Texture2d.LoadImage too slow for use (iOS)

Questions & Answers
1

I am working on a project which downloads png files from a web server and loads them into a Texture2D for use.

The following code highlights a very severe problem with the Teture2D LoadImage method. Namely, it takes 250ms to load a 500x500 pixel texture.

DateTime nowTime = DateTime.Now;
string completedPath = "A local path"
byte [] textureData = File.ReadAllBytes(completedPath);
Debug.Log ("Loading  bytes " + (DateTime.Now - nowTime).TotalMilliseconds + "ms");

nowTime = DateTime.Now;
Texture2D tex = new Texture2D(0,0);
tex.LoadImage(textureData);
Debug.Log ("Loading texture  " + (DateTime.Now - nowTime).TotalMilliseconds + "ms");

The output from this code is as follows (When run on an iPhone 4):

Loading  bytes 10.187ms
Loading texture  235.297ms

Is there a faster way to load a png from disk? This seems like a ridiculous amount of time to take to load a simple image.
If possible I would like to avoid the use of Asset Bundles.

As a comparison. Loading the same texture on the same device (iPhone 4) using pure objective C takes 10 ms.

    float timeNow = CACurrentMediaTime();
    UIImage *image = [UIImage imageNamed:@"brand1365761681365.png"];
    NSLog(@"Time taken on ios %f ms", (CACurrentMediaTime() - timeNow)*1000.f);

Time taken on ios 10.370380ms

Loading the texture using the WWW class takes even longer, around 1000ms.

2

Using LoadImage on a Texture2D on the device is a lot slower than it is in the editor and as @OwenW and I found out through experiments in the comments to the question, WWW is an order of magnitude faster.

Use:

    var www = new WWW("file://" + path);
    var texture = www.textureNonReadable;

Rather than creating a Texture2D and using LoadImage when working on iOS.