Generate white-balanced & cropped final images from SR2023 Virtual Competition recordings

gather-images.sh

#!/bin/sh

set -euo pipefail

# Requirements:
# - ImageMagick and FFMPEG (cli tools on PATH)
# - The script from http://www.fmwconcepts.com/imagemagick/whitebalance/index.php, +x and on PATH
#
# Usage:
# - cd into the directory containing the recordings
# - run this script

# We only have 20 matches
for matchno in $(seq 0 19)
do
    # Extract the last frame from the video
    ffmpeg -sseof -3 -i match-${matchno}.mp4 -update 1 -q:v 1 -y last-${matchno}.raw.jpg

    # Balance the image using a pixel known to be in the background
    whitebalance 1,1 last-${matchno}.raw.jpg last-${matchno}.balanced.jpg

    # Crop to the arena; size and offset manually determined by experimentation
    convert last-${matchno}.balanced.jpg -crop 1152x882+380+95 last-${matchno}.cropped.jpg
done