How to add an image to the Tab button ANDROID

I want to set an image instead of text in my tabs, i tried to add an "background" but it didnt work. it setted an backgroud to all of my tabs or to the layout. This is my main xml layout with tabs:

<TabHost
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:id="@+id/tabHost"
    android:layout_alignParentTop="true"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true">
    <ScrollView
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:fillViewport="false">
        <LinearLayout
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:orientation="vertical">

            <TabWidget
                android:id="@android:id/tabs"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:onClick="clickOnList"
                />
            <FrameLayout
                android:id="@android:id/tabcontent"
                android:layout_width="fill_parent"
                android:layout_height="fill_parent">

                <RelativeLayout
                    android:orientation="vertical"
                    android:layout_width="fill_parent"
                    android:layout_height="460dp"
                    android:id="@+id/Home"
                    android:weightSum="1">

                    <Button
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:text="Scan"
                        android:id="@+id/scanButton"
                        android:layout_gravity="center_horizontal"
                        android:layout_alignParentTop="true"
                        android:layout_centerHorizontal="true"
                        android:layout_marginTop="10dp" />

                    <TextView
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:text="Scan to find threats"
                        android:id="@+id/listViewTitle"
                        android:textStyle="bold"
                        android:textSize="18dp"
                        android:visibility="visible"
                        android:layout_gravity="center_horizontal"
                        android:layout_below="@+id/scanButton"
                        android:layout_centerHorizontal="true"
                        android:layout_marginTop="10dp" />

                    <ListView
                        android:layout_width="wrap_content"
                        android:layout_height="240dp"
                        android:id="@+id/suspectsList"
                        android:layout_below="@+id/listViewTitle"
                        android:layout_alignParentLeft="true"
                        android:layout_alignParentStart="true"
                        android:layout_marginTop="10dp" />

                    <Button
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:text="Click to Connect"
                        android:id="@+id/Connect_Button"
                        android:layout_gravity="center_horizontal"
                        android:onClick="loginFunc"
                        android:layout_below="@+id/Apply"
                        android:layout_centerHorizontal="true"
                        android:layout_marginTop="10dp" />

                    <Button
                        style="?android:attr/buttonStyleSmall"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:text="Apply All"
                        android:id="@+id/Apply"
                        android:layout_gravity="center_horizontal"
                        android:layout_below="@+id/suspectsList"
                        android:layout_centerHorizontal="true"
                        android:layout_marginTop="10dp" />

                    <Button
                        style="?android:attr/buttonStyleSmall"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:text="r"
                        android:id="@+id/restart"
                        android:layout_gravity="right"
                        android:layout_toRightOf="@+id/scanButton"
                        android:layout_marginTop="10dp"
                        android:layout_marginLeft="50dp">
                        </Button>

                </RelativeLayout>

                <LinearLayout
                    android:id="@+id/Quarantined"
                    android:layout_width="fill_parent"
                    android:layout_height="460dp"
                    android:orientation="vertical"
                    android:layout_gravity="right|bottom"
                    android:onClick="clickOnList">

                    <TextView
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:text="Quarantined:"
                        android:id="@+id/QuarantinedListTitle"
                        android:textStyle="bold"
                        android:textSize="18dp"
                        android:visibility="visible"
                        android:layout_gravity="center_horizontal"
                        android:layout_below="@+id/scanButton"
                        android:layout_centerHorizontal="true"
                        android:layout_marginTop="10dp" />

                    <ListView
                        android:layout_width="wrap_content"
                        android:layout_height="240dp"
                        android:id="@+id/QuarantinedListView"
                        android:layout_margin="10dp" />

                    <Button
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:text="Unquarantine Selected"
                        android:id="@+id/unQuarantinedSelected"
                        android:layout_alignBottom="@+id/tabHost"
                        android:layout_centerHorizontal="true"
                        android:layout_marginLeft="75dp" />
                </LinearLayout>

                <RelativeLayout
                    android:id="@+id/History"
                    android:layout_width="fill_parent"
                    android:layout_height="460dp"
                    android:orientation="vertical"
                    android:layout_gravity="center_horizontal|bottom">

                    <TextView
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:textAppearance="?android:attr/textAppearanceLarge"
                        android:text="History:"
                        android:id="@+id/historyTitle"
                        android:layout_alignParentTop="true"
                        android:layout_centerHorizontal="true" />

                    <ListView
                        android:layout_width="wrap_content"
                        android:layout_height="fill_parent"
                        android:id="@+id/HistoryListView"
                        android:layout_centerHorizontal="true"
                        android:layout_below="@+id/historyTitle"
                        android:layout_margin="10dp" />
                </RelativeLayout>

            </FrameLayout>

        </LinearLayout>
    </ScrollView>
</TabHost>

and this is how it looks like: http://ift.tt/1IPeb38

This is how i initialized the tabs:

TabHost tabHost = (TabHost)findViewById(R.id.tabHost);
// Create Tabs
tabHost.setup();
//1st tab - HomeTab
TabHost.TabSpec tabSpec = tabHost.newTabSpec("home");
//        tabHost.getTabWidget().setBackgroundResource(R.drawable.mglogo);
tabSpec.setContent(R.id.Home);
tabSpec.setIndicator("Home");
tabHost.addTab(tabSpec);
//2nd tab - HistoryTab
tabSpec = tabHost.newTabSpec("quarantine list");
tabSpec.setContent(R.id.Quarantined);
tabSpec.setIndicator("Quarantine List");
tabHost.addTab(tabSpec);
//3rd tab - HistoryTab
tabSpec = tabHost.newTabSpec("history");
tabSpec.setContent(R.id.History);
tabSpec.setIndicator("History");
tabHost.addTab(tabSpec);

i want to change the text : HOME / QUARANTINED / HISTORY to icons.

thanks in advanced!