Kdenlive/Руководство/меню Проект/Стабилизация

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Стабилизация

Этот пункт меню доступен из контекстного меню клипа, находящегося в дереве проекта или в меню Проект, когда клип выделен в дереве проекта.

Эта функция применяет для клипа, алгоритм стабилизации изображения, который может уменьшить дрожание кадра, обусловленное нестабильным положением камеры (например съёмка с рук и т.п.)

Есть два различных метода стабилизации доступных в 'Kdenlive' - vstab и transcode (перекодировать).

Это видео показывает, рядом сравнение методов стабилизации vstab и transcode .


стабилизация ( vstab)

Основано на этой работе.

В этом учебнике показано, как использовать функцию стабилизации - vstab версии:

Настройки "shutter angle" - расказчик говорит что не знает что это такое (1:35) ... Shutter angle - это угол съёмки - максимальный угол на который может быть повернуто изображение, подлежащее стабилизации. См. здесь.

стабилизация (transcode)

На основании этих советов и документов здесь значение всех опций:

optzoom = use optimal zoom (calculated from transforms). Causes video to zoom until 90% of transformations are hidden. default - checked. Hint: You can further zoom in with the zoom option

accuracy = accuracy of shakiness detection. Should be >=shakiness factor. 1: low (fast processing) 15: high (slow processing) - default 4. Recommended 8

algo (= algorithm used) checked= small measurement fields - default = checked. Unchecked means use brute force algorithm. The brute force algorithm is deprecated.

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

relative unchecked = absolute transform (don't use this), checked = relative transform. Default is checked.

zoom - Additional zoom during transform. Percentage to zoom > 0 = zoom in, <0 = zoom out. The zoom specified here is additional to the optimum zoom calculated by the program when optzoom is checked. 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. Note: large values may also reduce the accuracy. This is due to the internals of the movement-detection. Typically you don't need a value greater than 7.

invert - invert the transform. default = unchecked. Inverting the transform is pointless - leave unchecked.

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

stepsize - step size 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. example default = 0. Non-zero values of this parameter are not relevant in the Kdenlive implementation - use zero.

mincontrast below this contrast - the field is discarded. Range 0-1 default =0.3. You may want to used a smaller value for a really low contrast clip.

smoothing Controls the amount of smoothing/stabilization. The larger the value for smoothing the more camera movements are compensated. The resulting clip has a lower change in camera speed.

Technically it is the number of frames for lowpass filtering = smoothing * 2 + 1.

Eg with a with 25 fps clip, a value of 12 for the smoothing factor means we would smooth over one second - 12 frames behind the current frame + the current frame (1) + 12 frames after the current frame. default =10

Demo of the difference here (top:3, bottom: 30)

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

Пример работы эффекта стабилизации - transcode с оригиналом автора - Georg Martius

Рядом

Тряска устранена

Оригинальный