How to convert a 2D ByteArray to bitmap?

[vincentme]

This should be a dumb question. Because I am a pure novince to android and kotlin, but now I need to create a demo to run a onnx model. It works on the desktop python api.

I followed onnxruntime-inference-examples-main/mobile/examples/super_resolution exactly. But the output of my model is a 2D ByteArray (unit8) image. So how to convert it to a bitmap for display?

This does not work, since the result of super_resolution was encoded, by mine is not.

val rawOutput = (output?.get(0)?.value) as ByteArray
val outputImageBitmap = byteArrayToBitmap(rawOutput)

private fun byteArrayToBitmap(data: ByteArray): Bitmap {
return BitmapFactory.decodeByteArray(data, 0, data.size)
}

now the error is java.lang.ClassCastException: byte[][] cannot be cast to byte[]

[Craigacp]

If you pull it out as a ByteBuffer then you might be able to feed it directly into Bitmap.copyPixelsFromBuffer assuming that the image is the right orientation and the channels are in the right place. This is an example of unpacking a FloatBuffer into a Java BufferedImage, but I'm not sure how to get from a BufferedImage into an Android Bitmap, and you'll also need to understand the orientation and channels behaviour of your output - https://github.com/oracle/sd4j/blob/main/src/main/java/com/oracle/labs/mlrg/sd4j/VAEDecoder.java#L119.