diff --git a/core/lib/Drupal/Core/Image/ImageFactory.php b/core/lib/Drupal/Core/Image/ImageFactory.php
index 992a2e0..29c2870 100644
--- a/core/lib/Drupal/Core/Image/ImageFactory.php
+++ b/core/lib/Drupal/Core/Image/ImageFactory.php
@@ -89,7 +89,7 @@ public function get($source = NULL, $toolkit_id = NULL) {
     $toolkit_id = $toolkit_id ?: $this->toolkitId;
     $image = $this->toolkitManager->createInstance($toolkit_id);
     if ($source) {
-      $image->parseFile($source);
+      $image->createFromSource($source);
     }
     return $image;
   }
diff --git a/core/lib/Drupal/Core/Image/ImageInterface.php b/core/lib/Drupal/Core/Image/ImageInterface.php
index b630c3d..ad3c241 100644
--- a/core/lib/Drupal/Core/Image/ImageInterface.php
+++ b/core/lib/Drupal/Core/Image/ImageInterface.php
@@ -13,18 +13,22 @@
 interface ImageInterface {
 
   /**
-   * Determines if a file contains a valid image.
+   * Gets an image from a file.
    *
    * Drupal supports GIF, JPG and PNG file formats when used with the GD
    * toolkit, and may support others, depending on which toolkits are
    * installed.
    *
-   * @param @todo
+   * @param string $source
+   *   The path to an image file.
+   *
+   * @throws \BadMethodCallException
+   *   When called twice.
    *
    * @return bool
    *   TRUE if the file could be found and is an image, FALSE otherwise.
    */
-  public function parseFile($source);
+  public function createFromSource($source);
 
   /**
    * Checks if the image is valid.
@@ -94,7 +98,7 @@ public function getSource();
   public function apply($operation, array $arguments = array());
 
   /**
-   * Closes the image and saves the changes to a file.
+   * Saves the image to a file.
    *
    * @param string|null $destination
    *   (optional) Destination path where the image should be saved. If it is empty
@@ -102,8 +106,6 @@ public function apply($operation, array $arguments = array());
    *
    * @return bool
    *   TRUE on success, FALSE on failure.
-   *
-   * @see \Drupal\Core\ImageToolkit\ImageToolkitInterface::save()
    */
   public function save($destination = NULL);
 
diff --git a/core/lib/Drupal/Core/ImageToolkit/ImageToolkitBase.php b/core/lib/Drupal/Core/ImageToolkit/ImageToolkitBase.php
index b2e944e..5de368c 100644
--- a/core/lib/Drupal/Core/ImageToolkit/ImageToolkitBase.php
+++ b/core/lib/Drupal/Core/ImageToolkit/ImageToolkitBase.php
@@ -104,16 +104,35 @@ public function validateConfigurationForm(array &$form, FormStateInterface $form
   /**
    * {@inheritdoc}
    */
-  public final function parseFile($source) {
+  public final function createFromSource($source) {
+    if ($this->getSource()) {
+      throw new \BadMethodCallException(__METHOD__ . '() may only be called once');
+    }
     $this->source = $source;
-    if ($this->doParseFile()) {
-      $this->fileSize = filesize($this->source);
+    if ($this->doCreateFromSource()) {
+      $this->fileSize = filesize($this->getSource());
       return TRUE;
     }
     return FALSE;
   }
 
   /**
+   * Performs toolkit specific operations to get an image from a file.
+   *
+   * Image toolkits must implement this method to ensure that the image
+   * can be manipulated through image toolkit operations once the source
+   * file is processed, and that
+   * \Drupal\Core\ImageToolkit\ImageToolkitInterface::isValid() will return
+   * TRUE if the image creation is successful.
+   *
+   * @return bool
+   *   TRUE if the file could be found and is an image, FALSE otherwise.
+   *
+   * @see \Drupal\Core\ImageToolkit\ImageToolkitInterface::isValid()
+   */
+  abstract protected function doCreateFromSource();
+
+  /**
    * {@inheritdoc}
    */
   public final function save($destination = NULL) {
@@ -138,6 +157,20 @@ public function validateConfigurationForm(array &$form, FormStateInterface $form
   }
 
