snap method
Implementation
List<Color> snap(int w, int h) {
List<Color> f = List.generate(w * h, (_) => Colors.transparent);
for (int x = 0; x < w; x++) {
for (int y = 0; y < h; y++) {
f[y * w + x] = getColorAtPixel(
(x * (image.width - 1) / (w - 1)).floor(),
(y * (image.height - 1) / (h - 1)).floor());
}
}
return f;
}