Android Resize images according to the screen size of the device

I hope someone can help me. I have days looking for a way to Resize images in android according to the screen size of the device. Sometimes the picture is fine but when used in a slightly larger image comes to be very small and not resized or adapted to the screen size.

For there I saw that for every image that wanted to join the project, was to add image in different sizes, Example: 80x80, 160x160,220x220,320xx320 (each has the same name.) and that helped resized.

Or did so but not me. sometimes the image is totally distorted.

This is the code I use for ImageView

 <ImageView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/inicio"
            android:background="@drawable/inicio1"
            android:layout_centerHorizontal="true"
            android:layout_marginTop="40dp"
            android:layout_below="@+id/imageView"


            />

that I can do to make the image take an appropriate size according to the size of the screen.

Thank You