Question by busychild · Jun 21, 2012 at 06:52 PM · ios texture texture2d memory memory-leak

Loading external Image as Texture2D increases memory consumption dramatically on iOS

Hi folks,

i've a weird problem with loading external images as textures because the memory consumption increases unacceptable .

I'm currently loading about 100 images:

 IEnumerator loadTexture(string url, GameObject cube) {

     _textureURL = "file://" + Application.dataPath + "/../../Documents/webcontent/app/media/" + url; 
     _www = new WWW(_textureURL);
     yield return _www;
     _tempTexture = new Texture2D(256, 256);
     _www.LoadImageIntoTexture(_tempTexture);
     cube.renderer.material.mainTexture = _tempTexture;
 }

The whole images are using approximately 2-3MB of disc space but if i run the profiler i can see that these images are using more than 200MB of memory! What's going on there?

I also tried to initialize the Texture2D with different texture formats but this is not working as well just as loading the assets via the "System.IO.File.ReadAllBytes"-method and then load it on the texture (_tempTexture.LoadImage(textureBytes).

Thanks in advance for your help!

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whydoidoit · Jun 21, 2012 at 06:56 PM 0

Are your images power of 2 dimensions?

busychild · Jun 21, 2012 at 06:59 PM 0

No, but i've tried it with an image which is (loaded these image 100-times) - the result was the same but just in case i will give it one more try!

whydoidoit · Jun 21, 2012 at 07:02 PM 1

If they aren't power of two dimensions then it will get much bigger due to buffer allocations. Bear in mind images in memory are always massively bigger than jpg or png files as those are compressed file formats.

busychild · Jun 21, 2012 at 07:09 PM 0

Ok thanks! I've tried it but it turns out that a 512px x 512px .png image increases the memory much more than the other images. Here are the results from the profile:

Before loading the external images: http://www.equalion.de/help/before.jpg
After loading the external images: http://www.equalion.de/help/after.jpg

BTW: The .png image is using 101kb of disc space and i know that uncompressed images are getting bigger in memory than compressed ones but i can't believe that it increases from 10$$anonymous$$B disc space (100 * 101kb) to more than 400$$anonymous$$B in memory...

whydoidoit · Jun 21, 2012 at 08:40 PM 0

No the in memory size of your images is around 103$$anonymous$$B as a guess - one 512x512 image takes just over 1$$anonymous$$B of ram. The rest will be buffers etc used to import the image I imagine (it really is very costly). However, just because the OS profiler says you have that much memory does not mean that the application is using it - it can be allocated but not garbage collected yet.

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