I'm currently using https://www.npmjs.com/package/pixfinder to try and detect holes in my paper targets to automatically score my target. I placed it against a red backer board, took a picture of it and I was trying to find the "red" in the image.

Component code.

import * as pix from 'pixfinder';

@Component({
  selector: 'app-find-bullets',
  templateUrl: './find-bullets.component.html',
  styleUrls: ['./find-bullets.component.scss']
})
export class FindBulletsComponent implements AfterViewInit {

  bulletCount: number = 0;
  @ViewChild('img') img!: ElementRef<HTMLImageElement>;

  constructor() { }

  ngAfterViewInit(): void {
    var holes = pix.findAll({
      img: this.img.nativeElement,
      distance: 2,
      colors: ['#6e0917'], //red
      clearNoise: 10,
    });
    console.log(holes)
    this.bulletCount = holes.length;
  }
}

bulletCount is always "1", with the points being essentially the whole target if I'm reading this right: