How to blur background on Android?

How to Blur Background on Android: A Step-by-Step Guide

Why Blur Background on Android?

In today’s digital age, taking and sharing high-quality images has become a habit. But, sometimes, we might want to blur the background of an image, especially when snapping selfies or group photos, to hide unnecessary distractions or individuals. Blurring the background can be a great way to maintain privacy, reduce distractions, or even create a professional look. So, how do we blur background on Android? Let’s dive in and find out!

BLE.Utils: A Simple and Effective Solution

One of the most popular and widely-used methods to blur background on Android is by using the BLE (Background Layover Effect) library. This library provides a straightforward way to implement background blurring, allowing you to focus on the main subject while hiding the surrounding distractions. Here’s a step-by-step guide on how to use BLE.utils:

Step 1: Add the BLE Library to Your Project

• Optional: If you’re building a new project, you can add the BLE library directly to your Android Studio project by clicking on File > New > New Module, selecting "Empty Activity", and then selecting "Download JAR archive" for the selected Gradle project.
• Alternative: If you prefer to use a pre-compiled JAR, download the BLE library from GitHub and add it to your project manually.

Step 2: Create a Blur Effect

After adding the library, you can create a blur effect by using the Bitmap class:

import android.graphics.Bitmap;



// Create a new Bitmap with the desired size

Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565);



// Apply blur effect to the bitmap

bitmap = applyBlur(bitmap);

Step 3: Apply the Blur Effect to the Desired Area

Once you have created a blurry background, you can apply the effect to the desired area. This is where things get interesting:

// Create a new Canvas and draw the blurred background

Canvas canvas = new Canvas(bitmap);

Paint paint = new Paint();

paint.setColor(Color.WHITE);

canvas.drawRect(0, 0, width, height, paint);

Other Methods and Libraries

While BLE.utils is a popular option, there are other methods and libraries that can help you achieve similar results. Here are a few:

• Paint: You can use the Paint class to manually create a blur effect by drawing a transparent layer over the original image:

  Paint paint = new Paint();
  
  paint.setMaskFilter(new BlurMaskFilter(5, BlurMaskFilter.Blur.NORMAL));
  
  paint.setColor(Color.TRANSPARENT);
  
  canvas.drawPath(path, paint);

• GLSurfaceView: If you’re building a game or targeting Android TV, you can use the GLSurfaceView to create a custom filter for blurring the background:

  public class BlurFragment extends GLSurfaceView {
  
  private final int blurRadius = 20;
  
  
  
  // ...
  
  
  
  public void onDrawFrame(GL10 gl) {
  
      gl.glColorMask(0, 0, 0, 0);
  
      gl.glClearColor(1, 1, 1, 1);
  
      gl.glClear(GL_COLOR_BUFFER_BIT);
  
      gl.glEnable(GL_BLEND);
  
      gl.glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
  
      // Apply blur effect
  
      gl.glPushMatrix();
  
      gl.glTranslatef(0, 0, -5);
  
      gl.glScalef(1, 1, 1);
  
      gl.glTranslatef(0, 0, -5);
  
      gl.glEnd();
  
      gl.glPopMatrix();
  
  }
  
  }

Additional Tips and Tricks

• When using BLE.utils, make sure to set the MinMax property correctly to achieve the desired blur effect:

  BLEPreferences.putInt("BLUR_LEVEL", 10);
  
  BLEPreferences.putBoolean("BLUR_OVEREXPOSED", true);

• Be mindful of the memory usage and performance impact when applying a blur effect to a large image:

  // Use in-sample processing to reduce memory usage
  
  int inputWidth = 4000; // width of the original image
  
  int inputHeight = 3000; // height of the original image
  
  int blurRadius = 5; // Set the blur radius
  
  int outputWidth = 2000; // desired width
  
  int outputHeight = 1500; // desired height

Conclusion

Blurring the background on Android is a simple and effective way to hide distractions or maintain privacy. With the BLE.utils library and some code tweaks, you can create a professional-looking effect for your images. Remember to consider memory usage and performance when applying a blur effect, especially for large images. Experiment with different libraries and methods to achieve the desired blur level and reduce distractions in your Android app.

References:

• BLE.utils GitHub Repository: https://github.com/oleshKO/blurred-library/
• Android OpenGL Documentation: https://developer.android.com/intl/ko/kotlin/android/guide/topics/graphics.opengl.html
• Android Paint Documentation: https://developer.android.com/reference/android/graphics/Paint.html

Additional Resources:

• A comprehensive guide on Android graphics and performance optimization: https://www.guardsquare.net/en/blog/2018/02/19/comprehensive-guide-on-android-graphics-and-performance-optimization/
• A tutorial on creating a blur effect using OpenGL: <https://www.gametutorials.com/tutorial-canvas-blur-effect/)
• Android Architecture Components and Best Practices: https://www.guardsquare.net/en/blog/2018/02/19/why-architecture-components-and-best-practices/

I hope this article has helped you blur background on Android and unlock new creative possibilities for your app or project!