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Blurring faces

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Sun, 06/21/2009 - 21:50
Jack
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Hi,

I need to blur a moving section of a clip, in this case faces. With the previous release i used obscure, which let you set a start point and an end point, and followed the region marked automatically. It didnt really work out, mainly because it didnt track the desired section well so i ended up with what should be blurred showing on several frames.

I cant make this work on the new release. Any suggestions on how to face blur using Kdenlive 0.7.3?

Thanks,

Jack

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Mon, 06/22/2009 - 04:51
#1
ddennedy
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Re: Blurring faces

Apply the Automask filter, adjust the rectangle, uncheck Debug, and check the Obscure checkbox.

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Mon, 06/22/2009 - 14:53
#2
jmpoure
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Re: Blurring faces

Also upgrade to Kdenlive 0.7.4.
Kdenlive 0.7.3 has many bugs and can be considered "deprecated".

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Mon, 06/22/2009 - 19:43
#3
Jack
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Re: Blurring faces

Thanks for the advice. I downloaded Kdenlive 0.7.4, havent tried it out much yet but looking forward to it greatly.

I dont have the Automask filter. Tried installing MLT 0.4.2.tar.gz following the instructions here:
http://www.kdenlive.org/user-manual/downloading-and-installing-kdenlive/...

seemed to work fine, but now I open kdenlive, load a clip, put it in the timeline and the whole thing immediately crashes. Terminal says:

KCrash: Application 'kdenlive' crashing...
sock_file=/home/jack/.kde/socket-dhcppc0/kdeinit4__0

Any further advice?

Thanks

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Tue, 06/23/2009 - 08:39
#4
jmpoure
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Re: Blurring faces

Compiling Kdenlive by hand is really difficult. If you experience crashes, I can only encourage you to use the builder wizard as it will fetch Kdenlive, MLT and FFMpeg from SVN.

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Wed, 07/01/2009 - 23:04
#5
Thomasso
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Re: Blurring faces

Hello all, I'm interested in this feature too as I would like have some of my subject incognito.

I'm running Kdenlive 0.7.4 on Ubuntu: 9.04 (Jaunty).

I do not see any of the icons or menus that you “ddennedy” listed. The closest thing to an auto mask feature is the “Obscure” video effect, and all I can do there is place the distorted box in one area of the screen for each segmented clip.

Because most of the people are walking, or moving through the shot, how would I be able to have a Obscure box track them without aid of keypoints?

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Wed, 07/01/2009 - 23:18
#6
ddennedy
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Re: Blurring faces

Well, Thomasso, you need the Auto Mask filter. Just because you do not have it does not mean it does not exist. It means that you do not have the MLT motion_est plugin or that it is failing to load. I do not just pull these answers out of my ass!

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Wed, 07/01/2009 - 23:38
#7
Thomasso
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Re: Blurring faces

Oh, I sincerely apologize if my query sounded derogatory—it was not intended to sound like that in the least bit. I assume that you do not pull your answers out form your ass either.

However, I do thank you for you information on pulgins. I did not know there were additional plugin needed for this. One final question, is this plugin found in the Ubuntu repositories? I don't think I have it, and I see no errors when Kdenlive loads—actually it is quit stable.

Thank you for your time.

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Fri, 07/03/2009 - 02:09
#8
ddennedy
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Re: Blurring faces

Currently, all MLT plugins come with MLT except when it needs to access external plugin systems like ladspa or frei0r. However, it is possible your distribution or the build process for some reason disable the motion_est plugin. Also, maybe if you use a language other than English it is called something other than "Auto Mask." To see if you have the plugin run 'locate libmltmotion_est.so' in a terminal window. If you have it, then it might fail to load because at one point that plugin was not told to link against the math lib, which some distributions require. This is fixed in the latest release.

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Wed, 08/26/2009 - 06:24
#9
x1250
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Re: Blurring faces

I'm having problems trying to move the blurred box around, or make it bigger if it needs to (dynamicly, change size in time, or position). I'm trying to follow a face that is moving around. Is this doable? How? Thanks =)

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Wed, 08/26/2009 - 09:20
#10
ddennedy
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Re: Blurring faces

At this time you can not manually adjust the rectangle over time. The Automask uses motion estimation algorithm to try to track the subject within the rectangle automatically. If you need to adjust this periodically, then you must split the clip at various critical points, apply the same effect to each segment, and then refine it by repeating the process.

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Fri, 09/24/2010 - 22:36
#11
Jack
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Re: Blurring faces

Hi all,

For some reason i simply cant install the automask. I have yet to become a competent Kdenlive & Linux user.

However I have found a really good workaround to blurring face.

Basically, using gimp i created a oval coloured shape on a transparent background. In Kdenlive place video to be blurred on track 2 and the transparent image on the track above it, normally 1. right click on the image and select 'add transition' then select 'composite'. extend the image and the transition to cover the required section of video.

If you click on the transition you get to edit it in the 'effect stack'. First thing you want to do is locate the two sliders beneath the 'effect stack' screen. There is a bar and a red slider above and a grey slider below.
Resize the image to your preference by amending it on the 'effect stack' screen, then move its position to cover the face at its initial position. move the grey slider to the point where the face has moved somewhat and move the red slider to that point. There are several buttons including one which says 'add keyframe' click it. then go to the 'effect stack' screen and move the image to cover the face.

Play the video and you'll see the blur moving in a line between the first keyframe (initial position) and the second keyframe (the one you added).

Repeat the procedure till you've covered all the video section where the face needs blurring - there is no movement too fast, unpredictable or unordered that you cant blur. And its really fast too once you get the hang of it. Its really great!

I hope this proves helpful for whoever needs to faceblur/blur any other moving section of a clip. If not just give me a shout and I'll try help.

Now all i need to figure out is how to blur multiple parts of a clip and then we're sorted.

Best,
Jack

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Thu, 10/21/2010 - 13:04
#12
Jack
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Re: Blurring faces

Video with Kdenlive blurred faces (bad language alert):
http://www.youtube.com/watch?v=dgKSNMMCat8

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