Flutter Image in Card Widget does not fill the whole card

I want to have a glass look background for my cards. When I pass the container in the card widget, the image is in the middle and too small.

Example:
Example of how it looks

My build method:

final width = MediaQuery.of(context).size.width;
final height = MediaQuery.of(context).size.height;
return Card(
  elevation: 6,
  color: backgroundColor,
  shape: RoundedRectangleBorder(
    borderRadius: BorderRadius.circular(14),
  ),
  child: InkWell(
    onTap: () {},
    child: Container(
      width: width / 1.6,
      height: height / 4,
      decoration: const BoxDecoration(
        image: DecorationImage(
          image: AssetImage('assets/images/card/test.png'),
          fit: BoxFit.fitWidth,
          alignment: Alignment.topCenter,
        ),
      ),
      child: Padding(
        padding: const EdgeInsets.only(left: 16.0, right: 16.0, top: 15, bottom: 0),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          mainAxisAlignment: MainAxisAlignment.spaceBetween,
          children: [
            Text(groupData.name, overflow: TextOverflow.ellipsis,),
            Text(groupData.moduleId, overflow: TextOverflow.ellipsis,), 
            Row(
              crossAxisAlignment: CrossAxisAlignment.center,
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: [
                Expanded(child: Text(moduleData.name, overflow: TextOverflow.ellipsis,)),
                Image.asset('assets/images/card/group_card_icon.png', height: 60, width: 60, fit: BoxFit.cover,)
              ],
            )
          ],
        ),
      ),
    ),
  ),
);