MainActivity.kt

class PokemonDetectorActivity : BaseCameraActivity() {
  
    companion object {
        /** Dimensions of inputs.  */
        const val DIM_IMG_SIZE_X = 224
        const val DIM_IMG_SIZE_Y = 224
        const val DIM_BATCH_SIZE = 1
        const val DIM_PIXEL_SIZE = 3
        const val IMAGE_MEAN = 128
        private const val IMAGE_STD = 128.0f
    }

    private val intValues = IntArray(DIM_IMG_SIZE_X * DIM_IMG_SIZE_Y)
    private lateinit var imgData: ByteBuffer

    //...  
    private fun convertBitmapToByteBuffer(bitmap: Bitmap?) {
        //Clear the Bytebuffer for a new image
        imgData.rewind()
        bitmap?.getPixels(intValues, 0, bitmap.width, 0, 0, bitmap.width, bitmap.height)
        // Convert the image to floating point.
        var pixel = 0
        for (i in 0 until DIM_IMG_SIZE_X) {
            for (j in 0 until DIM_IMG_SIZE_Y) {
                val currPixel = intValues[pixel++]
                imgData.putFloat(((currPixel shr 16 and 0xFF) - IMAGE_MEAN) / IMAGE_STD)
                imgData.putFloat(((currPixel shr 8 and 0xFF) - IMAGE_MEAN) / IMAGE_STD)
                imgData.putFloat(((currPixel and 0xFF) - IMAGE_MEAN) / IMAGE_STD)
            }
        }
    }
  
    //...
}