diff --git a/config/schema/google_vision.schema.yml b/config/schema/google_vision.schema.yml
index 76f0c1a..07850ab 100644
--- a/config/schema/google_vision.schema.yml
+++ b/config/schema/google_vision.schema.yml
@@ -24,3 +24,6 @@ field.field.*.*.*.third_party.google_vision:
     emotion_detect:
       type: boolean
       label: 'Emotion Detection'
+    google_vision:
+      type: boolean
+      label: 'Google Vision'
diff --git a/google_vision.module b/google_vision.module
index 859a724..551e03b 100644
--- a/google_vision.module
+++ b/google_vision.module
@@ -10,7 +10,7 @@ use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Entity\EntityTypeInterface;
 use Drupal\Core\Field\FieldItemListInterface;
 use Drupal\Core\Field\FieldDefinitionInterface;
-
+use Drupal\taxonomy\Entity\Vocabulary;
 /**
  * Implements hook_entity_presave().
  */
@@ -35,7 +35,7 @@ function google_vision_entity_presave(EntityInterface $entity) {
             //Use a new taxonomy vocabulary to group the objects by their dominant color.
             $new_vid = "dominant_color";
             $name = "Dominant Color";
-            $vocabularies = \Drupal\taxonomy\Entity\Vocabulary::loadMultiple();
+            $vocabularies = Vocabulary::loadMultiple();
             // Create a vocabulary if not already present.
             if (!isset($vocabularies[$new_vid])) {
               $vocabulary = \Drupal\taxonomy\Entity\Vocabulary::create(array(
@@ -45,7 +45,9 @@ function google_vision_entity_presave(EntityInterface $entity) {
               ));
               $vocabulary->save();
             }
-            google_vision_file_entity_dominant_color($entity, $field, $new_vid);
+            if (!empty($field->getSettings()['handler_settings']['target_bundles']['dominant_color'])) {
+              google_vision_file_entity_dominant_color($entity, $field, $new_vid);
+            }
           }
         }
       }
diff --git a/google_vision.services.yml b/google_vision.services.yml
index be39f19..91ddb31 100644
--- a/google_vision.services.yml
+++ b/google_vision.services.yml
@@ -1,4 +1,4 @@
 services:
   google_vision.api:
     class: Drupal\google_vision\GoogleVisionAPI
-    arguments: ['@config.factory', '@http_client']
\ No newline at end of file
+    arguments: ['@config.factory', '@http_client']
diff --git a/src/Controller/SimilarContentController.php b/src/Controller/SimilarContentController.php
index 9006afe..e16df87 100644
--- a/src/Controller/SimilarContentController.php
+++ b/src/Controller/SimilarContentController.php
@@ -9,21 +9,38 @@ use Symfony\Component\DependencyInjection\ContainerInterface;
 use Drupal\Core\Render\BareHtmlPageRendererInterface;
 use Drupal\Core\Url;
 use Drupal\Core\Entity\EntityInterface;
+use Drupal\taxonomy\Entity\Term;
+use Drupal\Core\Database\Connection;
 
 /**
-* Returns the related content based on dominant color of the images.
-*/
+ * Returns the related content based on dominant color of the images.
+ */
 class SimilarContentController extends ControllerBase {
   /**
+   * Database Service Object.
+   *
+   * @var \Drupal\Core\Database\Connection
+   */
+  protected $connection;
+
+  /**
+   * Constructs a SimilarContentController object.
+   */
+  public function __construct(Connection $connection) {
+    $this->connection = $connection;
+  }
+
+  /**
    * Get the file title.
    */
   public function getFileTitle($fid) {
-    $query = \Drupal::database()->select('file_managed', 'fm');
+    $query = $this->connection->select('file_managed', 'fm');
     $query->fields('fm', ['filename']);
     $query->condition('fm.fid', $fid);
     $title = $query->execute()->fetchField();
     return $title;
   }
+
   /**
    * Returns the list of image links which share the same dominant color.
    */
@@ -33,41 +50,56 @@ class SimilarContentController extends ControllerBase {
 
