Loading 8192x8192 textures at runtime on android

I'm using 8192x8192 truecolor textures in my android project and they work fine when used normally, but now I'm trying to switch to load them at runtime from the streaming assets folder using WWW.LoadImageIntoTexture. (note: I'm doing this because when they are not in the streamingAssets folder the bundle is very large; each 20mb image becomes 256mb).

This works fine when the build platform is standalone but when I switch it to android and run it in the editor I just get a blue texture rather than my image (similar result when running on a device except it's black).

A simplified project with just a 20 line script and an image (20mb) is here: https://drive.google.com/file/d/0ByNPa9Pa1jJ8YVZ1TDdISzFpb3c/view?usp=sharing

Full Script:

public class OptimizationTests : MonoBehaviour {

 WWW localFile;

 void Start()
 {
     string path = "file://" + Application.dataPath + "/StreamingAssets" + "/8kimage.jpg";
     StartCoroutine("LoadTexture", path);
 }

 public IEnumerator LoadTexture(string absoluteImagePath)
 {
     Texture2D texture = new Texture2D(4, 4, TextureFormat.RGBAFloat, false);

     localFile = new WWW(absoluteImagePath);
     yield return localFile;

     localFile.LoadImageIntoTexture(texture);
     GetComponent<Renderer>().material.mainTexture = texture;
 }

}