quite so.

Yes, it's very fast, but I've read countless comments about how it's so much better than Keylight, for example!

It's very handy if you need a quick result that looks OK, but otherwise it's not really much use.

All that said, the point is that no-one at Apple (even after all this time) spotted a really obvious and easily avoided error!

What does that say about their attitude to image processing in general?

Discuss.

Simon Ubsdell
http://www.tokyo-uk.com


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Jeremy Garchow
Re: Apple's slapdash approach to image processing
on Jan 15, 2014 at 9:12:40 pm

[Simon Ubsdell] "What does that say about their attitude to image processing in general? "

Fix it in post?


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Simon Ubsdell
Re: Apple's slapdash approach to image processing
on Jan 15, 2014 at 9:15:01 pm

I should add that their Unsharp Mask filter in Motion 5 (not available in FCP X for some odd reason) exhibits the same error.

Shoddy quality control ... or is it ineptitude?

Simon Ubsdell
http://www.tokyo-uk.com


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Jeremy Garchow
Re: Apple's slapdash approach to image processing
on Jan 15, 2014 at 9:24:07 pm

[Simon Ubsdell] "Shoddy quality control ... or is it ineptitude?"

I don't think it's ineptitude, necessarily. I do think quality control and probably sample size is lacking. It's the same as it's always been with FCPX. Some things are amazing, some are not so amazing. It takes a while for programs to mature, especially when we have had such a performance increase and gut rehab of an already new system. It seems that Apple is doing this across the board. They are preparing for some sort of future by rewriting and stripping down all of their applications. Pages, their word processor, is kind of bad.

Not that this correlates, but there's even typos in the keyboard shortcut editor:



Jeremy


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Bill Davis
Re: Apple's slapdash approach to image processing
on Jan 15, 2014 at 9:26:51 pm

I suspect it's the Costco effect in action.

The sweet spot is 80% of the quality for 40% of the price. That drives success most often, methinks.

In keying, doesn't edge detection and light wrap involve pretty massive numbers of pixel calculations in a universe of rapidly increasing raster sizes? Particularly when those edges are in motion? Given that X is raster independent and as happy to work with 4k as HD, at some point, aren't you chasing a massive amount of image processing to do this with high precision?

And if so, might one way not to bog down system performance - particularly in a world where there are a lot more laptops running this than well-stocked MacPros - wouldn't installing an 80% quality keyer be pretty smart - at least until the computational horsepower catches up?

I'm just surmising here, but it's easy to want high-end features in every area of the program - but given the level of smarts in the Apple organization, I wonder if this is an omission or a decision.

Then again, I'm not a raster processing expert in any way shape or form, so I could be TOTALLY wrong and it certainly could be just a plain old-fashioned screw up as Simon implies!

Personally, I'll still forgive them since X costs way less for the whole program than I paid for a one seat license of Ultimatte back in the day. ; )

YYM (certainly) V

Know someone who teaches video editing in elementary school, high school or college? Tell them to check out http://www.StartEditingNow.com - video editing curriculum complete with licensed practice content.


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Bret Williams
Re: Apple's slapdash approach to image processing
on Jan 15, 2014 at 9:53:39 pm

As Jeremy and I have both discussed in the past, key light is much better. I get amazing results with transparency of things like motion blur and intricate hair detail. With apples keyed, it appears amazing at first. As if it just needs a tweak to take it over the edge to a wonderful key. But no amount of tweaks work to get rid of the halo around motion blur or the harsh edge that exists around compared to keylight. I've found Apples keyer to be well suited to slow moving bald subjects. Of which I've had a few. The light wrap idea sounds great, but never looks anything but blurry. Probably for the reasons posted.


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Marcus Moore
Re: Apple's slapdash approach to image processing
on Jan 15, 2014 at 11:33:18 pm

I just hope everyone concerned has provided feedback to Apple to fix this.



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Simon Ubsdell
Re: Apple's slapdash approach to image processing
on Jan 15, 2014 at 11:35:00 pm
Last Edited By Simon Ubsdell on Jan 15, 2014 at 11:48:48 pm

[Bret Williams] "With apples keyed, it appears amazing at first. As if it just needs a tweak to take it over the edge to a wonderful key. But no amount of tweaks work to get rid of the halo around motion blur or the harsh edge that exists around compared to keylight. "

Indeed.