   /**
+   * Performs toolkit specific operations to save an image to a file.
+   *
+   * Image toolkits must implement this method to ensure that the image
+   * is saved to a destination file.
+   *
+   * @param string $destination
+   *   Destination path where the image should be saved.
+   *
+   * @return bool
+   *   TRUE on success, FALSE on failure.
+   */
+  abstract protected function doSave($destination);
+
+  /**
    * Provides a wrapper for drupal_chmod() to allow unit testing.
    *
    * @param string $uri
diff --git a/core/lib/Drupal/Core/ImageToolkit/ImageToolkitInterface.php b/core/lib/Drupal/Core/ImageToolkit/ImageToolkitInterface.php
index 509c18b..38ec0c6 100644
--- a/core/lib/Drupal/Core/ImageToolkit/ImageToolkitInterface.php
+++ b/core/lib/Drupal/Core/ImageToolkit/ImageToolkitInterface.php
@@ -9,7 +9,6 @@
 
 use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
 use Drupal\Core\Plugin\PluginFormInterface;
-use Drupal\Core\Image\ImageInterface;
 use Drupal\Component\Plugin\PluginInspectionInterface;
 
 /**
diff --git a/core/modules/system/src/Plugin/ImageToolkit/GDToolkit.php b/core/modules/system/src/Plugin/ImageToolkit/GDToolkit.php
index a2190d7..7780fad 100644
--- a/core/modules/system/src/Plugin/ImageToolkit/GDToolkit.php
+++ b/core/modules/system/src/Plugin/ImageToolkit/GDToolkit.php
@@ -45,7 +45,7 @@ class GDToolkit extends ImageToolkitBase {
    *
    * @var array|null
    *
-   * @see \Drupal\system\Plugin\ImageToolkit\GDToolkit::parseFile()
+   * @see \Drupal\system\Plugin\ImageToolkit\GDToolkit::doCreateFromSource()
    * @see \Drupal\system\Plugin\ImageToolkit\GDToolkit::setResource()
    * @see http://php.net/manual/en/function.getimagesize.php
    */
@@ -199,7 +199,7 @@ protected function doSave($destination) {
   /**
    * {@inheritdoc}
    */
-  protected function doParseFile() {
+  protected function doCreateFromSource() {
     $data = @getimagesize($this->getSource());
     if ($data && in_array($data[2], static::supportedTypes())) {
       $this->setType($data[2]);
diff --git a/core/modules/system/tests/modules/image_test/src/Plugin/ImageToolkit/TestToolkit.php b/core/modules/system/tests/modules/image_test/src/Plugin/ImageToolkit/TestToolkit.php
index afbf105..8cd80b5 100644
--- a/core/modules/system/tests/modules/image_test/src/Plugin/ImageToolkit/TestToolkit.php
+++ b/core/modules/system/tests/modules/image_test/src/Plugin/ImageToolkit/TestToolkit.php
@@ -136,7 +136,7 @@ public function isValid() {
   /**
    * {@inheritdoc}
    */
-  protected function doParseFile() {
+  protected function doCreateFromSource() {
     $this->logCall('parseFile', func_get_args());
     $data = @getimagesize($this->getSource());
     if ($data && in_array($data[2], static::supportedTypes())) {
diff --git a/core/modules/system/tests/src/Unit/ImageToolkit/GDToolkitTest.php b/core/modules/system/tests/src/Unit/ImageToolkit/GDToolkitTest.php
index 931ba33..a6cf787 100644
--- a/core/modules/system/tests/src/Unit/ImageToolkit/GDToolkitTest.php
+++ b/core/modules/system/tests/src/Unit/ImageToolkit/GDToolkitTest.php
@@ -107,7 +107,7 @@ protected function getTestImage($load_expected = TRUE, array $stubs = array()) {
         ->method('load');
     }
 
-    $this->image->parseFile($this->source);
+    $this->image->createFromSource($this->source);
   }
 
   /**
@@ -128,7 +128,7 @@ protected function getTestImageForOperation($class_name) {
       ->method('getToolkitOperation')
       ->will($this->returnValue($this->toolkitOperation));
 
-    $this->image->parseFile($this->source);
+    $this->image->createFromSource($this->source);
   }
 
   /**
@@ -232,11 +232,11 @@ public function testChmodFails() {
   }
 
   /**
-   * @covers ::parseFile
+   * @covers ::createFromSource
    */
-  public function testParseFileFails() {
+  public function testCreateFromSourceFails() {
     $image = $this->getToolkitMock();
-    $image->parseFile('magic-foobars.png');
+    $image->createFromSource('magic-foobars.png');
 
     $this->assertFalse($image->isValid());
     $this->assertFalse($image->save());