     //Get an array of just term ids.
     $query = \Drupal::entityQuery('taxonomy_term');
-    $query->condition('vid', "dominant_color");
+    $query->condition('vid', 'dominant_color');
     $tids = $query->execute();
-    $terms = \Drupal\taxonomy\Entity\Term::loadMultiple($tids);
+    $terms = Term::loadMultiple($tids);
     $term_id = array_keys($terms);
 
     // Get the list of dominant colors per file.
     $dominant_color = [];
     foreach ($term_id as $key => $value) {
-      $query = \Drupal::database()->select('file__field_labels', 'ffl');
+      $query = $this->connection->select('file__field_labels', 'ffl');
       $query->fields('ffl', ['field_labels_target_id']);
       $query->condition('ffl.entity_id', $file_id);
       $query->condition('ffl.field_labels_target_id', $value);
       $dominant_color[] = $query->execute()->fetchField();
     }
 
+    $build = array();
+
+    if (!empty($dominant_color)) {
     //Get all the file ids which have one or more dominant colors in common with $dominant_color.
-    $query = \Drupal::database()->select('file__field_labels', 'ffl');
-    $query->fields('ffl', ['entity_id', 'field_labels_target_id']);
-    $query->condition('field_labels_target_id', $dominant_color, 'IN');
-    $files = $query->execute()->fetchAllKeyed();
+      $query = $this->connection->select('file__field_labels', 'ffl');
+      $query->fields('ffl', ['entity_id', 'field_labels_target_id']);
+      $query->condition('field_labels_target_id', $dominant_color, 'IN');
+      $files = $query->execute()->fetchAllKeyed();
 
-    $build = array();
-    $build['#prefix'] = '<ul>';
-    $build['#suffix'] = '</ul>';
+      $build['#prefix'] = '<ul>';
+      $build['#suffix'] = '</ul>';
 
-    foreach ($files as $key => $value) {
-      $build[$key] = [
+      foreach ($files as $key => $value) {
+        $build[$key] = [
         '#prefix' => '<li>',
         '#type' => 'link',
         '#title' => $this->getFileTitle($key),
         '#url' => Url::fromRoute('entity.file.canonical', ['file' => $key]),
         '#suffix' => '</li>',
+        ];
+      }
+    }
+    else {
+      $build = [
+        '#markup' => t('No items found.'),
       ];
     }
 
