Using image as background Header Bar and footer shows white paddings - android-layout

Question

I want to style the action bar and footer using the background image of header and footer respectively. When it comes to the execution by modifying the layout, it seems there are white spaces which is not pleasant for the appearance. All of my images uses png files with transparent background. Are there any methods for modifying the transparency of the header and footer background ? The below os my relative layout structure :
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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:background="#android:color/transparent" >
<!-- Header aligned to top -->
<RelativeLayout
android:id="#+id/header"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:background="#drawable/heading"
android:gravity="center" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="5dp"
android:text="Fixed Header"
android:textColor="#000"
android:textSize="20sp" />
</RelativeLayout>
<!-- Footer aligned to bottom -->
<RelativeLayout
android:id="#+id/footer"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:background="#drawable/footer"
android:gravity="center" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="5dp"
android:text="Fixed Footer"
android:textColor="#000"
android:textSize="20sp" />
</RelativeLayout>
<!-- Scrollable Item below header and above footer -->
<ScrollView
android:id="#+id/scrollableContents"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_above="#id/footer"
android:layout_below="#id/header"
android:background="#ff5" >
<!-- Inflate the contents of the ScrollView dynamicaly -->
</ScrollView>
</RelativeLayout>

Answer 1

The white part of your header & footer comes from activity background (because listview is below header and above footer) which could be changed by using styles :
Define custom color in res/values/colors.xml
<color name="custom_theme_color">#b0b0ff</color>
Create a style in res/values/styles.xml
<style name="CustomTheme" parent="android:Theme.Light">
<item name="android:windowBackground">#color/custom_theme_color</item>
<item name="android:colorBackground">#color/custom_theme_color</item>
</style>
(windowBackground can be a drawable reference too)
Set this style to your activity in Manifest.xml :
<activity
android:name="myActivity"
android:theme="#style/CustomTheme">
For more details see Android Styles and Themes