Problema com java.lang.NullPointerException android.graphics.Bitmap.compress

Olá estou tendo esse erro em meu código alguém poderia me ajudar a resolver isso?

grato desde já.

java.lang.NullPointerException: Attempt to invoke virtual method 'boolean android.graphics.Bitmap.compress(android.graphics.Bitmap$CompressFormat, int, java.io.OutputStream)' on a null object reference
            at map.app.fragments.ReportFragment.putImgToBytearray(ReportFragment.kt:177)

Linha do erro

bitmap.compress(Bitmap.CompressFormat.JPEG, 70, stream)

código

private fun putImgToBytearray(): ByteArray {
        val stream = ByteArrayOutputStream()
        val drawable = this.imgThumb!!.drawable as BitmapDrawable
        val bitmap = drawable.bitmap
        bitmap.compress(Bitmap.CompressFormat.JPEG, 70, stream)

        return stream.toByteArray()
    }

	código onActivityResult 

	 

    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
        super.onActivityResult(requestCode, resultCode, data)
        if (requestCode == IMAGE_PICK_CODE && resultCode == RESULT_OK) {
    
    
            try {
    
                //Getting the Bitmap from Gallery
                val bitmap = MediaStore.Images.Media.getBitmap(context.contentResolver, this.imageUri) as Bitmap?
                this.imgThumb!!.setImageBitmap(bitmap)
                this.pictureTaken = true
            } catch (e:IOException) {
                e.printStackTrace()
            }
        } else {
            Toast.makeText(context, "Error loading image", Toast.LENGTH_LONG)
        }
    }

	método para abrir a galeria e pegar uma imagem,sim é uma adaptação 

	   

    fun openCamera() {
        try {
            val imageFile = createImageFile()
            val callCameraIntent =  Intent(Intent.ACTION_PICK, MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
            if(callCameraIntent.resolveActivity(activity.packageManager) != null) {
                val authorities = activity.packageName + ".fileprovider"
                this.imageUri = FileProvider.getUriForFile(context, authorities, imageFile)
                callCameraIntent.putExtra(MediaStore.EXTRA_OUTPUT, imageUri)
                startActivityForResult(callCameraIntent, IMAGE_PICK_CODE)
            }
        } catch (e: IOException) {
            Toast.makeText(context, "Could not create file!", Toast.LENGTH_SHORT).show()
        }
    }