I think what we have here is yet another case of an Apple image processing offering that is just "good enough" but no better.

The reason I wanted to raise this issue here is that I think it bespeaks a certain development philosophy and attitude to the marketplace.

Good marketing (hey, have you seen the cool new keyer in FCP X!), less good delivery.



Simon Ubsdell
http://www.tokyo-uk.com


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Simon Ubsdell
Re: Apple's slapdash approach to image processing
on Jan 15, 2014 at 11:51:27 pm

[Bret Williams] "The light wrap idea sounds great, but never looks anything but blurry. Probably for the reasons posted."

Incidentally building a light wrap is really very straightforward.

It involves blurring the matte and then combining the blurred version with the original of the matte in order to create a edge that overlaps into the foreground. The amount of the blur determines the depth of the light wrap. This matte is then used to composite a blurred version of the background image back over the foreground.

This simulates the effect of the light from the background encroaching over the foreground edges as it does in the real world. It can really help a lot of green screen composites - but as with all things to do with keying it needs to be used with discretion.

The problem is that Apple haven't executed the blur properly so as to crop it at the edges of the frame - as I say, it's a really easy fix.

And pace Bill, not remotely computationally expensive.

Simon Ubsdell
http://www.tokyo-uk.com


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Jeremy Garchow
Re: Apple's slapdash approach to image processing
on Jan 16, 2014 at 1:35:46 am
Last Edited By Jeremy Garchow on Jan 16, 2014 at 1:54:01 am

It should be an easy fix, I agree, and light wraps are fairly easy as Simon mentions.

FCPX's Meyer* allows me to get looks approved more quickly than any other method at the moment.

I do love the speed, but I'd also like the quality when needed.

There are other facets of fcpx that combine the speed and quality, so hopefully Apple can focus on it at some point.

Simon, have you messed with fxplug3? Any better? Worse?

*keyer


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Walter Soyka
Re: Apple's slapdash approach to image processing
on Jan 16, 2014 at 2:47:18 am

[Simon Ubsdell] "It involves blurring the matte and then combining the blurred version with the original of the matte in order to create a edge that overlaps into the foreground. The amount of the blur determines the depth of the light wrap. This matte is then used to composite a blurred version of the background image back over the foreground... The problem is that Apple haven't executed the blur properly so as to crop it at the edges of the frame - as I say, it's a really easy fix."

As in, like, ticking a checkbox. The built-in M5 Gaussian blur already correctly supports "crop" (more accurately called "repeat edge pixels" in Adobe-land) -- but the blur used in the keyer (wrongly) does not make use of this.

To expand on Simon's explanation of the problem a little, think about what a blur does: it sets the value of each pixel in the image to a weighted average of that pixel and its neighbors over a specified radius. Therefore, edges are special case, as they don't have the same number of neighbors that an interior pixel has. You can't calculate these pixels unless you first expand the raster of the image so that it's large enough that the image's exterior pixels have the same number of relevant neighbors as the interior pixels.

But what's outside the edge of the image? You have to fill out from the edge pixels with something in order to calculate their blur, so you have to make an assumption. You can either pretend there's nothing out there (black), or you can pretend that the pixels at the edge extend outward to the edge of the blur radius. In other words, you have to enlarge the image by x pixels at each edge to perform a blur, where x equals the radius of the blur, and you have to fill in that area outside the original raster with something.

When you pretend there's nothing out there (black), you get a dark fringing around the edge of your frame when you blur, as if the edges are pulling in. When you extend the edge pixels outwards into the expanded blur raster, this does not occur.

A picture is worth a thousand words, so here are eight thousand words.

