Kdenlive/Manual/Clip Menu/Stabilize: Difference between revisions

Revision as of 08:50, 6 January 2013

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Stabilize

This menu item is available from right click on a clip in the project tree or under the project menu when a clip is selected in the project tree.

This feature applies image stabilization algorithms to the clip which can reduce the shakiness of a shaky bit of footage.

stabilize ( vstab)

This tutorial shows how to use the stabilize feature - vstab version:

The "shutter angle" setting that the narrator says he does not know what it does (1:35) ... Shutter angle is an angle that images could be maximum rotated for stabilization. see here.

stabilize (transcode)

Based on the tool tips from this screen and the doco here this what all the options mean:

optzoom = use optimal zoom (calculated from transforms) which means that 90% of transformations are hidden. default - checked.

accuracy = accuracy of shakiness detection. Should be >=shakiness factor. 1: low (fast processing) 15: high (slow processing) - default 4

algo (= algorithm used) unchecked =brute force. checked= small measurement fields - default = checked

maxangle = maximum angle to rotate - in radians. default = -1 which means no limit

realtive (typo ? in kdenlive) unchecked = absolute transform, checked = relative transform

zoom - additional zoom during transform default = 0

shakiness - how shaky is the video. and how quick is the camera? 1: little (fast processing) 10: very strong/quick (slow processing) Default = 4

invert - invert the transform. default = unchecked

sharpen - sharpen transformed image. amount of sharpening: 0: no sharpening. uses filter unsharp with 5x5 matrix Default = 0.8

stepsize - stepsize of search process, region around minimum is scanned with 1 pixel resolution- default = 6

show 0= draw nothing, 1 or 2 = show fields and transforms. Use 1 or 2 to preview what the process is going to do. default = 0

mincontrast below this contrast - the field is discarded. Range 0-1 default =0.3

smoothing = number of frames for lowpass filtering. Used to calculate number of frames to be used for lowpass filtering used for stabilizing. Number of frames = smoothing * 2 + 1. default =10. A larger smoothing means that we transform away more camera movements. The resulting clip has a lower change in camera speed. Demo of the difference here

maxshift maximal number of pixels to translate image. (default = -1 no limit)

crop unchecked = The border of the transformed frames contains the pixels from previous frames. Checked = black background. default = unchecked

This video shows a side by side comparison between vstab and transcode stabilize methods.

@@ Line 49: / Line 49: @@
 '''mincontrast''' below this contrast - the field is discarded.  Range 0-1 default =0.3
-'''smoothing''' = number of frames for lowpass filtering.  Used to calculate number of frames to be used for lowpass filtering  used for stabilizing. Number of frames = smoothing * 2 + 1  default =10. A larger smoothing means that we transform away more camera movements. The resulting clip has a lower change in camera speed. Demo of the difference  [http://public.hronopik.de/vid.stab/files/skiing_veryshaky_short_vs_longsmoothing_above.ogv here]
+'''smoothing''' = number of frames for lowpass filtering.  Used to calculate number of frames to be used for lowpass filtering  used for stabilizing. Number of frames = smoothing * 2 + 1.  default =10. A larger smoothing means that we transform away more camera movements. The resulting clip has a lower change in camera speed. Demo of the difference  [http://public.hronopik.de/vid.stab/files/skiing_veryshaky_short_vs_longsmoothing_above.ogv here]
 '''maxshift''' maximal number of pixels to translate image.    (default = -1 no limit)