In animation production, inbetweening creates intermediate frames between two keyframes, so that the audience can see the smooth movement between the two frames. Frame interpolation is filling in-betweens by morphing one image into another with AI software. Note that the changes between the two frames are subtle and predictable. This tutorial is a step-by-step guide on how to use Frame interpolation from Google research GitHub.
1. Create a “interpolation” directory on your local drive. Open a dos prompt, navigate to this directory. Download the code from frame-interpolation GitHub repository by the command:
>git clone https://github.com/google-research/frame-interpolation.git
A new directory “frame-interpolation” is created under “interpolation.”
2. Under “interpolation” directory, create another directory called “pretrained_models.” Go to Google Drive to download “film_net” and “vgg.” Put them under “pretrained_models” directory.
3. You need to configure a virtual environment to run the code. If you haven’t installed Anaconda3, go to install Anaconda3.
4. Setup a conda environment with the instruction.
5. Prepare two images for the start and the end frames. Rename files to “one.png” and “two.png.” Put them under “frame-interpolation\photos” directory.
6. Open an Anaconda Prompt. Run command:
>conda activate tf_env_new
7. Still in the Anaconda prompt, go to the directory “interpolation” and run command:
>python -m frame-interpolation.eval.interpolator_cli --pattern “frame-interpolation/photos” --model_path pretrained_models/film_net/Style/saved_model --times_to_interpolate 6 --output_video
8. When it finishes, the image sequence and a new video mp4 file are saved at “frame-interpolation\photos” directory.
9. If you cannot play the mp4 file due to encoding differences, import the image sequence to After Effects or other video editing tools to render as a video.
