overlap method
Do merge image. Overlaying the images
Implementation
Future<Image> overlap(Image other) {
PictureRecorder recorder = PictureRecorder();
final paint = Paint();
Canvas canvas = Canvas(recorder);
final totalWidth = max(width, other.width);
final totalHeight = max(height, other.height);
canvas.drawImage(this, Offset.zero, paint);
canvas.drawImage(other, Offset.zero, paint);
return recorder.endRecording().toImage(totalWidth, totalHeight);
}