AndroidMainActivityLayoutButtonTextImage.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.example.dell.opencvandroid.MainActivity">

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Display Toast Message"
        android:onClick="displayToast"
        />

    <ImageView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:src="@drawable/test"
        android:id="@+id/img"
        android:adjustViewBounds="true"
        />

</LinearLayout>