adds organic noise to AI generated images

genAI_noise.sh

# adds organic noise to AI generated images
# requires ImageMagick `convert` command
function makenoise {
    # Get the input extension and use the same one for output
    imageName="$1"
    basename=$(basename "$imageName")
    extension="${imageName##*.}"

    # Split the image into channels
    convert "$imageName" -separate "channel_%d.png"

    # Add noise to each channel
    noiseLevel=0.4
    convert "channel_0.png" -evaluate gaussian-noise "$noiseLevel" "channelnoise_0.png"
    convert "channel_1.png" -evaluate gaussian-noise "$noiseLevel" "channelnoise_1.png"
    convert "channel_2.png" -evaluate gaussian-noise "$noiseLevel" "channelnoise_2.png"

    # Combine the noisy channels with the original extension
    convert "channelnoise_0.png" "channelnoise_1.png" "channelnoise_2.png" -combine "${basename}-noise.${extension}"

    # Catch errors and delete temp files
    if [[ $? -ne 0 ]]; then
        echo "Error adding noise to image"
        rm channel_*.png
        rm channelnoise_*.png
        exit 1
    fi
    rm channel_*.png
    rm channelnoise_*.png
    echo "Created ${basename}-noise.${extension}"
}