     return $build;
   }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container) {
+    return new static($container->get('database'));
+  }
 }
diff --git a/src/Tests/SimilarContentsTest.php b/src/Tests/SimilarContentsTest.php
new file mode 100644
index 0000000..1e6070d
--- /dev/null
+++ b/src/Tests/SimilarContentsTest.php
@@ -0,0 +1,205 @@
+<?php
+
+namespace Drupal\google_vision\Tests;
+
+use Drupal\Core\Url;
+use Drupal\simpletest\WebTestBase;
+use Drupal\file_entity\Entity\FileEntity;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\Core\Language\LanguageInterface;
+use Drupal\taxonomy\Entity\Vocabulary;
+
+/**
+ * Tests whether the similar contents are displayed for the image files or not.
+ *
+ * @group google_vision
+ */
+class SimilarContentsTest extends WebTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static $modules = [
+    'google_vision',
+    'google_vision_test',
+    'field_ui',
+    'field',
+    'file',
+    'taxonomy',
+    'entity_reference',
+  ];
+
+  /**
+   * A user with permission to create content and upload images.
+   *
+   * @var object
+   */
+  protected $adminUser;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+
+    //Creates an administrator user.
+    $this->adminUser = $this->drupalCreateUser([
+      'administer google vision',
+      'administer files',
+      'edit any image files',
+      'create files',
+      'administer file types',
+      'administer file fields',
+      'administer taxonomy',
+    ]);
+    $this->drupalLogin($this->adminUser);
+    //Check whether the API key is set.
+    $this->drupalGet(Url::fromRoute('google_vision.settings'));
+    $this->assertNotNull('api_key', 'The api key is set');
+  }
+
+  /**
+   * Uploads an image file and saves it.
+   *
+   * @param integer $count
+   *  The index for the image file.
+   *
+   * @return integer
+   *  The file id of the newly created image file.
+   */
+  public function uploadImageFile($count) {
+    $images = $this->drupalGetTestFiles('image');
+    $edit = [
+      'files[upload]' => \Drupal::service('file_system')->realpath($images[$count]->uri),
+    ];
+    $this->drupalPostForm('file/add', $edit, t('Next'));
+    $this->drupalPostForm(NULL, array(), t('Next'));
+    $this->drupalPostForm(NULL, array(), t('Save'));
+    return (int) db_query('SELECT MAX(fid) FROM {file_managed}')->fetchField();
+  }
+
+  /**
+   * Creates a new field for referencing taxonomy vocabulary.
+   *
+   * @param \Drupal\taxonomy\Entity\Vocabulary $vocabulary.
+   *  The vocabulary.
+   */
+  public function createEntityReferenceField($vocabulary) {
+    $entity_type = 'taxonomy_term';
+    $field_name = 'field_labels';
+    $field_storage = FieldStorageConfig::create(array(
+      'field_name' => $field_name,
+      'entity_type' => 'file',
+      'translatable' => FALSE,
+      'settings' => array(
+        'target_type' => $entity_type,
+      ),
+      'type' => 'entity_reference',
+      'cardinality' => 1,
+    ));
+    $field_storage->save();
+    $field = FieldConfig::create(array(
+      'field_storage' => $field_storage,
+      'entity_type' => 'file',
+      'bundle' => 'image',
+      'settings' => array(
+        'handler' => 'default',
+        'handler_settings' => array(
+          // Restrict selection of terms to a single vocabulary.
+          'target_bundles' => array(
+            $vocabulary->id() => $vocabulary->id(),
+          ),
+        ),
+      ),
+    ));
+    $field->save();
+  }
+
+  /**
+   * Creates and returns a new vocabulary.
+   *
+   * @param string $name.
+   *  The name for the created vocabulary.
+   *
+   * @param string $vid.
+   *  The vocabulary id.
+   *
+   * @return \Drupal\taxonomy\Entity\Vocabulary $vocabulary.
+   *  The vocabulary.
+   */
+  function createTaxonomyVocabulary($name, $vid) {
+    $vocabulary = Vocabulary::create([
+      'name' => $name,
+      'description' => t('Stores the dominant color of the images.'),
+      'vid' => $vid,
+      'langcode' => LanguageInterface::LANGCODE_NOT_SPECIFIED,
+    ]);
+    $vocabulary->save();
+    return $vocabulary;
+  }
+
+  /**
+   * Test to ensure that the Similar Contents contains the related images.
+   */
+  public function testSimilarContents() {
+    $name = 'Dominant Color';
+    $vid = 'dominant_color';
+    $count = 0;
+    $vocabulary = $this->createTaxonomyVocabulary($name, $vid);
+    //Check whether the vocabulary is created.
+    $this->drupalGet(Url::fromRoute('entity.taxonomy_vocabulary.collection'));
+    $this->assertResponse(200);
+    //Create a taxonomy reference field.
+    $this->createEntityReferenceField($vocabulary);
+    $edit = [
+      'google_vision' => 1,
+      'settings[handler_settings][auto_create]' => 1,
+    ];
+    $this->drupalPostForm('admin/structure/file-types/manage/image/edit/fields/file.image.field_labels', $edit, t('Save settings'));
+    //Ensure that the Dominant Color option is selected.
+    $this->drupalGet('admin/structure/file-types/manage/image/edit/fields/file.image.field_labels');
+    // Upload an image file.
+    $file_id = $this->uploadImageFile($count);
+
+    //Create multiple images to be displayed in the similar contents link.
+    for ($count=1; $count < 3; $count++) {
+      $id[$count] = $this->uploadImageFile($count);
+    }
+    $this->drupalGet('file/' . $file_id . '/similarcontent');
+    $this->assertResponse(200);
+    $this->assertNoText('No items found.', 'Similar Contents are displayed.');
+  }
+
+  /**
+   * Test to ensure that no similar images are present.
+   */
+  public function testNoSimilarContents() {
+    $name = 'Labels';
+    $vid = 'other_labels';
+    $count = 0;
+    $vocabulary = $this->createTaxonomyVocabulary($name, $vid);
+    //Check whether the vocabulary is created.
+    $this->drupalGet(Url::fromRoute('entity.taxonomy_vocabulary.collection'));
+    $this->assertResponse(200);
+    //Create a taxonomy reference field.
+    $this->createEntityReferenceField($vocabulary);
+    $edit = [
+      'google_vision' => 1,
+      'settings[handler_settings][auto_create]' => 1,
+    ];
+    $this->drupalPostForm('admin/structure/file-types/manage/image/edit/fields/file.image.field_labels', $edit, t('Save settings'));
+    //Ensure that the Dominant Color option is not selected.
+    $this->drupalGet('admin/structure/file-types/manage/image/edit/fields/file.image.field_labels');
+    // Upload an image file.
+    $file_id = $this->uploadImageFile($count);
+
+    //Create multiple images to be displayed in the similar contents link.
+    for ($count=1; $count < 3; $count++) {
+      $id[$count] = $this->uploadImageFile($count);
+    }
+    $this->drupalGet('file/' . $file_id . '/similarcontent');
+    $this->assertResponse(200);
+    $this->assertText('No items found.', 'No items found message is displayed.');
+  }
+}
diff --git a/tests/modules/google_vision_test/src/GoogleVisionAPIFake.php b/tests/modules/google_vision_test/src/GoogleVisionAPIFake.php
index c35f123..e426967 100644
--- a/tests/modules/google_vision_test/src/GoogleVisionAPIFake.php
+++ b/tests/modules/google_vision_test/src/GoogleVisionAPIFake.php
@@ -49,6 +49,31 @@ class GoogleVisionAPIFake extends GoogleVisionAPI {
   }
 
