How to Pass Bitmaps between Activities in Android Studio

When working with images in Android applications, there are several scenarios where you may need to pass a bitmap from one activity to another. However, it's essential to understand that bitmaps can consume significant memory and can cause your application to slow down or even crash if not handled properly.

In this article, we will discuss how to pass a bitmap between activities in Android Studio while minimizing the impact on performance.

Limitations of Bitmap Size

When passing a bitmap from one activity to another, it's crucial to keep the size of the bitmap as small as possible. A good rule of thumb is to ensure that the bitmap does not exceed an icon size (32x32 pixels). This can be achieved by compressing the image file before sending it over.

Passing Bitmaps between Activities

To pass a bitmap from Activity A to Activity B, you can use the Intent mechanism in Android. In Activity A, you can decode your image and send it via intent as follows:

```

Bundle extras = getIntent().getExtras();

byte'' b = extras.getByteArray('picture');

Bitmap bmp = BitmapFactory.decodeByteArray(b, 0, b.length);

Intent intent = new Intent(this, ActivityB.class);

intent.putExtra('picture', bmp);

startActivity(intent);

```

In Activity B, you can receive the intent with a byte array (decoded picture) and apply it as a source to an ImageView:

```

Bundle extras = getIntent().getExtras();

byte'' b = extras.getByteArray('picture');

Bitmap bmp = BitmapFactory.decodeByteArray(b, 0, b.length);

ImageView image = (ImageView) findViewById(R.id.imageView1);

image.setImageBitmap(bmp);

```

Alternative Method: Compressing Bitmaps

Another method to pass a bitmap between activities is by compressing the image file before sending it over. This approach can be useful when you need to reduce the size of the bitmap even further.

Here's an example of how to compress a bitmap:

```

Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);

ByteArrayOutputStream baos = new ByteArrayOutputStream();

bitmap.compress(Bitmap.CompressFormat.PNG, 100, baos);

byte'' b = baos.toByteArray();

Intent intent = new Intent(this, ActivityB.class);

intent.putExtra('picture', b);

startActivity(intent);

```

In this example, we compress the bitmap using PNG compression with a quality of 100. The resulting byte array can be sent over to another activity.

Passing bitmaps between activities in Android Studio requires careful consideration of the image size and compression methods. By following the guidelines outlined in this article, you can ensure that your application runs smoothly while passing images between activities. Remember to keep the size of the bitmap as small as possible and use appropriate compression methods to minimize memory consumption.

Android studio intent bitmap