How can I read (from disk) and resize an image, in Flutter/Dart

Question

In Flutter/Dart, how can I perform the following 3 steps:

1. Read an image from disk,
2. Read its original dimensions (width and height),
3. Resiz

Answer 1

you can use the image class from dart ui library, get the image object with your desired width and height using the frameInfo from intantiateImageCodec and then save it in your desired path

 import 'dart:ui' as ui;

        Uint8List m = File(path).readAsBytesSync();
        ui.Image x = await decodeImageFromList(m);
        ByteData bytes = await x.toByteData();
        print('height is ${x.height}'); //height of original image
        print('width is ${x.width}'); //width of oroginal image

        print('array is $m');
        print('original image size is ${bytes.lengthInBytes}');

            ui.instantiateImageCodec(m, targetHeight: 800, targetWidth: 600)
            .then((codec) {
          codec.getNextFrame().then((frameInfo) async {
            ui.Image i = frameInfo.image;
            print('image width is ${i.width}');//height of resized image
            print('image height is ${i.height}');//width of resized image
            ByteData bytes = await i.toByteData();
            File(path).writeAsBytes(bytes.buffer.asUint32List());
            print('resized image size is ${bytes.lengthInBytes}');
          });
        });

Answer 2

You can use the Image widget in the Scaffold widget,

First of all you need to create assets folder in the root and add an images folder, after that add,

    flutter:
      assets:
        - assets/images/

to the pubspec.yaml file, after that

new Image(
          image: AssetImage('assets/images/pizzaFont.png'),
          height: 12,
          width:12, ......
   )

You can use width and height to change the size of the image.

For more information follow,

https://medium.com/@suragch/how-to-include-images-in-your-flutter-app-863889fc0b29