Crear un Dialogo Personalizado con Bordes redondeados

abajo_arriba_b.xml

<?xml version="1.0" encoding="utf-8"?>
<translate xmlns:android="http://schemas.android.com/apk/res/android"
    android:fromYDelta="-100%p"
    android:toYDelta="0%p"
    android:duration="500" />

arriba_abajo_b.xml

<?xml version="1.0" encoding="utf-8"?>
<translate xmlns:android="http://schemas.android.com/apk/res/android"
    android:fromYDelta="0%p"
    android:toYDelta="100%p"
    android:duration="500" />

corners.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">
    <solid android:color="#ffffff" />
    <corners
        android:bottomRightRadius="5dp"
        android:bottomLeftRadius="5dp"
        android:topLeftRadius="0dp"
        android:topRightRadius="0dp" />
    <stroke
        android:width="6dp"
        android:color="#ffffffff" />
</shape> 

Main.java

package test.cristian.suradialog;

import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;


public class Main extends ActionBarActivity {

    protected Button show;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        show = (Button) findViewById(R.id.show);
        show.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
               SuraDialog suraDialog = new SuraDialog(Main.this);
               suraDialog.show();
            }
        });
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

main.xml

<FrameLayout 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:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    tools:context=".Main">


    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Show Dialog"
        android:id="@+id/show"
        android:layout_gravity="center" />
</FrameLayout>

styles.xml

<resources>

    <!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <!-- Customize your theme here. -->
    </style>

    <style name="Dialog_Animation_UP_DOWN">
        <item name="android:windowEnterAnimation">@anim/abajo_arriba_b</item>
        <item name="android:windowExitAnimation">@anim/arriba_abajo_b</item>
    </style>

</resources>

sura_dialog.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    >

    <ImageView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/imgfondo"
        android:scaleType="centerCrop"
        android:adjustViewBounds="true"
        android:layout_gravity="center" />

    <LinearLayout
        android:orientation="vertical"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:background="@drawable/corners"
        android:layout_gravity="center_horizontal|bottom">

        <Button
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Mas Información"
            android:textColor="@android:color/white"
            android:id="@+id/btnmore"
            android:layout_gravity="center_horizontal|bottom" />
    </LinearLayout>

    <ImageButton
        style="?android:attr/buttonStyleSmall"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@android:color/transparent"
        android:id="@+id/imgcerrar"
        android:src="@android:drawable/ic_delete"
        android:layout_gravity="left|top"
        android:layout_marginBottom="5dp"/>
</FrameLayout>

SuraDialog.java

package test.cristian.suradialog;

import android.app.AlertDialog;
import android.content.Context;
import android.graphics.drawable.ColorDrawable;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.ImageButton;
import android.widget.ImageView;

import com.makeramen.roundedimageview.RoundedTransformationBuilder;
import com.squareup.picasso.Picasso;
import com.squareup.picasso.Transformation;

/**
 * Created by cristian on 8/07/15.
 */
public class SuraDialog extends AlertDialog {


    protected SuraDialog(Context context) {
        super(context);
        initDialog();
    }

    protected SuraDialog(Context context, int theme) {
        super(context, theme);
        initDialog();
    }

    protected SuraDialog(Context context, boolean cancelable, OnCancelListener cancelListener) {
        super(context, cancelable, cancelListener);
        initDialog();
    }

    private void initDialog() {
        LayoutInflater inflater = LayoutInflater.from(getContext());
        final View view = inflater.inflate(R.layout.sura_dialog, null);
        setView(view);

        ImageView imgfond = (ImageView) view.findViewById(R.id.imgfondo);

        Transformation transformation = new RoundedTransformationBuilder()
                .cornerRadiusDp(5)
                .oval(false)
                .build();

        Picasso.with(getContext()).
                load(R.drawable.fondo)
                .transform(transformation)
                .into(imgfond);

        ImageButton imgcerrar = (ImageButton) view.findViewById(R.id.imgcerrar);
        imgcerrar.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                SuraDialog.this.dismiss();
            }
        });

        getWindow().setWindowAnimations(R.style.Dialog_Animation_UP_DOWN);
        getWindow().setBackgroundDrawable(new ColorDrawable(android.R.color.transparent));
    }
}