FrameBlend

The FrameBlend node interpolates frames by generating an additive composite of the frames that precede and follow it, rather than creating mere copies between the existing frames. This method creates “ghosting” around all fast moving features. The results may look odd when viewed as part of a still frame, but will contribute to smoother motion during actual playback.

You should insert this node before the temporal effect you want to influence (for example, before a Retime node).

Inputs and Controls

Connection Type

Connection Name

Function

Input

unnamed

The image sequence to blend.

mask

An optional image to use as a mask. By default, the frame blend is limited to the non-black areas of the mask.

At first, the mask input appears as triangle on the right side of the node, but when you drag it, it turns into an arrow labeled mask. If you cannot see the mask input, ensure that the mask control is disabled or set to none.

Control (UI)

Knob (Scripting)

Default Value

Function

FrameBlend Tab

channels

channels

all

The frame blend is only applied to these channels.

If you set this to something other than all or none, you can use the checkboxes on the right to select individual channels.

Number of frames

numframes

5

Sets the number of frames to blend together to create the effect:

When Custom is disabled, blend together Number of frames-1 previous frames and the current frame, creating a trail-like effect on moving objects.

When Custom is enabled, then the Number of frames are evenly distributed across the specified range.

Frame Range

startframe

-1

When Custom is enabled, the specified frame range is blended together producing the same result for every output frame (unless you put an expression into the frame numbers).

endframe

-1

Custom

userange

disabled

When enabled, use the Frame Range controls to specify the blended frame range.

Input Range

getinputrange

N/A

Click to automatically use the input sequence frames as the blend FrameRange.

Foreground matte

N/A

disabled

Enables the associated matte channel to the right. Disabling this checkbox is the same as setting the channel to none.

inputmask

none

Use this channel as a matte around a moving foreground object so that only pixels with a value of zero are blended. If you blend enough frames together and the object moves enough, the object is removed from the output to produce a clean background plate.

output Image count to

N/A

disabled

Enables the associated mask channel to the right. Disabling this checkbox is the same as setting the channel to none.

blendmask

none

When enabled, saves a floating point alpha image to a channel you specify; the result indicates the number of images that contributed to each pixel of the matte.

To normalize the alpha, divide the number 1 by the number of frames averaged, and then multiply the alpha channel by this result. You can also use the inverse of this matte for additional degraining.

mask

N/A

disabled

Enables the associated mask channel to the right. Disabling this checkbox is the same as setting the channel to none.

maskChannelInput

none

The channel to use as a mask. By default, the blend is limited to the non-black areas of this channel.

inject

inject

disabled

Copies the mask input to the predefined mask.a channel. Injecting the mask allows you to use the same mask further downstream.

invert

invert_mask

disabled

Inverts the use of the mask channel so that the blend is limited to the non-white areas of the mask.

fringe

fringe

disabled

When enabled, only apply the effect to the edge of the mask.

When disabled, the effect is applied to the entire mask.

mix

mix

1

Mixes between the original image at 0 and the full frame blend at 1.

Step-by-Step Guides

Interpolation