   /**
+   * Function to retrieve labels for given image.
+   *
+   * @param string $filepath .
+   *
+   * @return Array|bool.
+   */
+  public function labelDetection($filepath) {
+    if (!$this->apiKey) {
+      return FALSE;
+    }
+    $response = [
+      'responses' => [
+        '0' => [
+          'labelAnnotations' => [
+            '0' => [
+              'description' => 'Sample Image',
+            ],
+          ],
+        ],
+      ],
+    ];
+    return $response;
+  }
+
+  /**
    * Function to return the response showing the image contains explicit content.
    *
    * @param string $filepath .
@@ -73,4 +98,37 @@ class GoogleVisionAPIFake extends GoogleVisionAPI {
     );
     return $response;
   }
+
+  /**
+   * Function to retrieve image attributes for given image.
+   *
+   * @param string $filepath .
+   *
+   * @return Array|bool.
+   */
+  public function imageAttributesDetection($filepath) {
+    if (!$this->apiKey) {
+      return FALSE;
+    }
+    $response = [
+      'responses' => [
+        '0' => [
+          'imagePropertiesAnnotation' => [
+            'dominantColors' => [
+              'colors' => [
+                '0' => [
+                  'color' => [
+                    'red' => 124,
+                    'blue' => 159,
+                    'green' => 20,
+                  ],
+                ],
+              ],
+            ],
+          ],
+        ],
+      ],
+    ];
+    return $response;
+  }
 }