title: How to create a blank image with a specified size in Flutter
body: <p>I want to create a blank image with a white background and a specified size in Flutter, then I may add other images onto this blank image later to merge them as a new image.
  I am working on my first Flutter project and still learning new things by doing this project.
  Thanks for any hint.</p>
  
  <p>Update: The blank image here means an Image with only white color in it.</p>
  
  <p><a href="https://i.stack.imgur.com/4pSiG.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/4pSiG.png" alt="enter image description here"></a></p>