The red line shows the original raster of our image to blur -- a circle that extends beyond and is cropped by its raster. The area between the red and the green lines is where we are extending the raster, pre-blur. In this first example, these expanded bounds are filled with black:




Now, when we blur this, including the black expanded bounds, we get these edges that expand beyond our original raster, as well as these darker shadows from the blurred outer black bleeding into our original raster:



So we crop this down to our original raster, leaving this dark fringing inside our raster:



Now, if we want to avoid that fringing, we can simply copy the outer line through the expanded bounds, repeating the edge pixels outward, pre-blur:



Blurring this, we get:



And cropping that back to the original raster gets us this, with no incursion of black into the edge-touching areas:



Note that neither one of these is perfect. Nothing gets us back the original extents of the circle that were cropped from the original raster. That would look like this, if we could do it:






However, in the case of a blurred matte for a light-wrap, the second, edge-repeating set is more correct. Repeating the edge pixels acknowledges the fact that the edge-violating areas of the matte extend beyond the extents of the raster, whereas pretending that they end at the raster bounds is clearly incorrect.

And with that, I'll conclude this evening's image processing 101 lecture. Any questions?

Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog - What I'm thinking when my workstation's thinking
Creative Cow Forum Host: Live & Stage Events


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Jason Jenkins
Re: Apple's slapdash approach to image processing
on Jan 16, 2014 at 4:06:38 am

[Walter Soyka] "And with that, I'll conclude this evening's image processing 101 lecture. Any questions?"

101? I wish I could understand half of what you just said.

Jason Jenkins
Flowmotion Media
Video production... with style!

Check out my Mormon.org profile.


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Craig Alan
Re: Apple's slapdash approach to image processing
on Jan 16, 2014 at 5:12:33 am

It's simple really. You put a round peg in a square hole. Think different.

Mac Pro, macbook pro, Imacs (i7); Camcorders: Panasonic AG-HPX170/AG-HPX250P, Canon HV30/40, Sony Z7U, VX2000, PD170; FCP 6 certified; write professionally for a variety of media; teach video production in L.A.


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Walter Soyka
Re: Apple's slapdash approach to image processing
on Jan 16, 2014 at 1:41:49 pm

[Jason Jenkins] "101? I wish I could understand half of what you just said."

Then I didn't do it right. I'll come back with a better explanation after I have a few minutes to draw up some new illustrations.

Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog - What I'm thinking when my workstation's thinking
Creative Cow Forum Host: Live & Stage Events


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Herb Sevush
Re: Apple's slapdash approach to image processing
on Jan 16, 2014 at 2:37:02 pm

[Walter Soyka] "Then I didn't do it right. I'll come back with a better explanation after I have a few minutes to draw up some new illustrations."

It was a excellent explanation, the guys were just having some fun with you I do believe, although I'm not at all opposed to you coming back with more. Thanks for posting.

Herb Sevush
Zebra Productions
---------------------------
nothin' attached to nothin'
"Deciding the spine is the process of editing" F. Bieberkopf


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Jason Jenkins
Re: Apple's slapdash approach to image processing
on Jan 16, 2014 at 6:41:32 pm

[Walter Soyka] "Then I didn't do it right. I'll come back with a better explanation after I have a few minutes to draw up some new illustrations."

Please don't put yourself out any more for me, Walter. I'm stretched pretty thin and I'm sure the problem is just my brain :)

Jason Jenkins
Flowmotion Media
Video production... with style!

Check out my Mormon.org profile.


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Simon Ubsdell
Re: Apple's slapdash approach to image processing
on Jan 16, 2014 at 2:29:02 pm

Outstanding as always! Great explanation. And pictures too ;-)

Simon Ubsdell
http://www.tokyo-uk.com


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Aindreas Gallagher
Re: Apple's slapdash approach to image processing
on Jan 16, 2014 at 10:09:30 pm

walter, you are a mad scientist. so is ubsdell at that.

you'd suspect that between the pair of you, as an IQ, there is a really, really good bowling score.

http://vimeo.com/user1590967/videos http://www.ogallchoir.net promo producer/editor.grading/motion graphics


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Herb Sevush
Re: Apple's slapdash approach to image processing
on Jan 16, 2014 at 10:30:45 pm

[Aindreas Gallagher] "between the pair of you, as an IQ, there is a really, really good bowling score."

