Question Different output in Barracuda compared to Keras/ONNX

I have been struggling with my Keras2ONNX converted model for a few days. The output is different from what I get running the model from Keras and ONNXruntime. Maybe someone can spot my mistakes or tell me this is not yet supported.

The model classifies an image into 4 categories. Image input size is 180x180x3.

The same image(prescaled to 180x180) is loaded in both Keras/ONNXruntime and Unity.

Keras/ONNX predicts as expected:

********** KERAS predict *************
[ 2.179296 6.270509 -0.9740573 -3.7748256]
This image most likely belongs to ds-pass with a 98.28 percent confidence.
********* ONNX predict ***************
[ 2.1792946 6.2705064 -0.97405905 -3.774826 ]
This image most likely belongs to ds-pass with a 98.28 percent confidence.

But Barracuda predicts:

[ 6,128766 -0,5258042 -0,7985633 -1,13862 ]

I think the input values are correct in the 0-255 range, but I might be missing something.
The Unity code:

Code (CSharp):

1.  
2.  
3. void Classify(){
4.  
5.        var scaled = Resources.Load<Texture2D>("ds_pass_prescaled");
6.      
7.         Color32[] pix = scaled.GetPixels32();
8.         //Color[] pix = scaled.GetPixels();
9.         int ModelInputSize = 180;
10.         float[] floats = new float[ModelInputSize * ModelInputSize * 3];
11.      
12.  
13.         for (int i = 0; i < pix.Length; ++i)
14.         {
15.             var color = pix[i];
16.    
17.             //Values 0_255
18.             floats[i * 3 + 0] = color.r;
19.             floats[i * 3 + 1] = color.g;
20.             floats[i * 3 + 2] = color.b;
21.          
22.             //Values 0_1
23.             //floats[i * 3 + 0] = (color.r / 255f);
24.             //floats[i * 3 + 1] = (color.g / 255f);
25.             //floats[i * 3 + 2] = (color.b / 255f);
26.  
27.             //Values -1_1
28.             //floats[i * 3 + 0] = (color.r - 127) / 127.5f;
29.             //floats[i * 3 + 1] = (color.g - 127) / 127.5f;
30.             //floats[i * 3 + 2] = (color.b - 127) / 127.5f;
31.  
32.         }
33.  
34.         //Create the input tensor from pixel values
35.         Tensor in_tensor = new Tensor(1, ModelInputSize, ModelInputSize, 3, floats);
36.  
37.         worker.Execute(in_tensor);
38.  
39.         Tensor out_tensor = worker.PeekOutput("dense_1");
40.         var arr_comp = out_tensor.ToReadOnlyArray();
41.         Debug.Log(arr_comp);
42.  
43.  
44.         in_tensor.Dispose();
45.         out_tensor.Dispose();
46.         worker.Dispose();
47. }
48.  

The model:

The rescaling takes 0-255 into 0-1 range. I have also tried a version of the model without the rescaling layer with no luck.



I am running Unity 2020.3.2f1 and currently Barracuda 2.1.0 (Tested with 1.3.3 also)
Any kind of help is greatly appreciated.

 

Thank you for your answer.
I am currently using Barracuda 2.1.0 (Tested with 1.3.3 also). I will do some more testing on the channel order and come back.

 

Seems like I just needed to flip the input Texture2d vertically before feeding it to the Tensor.

Your idea of printing the pixel values ponted me in the right direction.

Thanks