This exercise generate a blur bitmap by changing each pixel to the average of its surrounding 5x5 pixel.
Download the files.
Download and try the APK.
package com.example.androiddrawbitmap;
import java.io.FileNotFoundException;
import android.net.Uri;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
public class MainActivity extends Activity {
Button btnLoadImage;
ImageView imageResult, imageOriginal;
TextView textDur;
final int RQS_IMAGE1 = 1;
Uri source;
Bitmap bitmapMaster;
Canvas canvasMaster;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnLoadImage = (Button) findViewById(R.id.loadimage);
imageResult = (ImageView) findViewById(R.id.result);
imageOriginal = (ImageView)findViewById(R.id.original);
textDur = (TextView)findViewById(R.id.dur);
btnLoadImage.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
Intent intent = new Intent(
Intent.ACTION_PICK,
android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(intent, RQS_IMAGE1);
}
});
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode == RESULT_OK) {
switch (requestCode) {
case RQS_IMAGE1:
source = data.getData();
try {
bitmapMaster = BitmapFactory
.decodeStream(getContentResolver().openInputStream(
source));
imageOriginal.setImageBitmap(bitmapMaster);
loadBlurBitmap(bitmapMaster);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
break;
}
}
}
private void loadBlurBitmap(Bitmap src) {
if (src != null) {
Bitmap bmBlur;
long startTime = System.currentTimeMillis();
bmBlur = getBlurBitmap(src);
long duration = System.currentTimeMillis() - startTime;
imageResult.setImageBitmap(bmBlur);
textDur.setText("processing duration(ms): " + duration);
}
}
private Bitmap getBlurBitmap(Bitmap src) {
final int widthKernal = 5;
final int heightKernal = 5;
int w = src.getWidth();
int h = src.getHeight();
Bitmap blurBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
for (int x = 0; x < w; x++) {
for (int y = 0; y < h; y++) {
int r = 0;
int g = 0;
int b = 0;
int a = 0;
for (int xk = 0; xk < widthKernal; xk++) {
for (int yk = 0; yk < heightKernal; yk++) {
int px = x + xk -2;
int py = y + yk -2;
if(px < 0){
px = 0;
}else if(px >= w){
px = w-1;
}
if(py < 0){
py = 0;
}else if(py >= h){
py = h-1;
}
int intColor = src.getPixel(px, py);
r += Color.red(intColor);
g += Color.green(intColor);
b += Color.blue(intColor);
a += Color.alpha(intColor);
}
}
blurBitmap.setPixel(x, y, Color.argb(a/25, r/25, g/25, b/25));
}
}
return blurBitmap;
}
}
<LinearLayout 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/background_dark"
android:orientation="vertical"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:autoLink="web"
android:text="http://android-er.blogspot.com/"
android:textStyle="bold" />
<Button
android:id="@+id/loadimage"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Load Image 1" />
<ScrollView
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<ImageView
android:id="@+id/original"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:adjustViewBounds="true"
android:scaleType="fitXY" />
<ImageView
android:id="@+id/result"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:adjustViewBounds="true"
android:scaleType="fitXY" />
<TextView
android:id="@+id/dur"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
</LinearLayout>
</ScrollView>
</LinearLayout>