Leave it to the Cow's poet laureate Aindreas to link, if only literarily, bowling and intelligence. Lovely. And Franz worries that women don't want to come to this fine pasture. I propose a new forum name - "FCPX - a poetic inquiry into the madness of NLE design." That ought to pack them in.

Herb Sevush
Zebra Productions
---------------------------
nothin' attached to nothin'
"Deciding the spine is the process of editing" F. Bieberkopf


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Walter Soyka
Re: Apple's slapdash approach to image processing
on Jan 17, 2014 at 7:04:07 pm
Last Edited By Walter Soyka on Jan 17, 2014 at 7:04:40 pm

Thank you for the kind words, Aindreas.

[Aindreas Gallagher] "walter, you are a mad scientist."

This is absolutely going on my business card now.

Walter Soyka
Designer & Mad Scientist at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog - What I'm thinking when my workstation's thinking
Creative Cow Forum Host: Live & Stage Events


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Bill Davis
Re: Apple's slapdash approach to image processing
on Jan 18, 2014 at 1:01:58 am

[Walter Soyka] "Thank you for the kind words, Aindreas.

[Aindreas Gallagher] "walter, you are a mad scientist."

This is absolutely going on my business card now."


I'm seeing a photo change featuring a white lab coat and a couple of Thunderbolt cables draped into a stethoscope type arrangement?

Know someone who teaches video editing in elementary school, high school or college? Tell them to check out http://www.StartEditingNow.com - video editing curriculum complete with licensed practice content.


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Jack Zahran
Re: Apple's slapdash approach to image processing
on Jan 22, 2014 at 10:57:31 pm

So what you are looking for is a check box to repeat screen edge pixels, so the mask will be be outside the screen edge and not blur the side(s) your masking when the respective side(s) mask intersects with any screen edge?

AE has the repeat edge pixels checkbox. You're looking for something similar?


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Charlie Austin
Re: Apple's slapdash approach to image processing
on Jan 16, 2014 at 5:07:01 am

[Simon Ubsdell] "The problem is that Apple haven't executed the blur properly so as to crop it at the edges of the frame - as I say, it's a really easy fix."

I've actually seen the same thing, (blur at the frame edges) when applying say, gaussian blur to a selected area of a picture in apps like Graphic Converter. The blur is applied only to the selection, but the edges get it too. I wonder if it's an FCP X problem, or a problem with one of the OS X frameworks? Either way, they oughta fix it...

-------------------------------------------------------------

~ My FCPX Babbling blog ~
~"It is a poor craftsman who blames his tools."~
~"The function you just attempted is not yet implemented"~


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Walter Soyka
Re: Apple's slapdash approach to image processing
on Jan 16, 2014 at 1:45:47 pm

[Charlie Austin] "I've actually seen the same thing, (blur at the frame edges) when applying say, gaussian blur to a selected area of a picture in apps like Graphic Converter. The blur is applied only to the selection, but the edges get it too. I wonder if it's an FCP X problem, or a problem with one of the OS X frameworks? Either way, they oughta fix it..."

Both edge-handling options for blurs are already implemented -- look at the "Crop" checkbox on the Gaussian blur, for example. It's just that the keyer uses the wrong option.

Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog - What I'm thinking when my workstation's thinking
Creative Cow Forum Host: Live & Stage Events


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Jeremy Garchow
Re: Apple's slapdash approach to image processing
on Jan 16, 2014 at 2:09:31 pm

At the very least, you can build your own light wrap in FCPX and have control over the blur and intensity. This is obviously a bit much for a light wrap, but I made it so we can see it.

I still don't like hat FCPX does to all edges of a key. For me, a key is all about the edges.

Here's what it looks like (image):



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Simon Ubsdell
Re: Apple's slapdash approach to image processing
on Jan 16, 2014 at 2:28:04 pm

That's neat :)

If we just had the Motion Channel Mixer filter (and a Dilate/Erode option, as in the Motion MinMax filter) in X there's a lot more one could do with building custom keyer components.

As you say, the built-in keyer gives some pretty nasty edges - and there's nothing you can do to fix it.

Simon Ubsdell
http://www.tokyo-uk.com


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