Flutter User ColorFiltered to dark image with matrix

Question

I want in flutter to user ColorFiltered, so i can make jpg image dark here is my code but i didn't get the right result, i don't understand matrix and how to change color this code was from internet, please any idea will be welcome.

ColorFiltered(
              child: ColorFiltered(
                child: Image.asset(
                  'myimage.jpg',
                  fit: BoxFit.fill,
                ),
                colorFilter: ColorFilter.matrix(
                  [
                    //R  G   B    A  Const
                    -1, 0, 0, 0, 190, //
                    0, -1, 0, 0, 255, //
                    0, 0, -1, 0, 255, //
                    0, 0, 0, 1, 0, //
                  ],
                ),
              ),
              colorFilter: ColorFilter.mode(
                Colors.white,
                BlendMode.darken,
              ),
            )

Answer 1

If you just want to make your image darker the better solution is probably just putting a transparent black Container over your image with a Stack widget:

Stack(children: <Widget>[
  Image.network('https://picsum.photos/250?image=9'),
  Positioned.fill(
    child: Opacity(
      opacity: 0.5,
      child: Container(
        color: const Color(0xFF000000),
      ),
    ),
  ),
]),

If you really want to use ColorFiltered let me know but you can do something like this:

ColorFiltered(
  child: Image.network('https://picsum.photos/250?image=9'),
  colorFilter: const ColorFilter.mode(
    Color(0xFF3D3D3D),
    BlendMode.darken,
  ),
),

Keep in mind that ColorFiltered will not just add a new grey layer over the image. It transforms every pixel of the image separately. As per the documentation:

This widget applies a function independently to each pixel of child's content, according to the ColorFilter specified.