Source

File: wp-admin/includes/image.php

function _wp_image_meta_replace_original( $saved_data, $original_file, $image_meta, $attachment_id ) {
	$new_file = $saved_data['path'];

	// Update the attached file meta.
	update_attached_file( $attachment_id, $new_file );

	// Width and height of the new image.
	$image_meta['width']  = $saved_data['width'];
	$image_meta['height'] = $saved_data['height'];

	// Make the file path relative to the upload dir.
	$image_meta['file'] = _wp_relative_upload_path( $new_file );

	// Store the original image file name in image_meta.
	$image_meta['original_image'] = wp_basename( $original_file );

	return $image_meta;
}