Mask your image with different shapes and dimension. More option coming in future.
-Developed and tested with Yii 1.1.12 but may working with older versions too. -PHP GD library enabled.
Extract the source file into protected/extensions folder.
Simply put this below widget in view file:
$this->widget('ext.imagemask.ImageMask', array( 'shape' => 'round', 'imgpath' => Yii::app()->basePath.'/../images/mango.jpg', 'width' => '200', 'height' => '200', 'title' => 'Sample Image', ));
Available shape: round, roundedsquare, polygon, oval.
...external resources for this extension...