greyscale constant
A matrix that turns the image into greyscale.
Implementation
static const List<double> greyscale = <double>[
0.2126,
0.7152,
0.0722,
0,
0,
0.2126,
0.7152,
0.0722,
0,
0,
0.2126,
0.7152,
0.0722,
0,
0,
0,
0,
0,
1,
0,
];