Color-Thief Node plugin error: "Image given has not completed loading"

Working in Node/Express, I was trying to get the npm package color-thief to grab the dominant color from an image, and it failed because "image given has not completed loading".

The image was, again, local, so it shouldn't have had this particular problem. And besides that, color-thief returns a promise, and I was using async/await, so it should have waited however long it took for the image to load instead of throwing an error.

Below is my SSCCE code:

const ColorThief = require('color-thief');

let colorThief = new ColorThief();

async function getDominantColor() {
    const img = 'public/img/seed/big-waves-2193828__340.webp';
    const dominantColor = await colorThief.getColor(img);
    console.log(dominantColor);
}

getDominantColor();