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Android, How to crop circular area from bitmap
This example demonstrates how to crop circular area from bitmap in Android .
Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.
Step 2 − Add the following code to res/layout/activity_main.xml.
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity" android:id="@+id/rl" android:padding="16dp" android:background="#edf2ea"> <ImageView android:id="@+id/iv" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerInParent="true"/> <Button android:id="@+id/btn" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Circular It" android:layout_alignParentBottom="true" android:layout_alignParentRight="true"/> </RelativeLayout>
Step 3 − Add the following code to src/MainActivity.java
package com.medkart.sample;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.RectF;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.RelativeLayout;
public class MainActivity extends AppCompatActivity {
private Context mContext;
private Resources mResources;
private RelativeLayout mRelativeLayout;
private Button mBTN;
private ImageView mImageView;
private Bitmap mBitmap;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Get the application context
mContext = getApplicationContext();
// Get the Resources
mResources = getResources();
// Get the widgets reference from XML layout
mRelativeLayout = (RelativeLayout) findViewById(R.id.rl);
mImageView = (ImageView) findViewById(R.id.iv);
mBTN = (Button) findViewById(R.id.btn);
// Get the bitmap resource id
final int bitmapResourceID =R.drawable.flower;
// Set an image to ImageView
mImageView.setImageBitmap(BitmapFactory.decodeResource(mResources, bitmapResourceID));
// Set a click listener for Button widget
mBTN.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
// Get the bitmap from drawable resources
mBitmap = BitmapFactory.decodeResource(mResources, bitmapResourceID);
// Create a circular bitmap
mBitmap = getCircularBitmap(mBitmap);
// Add a border around circular bitmap
mBitmap = addBorderToCircularBitmap(mBitmap, 15, Color.WHITE);
// Add a shadow around circular bitmap
mBitmap = addShadowToCircularBitmap(mBitmap, 4, Color.LTGRAY);
// Set the ImageView image as drawable object
mImageView.setImageBitmap(mBitmap);
}
});
}
protected Bitmap getCircularBitmap(Bitmap srcBitmap) {
// Calculate the circular bitmap width with border
int squareBitmapWidth = Math.min(srcBitmap.getWidth(), srcBitmap.getHeight());
// Initialize a new instance of Bitmap
Bitmap dstBitmap = Bitmap.createBitmap (
squareBitmapWidth, // Width
squareBitmapWidth, // Height
Bitmap.Config.ARGB_8888 // Config
);
Canvas canvas = new Canvas(dstBitmap);
// Initialize a new Paint instance
Paint paint = new Paint();
paint.setAntiAlias(true);
Rect rect = new Rect(0, 0, squareBitmapWidth, squareBitmapWidth);
RectF rectF = new RectF(rect);
canvas.drawOval(rectF, paint);
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
// Calculate the left and top of copied bitmap
float left = (squareBitmapWidth-srcBitmap.getWidth())/2;
float top = (squareBitmapWidth-srcBitmap.getHeight())/2;
canvas.drawBitmap(srcBitmap, left, top, paint);
// Free the native object associated with this bitmap.
srcBitmap.recycle();
// Return the circular bitmap
return dstBitmap;
}
// Custom method to add a border around circular bitmap
protected Bitmap addBorderToCircularBitmap(Bitmap srcBitmap, int borderWidth, int borderColor) {
// Calculate the circular bitmap width with border
int dstBitmapWidth = srcBitmap.getWidth()+borderWidth*2;
// Initialize a new Bitmap to make it bordered circular bitmap
Bitmap dstBitmap = Bitmap.createBitmap(dstBitmapWidth,dstBitmapWidth, Bitmap.Config.ARGB_8888);
// Initialize a new Canvas instance
Canvas canvas = new Canvas(dstBitmap);
// Draw source bitmap to canvas
canvas.drawBitmap(srcBitmap, borderWidth, borderWidth, null);
// Initialize a new Paint instance to draw border
Paint paint = new Paint();
paint.setColor(borderColor);
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeWidth(borderWidth);
paint.setAntiAlias(true);
canvas.drawCircle(
canvas.getWidth() / 2, // cx
canvas.getWidth() / 2, // cy
canvas.getWidth()/2 - borderWidth / 2, // Radius
paint // Paint
);
// Free the native object associated with this bitmap.
srcBitmap.recycle();
// Return the bordered circular bitmap
return dstBitmap;
}
// Custom method to add a shadow around circular bitmap
protected Bitmap addShadowToCircularBitmap(Bitmap srcBitmap, int shadowWidth, int shadowColor){
// Calculate the circular bitmap width with shadow
int dstBitmapWidth = srcBitmap.getWidth()+shadowWidth*2;
Bitmap dstBitmap = Bitmap.createBitmap(dstBitmapWidth,dstBitmapWidth, Bitmap.Config.ARGB_8888);
// Initialize a new Canvas instance
Canvas canvas = new Canvas(dstBitmap);
canvas.drawBitmap(srcBitmap, shadowWidth, shadowWidth, null);
// Paint to draw circular bitmap shadow
Paint paint = new Paint();
paint.setColor(shadowColor);
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeWidth(shadowWidth);
paint.setAntiAlias(true);
// Draw the shadow around circular bitmap
canvas.drawCircle (
dstBitmapWidth / 2, // cx
dstBitmapWidth / 2, // cy
dstBitmapWidth / 2 - shadowWidth / 2, // Radius
paint // Paint
);
srcBitmap.recycle();
return dstBitmap;
}
}Step 4 − Add the following code to Manifests/AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.medkart.sample"> <application android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:roundIcon="@mipmap/ic_launcher_round" android:supportsRtl="true" android:theme="@style/AppTheme"> <activity android:name=".MainActivity"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application> </manifest>
Let's try to run your application. I assume you have connected your actual Android Mobile device with your computer. To run the app from android studio, open one of your project's activity files and Click Run 
Icon from the toolbar. Select your mobile device as an option and then check your mobile device which will display your default screen –
Click here to download the project code.
Updated on: 03-Jul-2020
844 Views
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