my ($px, $py) = fitwarp2d($red_out_x, $red_out_y, $red_in_x, $red_in_y, 2);

my ($blue_new_x, $blue_new_y) = applywarp2d($px, $py, $blue_in_x, $blue_in_y);

#say for $blue_out_x, $blue_out_y, $blue_new_x, $blue_new_y, $blue_out_x - $blue_new_x, $blue_out_y - $blue_new_y;