Don’t know if someone has already sorted this out for you, but you need to edit the image-widget.php file.
Plugins > Editor > Image Widget > image-widget.php
Then copy this code:
<?php
/**
* Widget template. This template can be overriden using the "sp_template_image-widget_widget.php" filter.
* See the readme.txt file for more info.
*/
// Block direct requests
if ( !defined('ABSPATH') )
die('-1');
echo $before_widget;
if ( !empty( $image ) ) {
if ( $link ) {
echo '<a class="'.$this->widget_options['classname'].'-image-link" href="'.esc_url($link).'" target="'.esc_attr($linktarget).'">';
}
if ( $imageurl ) {
echo '<img src="'.esc_url($imageurl).'" style="';
if ( !empty( $width ) && is_numeric( $width ) ) {
echo "max-width: {$width}px;";
}
if ( !empty( $height ) && is_numeric( $height ) ) {
echo "max-height: {$height}px;";
}
echo "\"";
if ( !empty( $align ) && $align != 'none' ) {
$align = esc_attr($align);
echo " class=\"align{$align}\"";
}
if ( !empty( $alt ) ) {
$alt = esc_attr($alt);
echo " alt=\"{$alt}\"";
} else {
$title = esc_attr($title);
echo " alt=\"{$title}\"";
}
echo " />";
}
if ( $link ) { echo '</a>'; }
}
if ( !empty( $title ) ) { echo $before_title . $title . $after_title; }
if ( !empty( $description ) ) {
$text = apply_filters( 'widget_text', $description, $args, $instance );
echo '<div class="'.$this->widget_options['classname'].'-description" >';
echo wpautop( $text );
echo "</div>";
}
echo $after_widget;
?>