你可以试试这个：

XFile? imageFile = await ImagePicker().pickImage(source: ImageSource.camera);
if (imageFile != null) {
  final decodedImage = await decodeImageFromList(await imageFile.readAsBytes());
final height = decodedImage.height;  // Image height
final width = decodedImage.width;  // Image width
}

使用下面的代码，您可以获得Image的不同内容

import 'dart:io';

XFile? image = await ImagePicker().pickImage(source: ImageSource.gallery);
var decodedImage = await decodeImageFromList(image.readAsBytesSync());
print(decodedImage.width);
print(decodedImage.height);