The Android Image Cropper library, available at GitHub, provides flexible image cropping capabilities.

Setup

Add the dependency to your build.gradle file:

implementation 'com.theartofdev.edmodo:android-image-cropper:2.4.+'

Add the required permissions to your AndroidManifest.xml:

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

Usage Approaches

Activity-based Cropping

1. Register the cropping activity in AndroidManifest.xml:

<activity android:name="com.theartofdev.edmodo.cropper.CropImageActivity"/>

2. Launch the cropping activity with your image URI:

CropImage.activity(imageUri)
    .setGuidelines(CropImageView.Guidelines.ON)
    .start(this);

3. Handle the result in onActivityResult:

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == CropImage.CROP_IMAGE_ACTIVITY_REQUEST_CODE) {
        CropImage.ActivityResult result = CropImage.getActivityResult(data);
        if (resultCode == RESULT_OK) {
            Uri croppedUri = result.getUri();
        } else if (resultCode == CropImage.CROP_IMAGE_ACTIVITY_RESULT_ERROR_CODE) {
            Exception error = result.getError();
        }
    }
}

View-based Cropping

1. Add the CropImageView directly to you're layout:

<com.theartofdev.edmodo.cropper.CropImageView
    xmlns:custom="http://schemas.android.com/apk/res-auto"
    android:id="@+id/cropImageView"
    android:layout_width="match_parent"
    android:layout_height="0dp"
    android:layout_weight="1" />

2. Load an image into the view:

cropImageView.setImageBitmap(bitmap);
// or
cropImageView.setImageUriAsync(uri);

3. Retrieve the cropped image:

Bitmap cropped = cropImageView.getCroppedImage();
// or
cropImageView.setOnCropImageCompleteListener(listener);
cropImageView.getCroppedImageAsync();

For further details, refer to the official documentation on the GitHub project page.