Plain call vs method call
In most cases there are two ways of calling API functions: as a function and as a class method.
//import for function call
import { flip } from 'image-js';
// Method call on the image instance
const flipped1 = image.flip(options);
// Equivalent plain method call
const flipped2 = flip(image, options);
There is no particular advantage using one way over another, you are free to use whichever suites your needs best.