Yii - ImageCache

<?php
...
'image'=>array(
        'class'=>'ext.imageapi.CImage',
        'presets'=>array(
            '640x480'=>array(
                'cacheIn'=>'webroot.repository.640x480',
                'actions'=>array(
                    'scaleAndCrop'=>array('width'=>640,
                                          'height'=>480),
                    'watermark'=>array(
                       'pngWatermark'=>'webroot.images.watermark.png',
                        'x'=>590,'y'=>430),
                ),
            ),
            '100x75'=>array(
                'cacheIn'=>'webroot.repository.100x75',
                'actions'=>array(
                    'scaleAndCrop'=>array('width'=>100, 'height'=>75),
                    'watermark'=>array('pngWatermark'=>'/images/watermark.png', 'x'=>50,'y'=>25),
                ),
            ),
            '40x30'=>array(
                'cacheIn'=>'webroot.repository.40x30',
                'actions'=>array( 'scaleAndCrop'=>array('width'=>40, 'height'=>30) ),
            ),
            '27x20'=>array(
                'cacheIn'=>'webroot.repository.27x20',
                'actions'=>array( 'scaleAndCrop'=>array('width'=>27, 'height'=>20) ),
            ),
      ),
    ),