Drupal Migrate class for creating image entities.

ExampleImageMigration.php

<?php

/**
 * Migrate images into entities.
 */
class ExampleImageMigration extends Migration {

  /**
   * {@inheritdoc}
   */
  public function __construct($arguments) {
    parent::__construct($arguments);
    $this->description = t('Creates image entities.');

    // Set the source.
    $this->source = new ExampleMigrateSourceImage();

    // Set the destination.
    $this->destination = new MigrateDestinationNode('image');

    // Build a migration map.
    $this->map = new MigrateSQLMap($this->machineName,
      array(
        'id' => array(
          'type' => 'varchar',
          'length' => 255,
          'not null' => TRUE,
          'description' => t('Image URL'),
        ),
      ),
      MigrateDestinationNode::getKeySchema()
    );

    // Title.
    $this->addFieldMapping('title', 'node_title');

    // Credit.
    $this->addFieldMapping('field_image_credit', 'credit');
    $this->addFieldMapping('field_image_credit:format')
         ->defaultValue('filtered_html');

    // Alt text.
    $this->addFieldMapping('field_image_alt_text', 'alt');

    // Title text.
    $this->addFieldMapping('field_image_title_text', 'title');

    // Image file.
    $this->addFieldMapping('field_image_master', 'url');
    $this->addFieldMapping('field_image_master:destination_file', 'filename');
    $this->addFieldMapping('field_image_master:file_replace')
         ->defaultValue(FILE_EXISTS_RENAME);
    $this->addFieldMapping('field_image_master:destination_dir')
         ->defaultValue('public://images');

    // Status.
    $this->addFieldMapping('status')
         ->defaultValue(NODE_PUBLISHED);

    // Author.
    $this->addFieldMapping('uid')
         ->defaultValue(1);

    // Sticky.
    $this->addFieldMapping('sticky')
         ->defaultValue(NODE_NOT_STICKY);

    // Pathauto.
    $this->addFieldMapping('pathauto')
         ->defaultValue(TRUE);

    // Verify that all unmapped fields are set to DNM here.
  }

  /**
   * {@inheritdoc}
   */
  public function prepareRow($row) {
    if (parent::prepareRow($row) === FALSE) {
      return FALSE;
    }

    // Add optional fallback node title value logic here that would set the
    // value for $row->node_title if it was empty.

    // Add optional logic here to verify that we have a valid image URL.
  }

}