How to resize product/custom image in magento

>> Resize product image with product object.

          <img src="<?php echo Mage::helper('catalog/image')->init($_product, 'image')->resize(70,155);?>"/>


>> Resize a custom Image.

        // Image name
        $image = "";

        // actual image path
        $imageUrl = Mage::getBaseDir('media'). DS .'justonestepsolution'. DS .$image;
    
        // Give resized image path to be saved
        // here, the resized image will save in media/justonestepsolution/resized folder
        $imageResized = Mage::getBaseDir('media'). DS .'justonestepsolution'. DS .'resized'. DS .$image;
    
        // image will resize only if the image file exists and the resized image file doesn't exist

        if (!file_exists($imageResized) && file_exists($imageUrl))
        {
            $imageObj = new Varien_Image($imageUrl);
            $imageObj->constrainOnly(TRUE);
            $imageObj->keepAspectRatio(TRUE);
            $imageObj->keepFrame(FALSE);
            $imageObj->resize(300, null);
            $imageObj->save($imageResized);
        }


enjoy :-)