Clickable invisible checkboxes

I am trying to cover a png image in checkboxes and make them invisible, so that when the app is run, any part of the image can be selected. Just for trying it, I put in 3 checkboxes, but the moment I make them transparent and run the app, they are not clickable anymore. How do I make the boxes invisble/opaque and clickable?

Here is a snippet of my XML code.

<CheckBox
    android:visibility="visible"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/checkBox29"
    android:checked="false"
    android:layout_toRightOf="@+id/checkBox30"
    android:layout_below="@+id/rarm"
    android:layout_alignBottom="@+id/rarmtypeinfo"
    android:layout_alignRight="@+id/injury"
    android:layout_alignEnd="@+id/injury"
    android:clickable="false"
     />


<CheckBox
    android:visibility="visible"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/checkBox30"
    android:checked="false"
    android:layout_below="@+id/rarmtypeinfo"
    android:layout_toRightOf="@+id/male"
    android:layout_toEndOf="@+id/male"
    android:layout_marginTop="8dp"

    android:clickable="true" />

<CheckBox
    android:visibility="visible"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/checkBox31"
    android:checked="false"
    android:cursorVisible="false"
    android:contextClickable="false"
    android:layout_alignBottom="@+id/checkBox30"
    android:layout_toRightOf="@+id/checkBox29"
    android:layout_toEndOf="@+id/checkBox29"
    android:clickable="false"
     />

</RelativeLayout>