Get width height of image using Varien-image class in Magento

You can get width height of image using Varien_Image (lib/Varien/Image.php) class object. In this example, I assume that your image is present inside media directory of your magento installation. $imagePath = YOUR_IMAGE_PATH_LINK; // like http://example.com/media/myfolder/myimage.jpg // changing url link of image into directory link $dirImg = Mage::getBaseDir().str_replace("/",DS,strstr($imagePath,'/media')); // getting image width and height if (file_exists($dirImg)) { $imageObj = new Varien_Image($dirImg); $width = $imageObj->getOriginalWidth(); $height = $imageObj->getOriginalHeight(); echo $width." x ".$height; } else { echo "File doesn't exist."; }



Resize Image

<?php echo $this->helper('catalog/image')->init($_product, 'image')

->constrainOnly(TRUE)

->keepAspectRatio(TRUE)

->keepFrame(FALSE)

->resize(600,null)

?>

Fixed height of 600px

<?php echo $this->helper('catalog/image')->init($_product, 'image')

->constrainOnly(TRUE)

->keepAspectRatio(TRUE)

->keepFrame(FALSE)

->resize(null,600)

?>

The following code will resize image proportionally and not let the image be greater than height and width specified.

<?php echo $this->helper('catalog/image')->init($_product, 'image')

->constrainOnly(TRUE)

->keepAspectRatio(TRUE)

->keepFrame(FALSE)

->resize(400,400)

?>

Description of the functions used above:-
constrainOnly(bool $flag)
Guarantee, that image picture will not be bigger, than it was. Applicable before calling resize() It is false by default
keepAspectRatio(bool $flag) 
Guarantee, that image picture width/height will not be distorted. Applicable before calling resize() It is true by default.
keepFrame(bool $flag) 
Guarantee, that image will have dimensions, set in $width/$height. Applicable before calling resize() Not applicable, if keepAspectRatio(false).
You can resize image with Varien_Image class as well. This is most suitable when you are resizing image that is not related with catalog product.

// actual path of image

$imageUrl = Mage::getBaseDir('media').DS."myimage".DS.$post->getThumbnail();

// path of the resized image to be saved

// here, the resized image is saved in media/resized folder

$imageResized = Mage::getBaseDir('media').DS."myimage".DS."resized".DS.$post->getThumbnail();

// resize image only if the image file exists and the resized image file doesn't exist

// the image is resized proportionally with the width/height 135px

if (!file_exists($imageResized)&&file_exists($_imageUrl)) :

$imageObj = new Varien_Image($_imageUrl);

$imageObj->constrainOnly(TRUE);

$imageObj->keepAspectRatio(TRUE);

$imageObj->keepFrame(FALSE);

$imageObj->resize(135, 135);

$imageObj->save($imageResized);

endif;

You can use the resized image now as:

<img src="<?php echo Mage::getBaseUrl('media')."myimage/resized/".$post->getThumbnail() ?>" />

Another Scenario
Suppose, you have an image link. Now, you want to resize it. The image might be from any place. In this example, I am supposing the image link to be like http://localhost/magento/media/catalog/category/test_image.jpg
Now, I have to resize it. To do so, I will create a directory called resized inside media/catalog/category. And, I will save the resized file into the newly created resized directory.

// my sample image

$imageUrl ="http://localhost/magento/media/catalog/category/test_image.jpg";

// create folder

if(!file_exists("./media/catalog/category/resized"))     mkdir("./media/catalog/category/resized",0777);

// get image name

$imageName = substr(strrchr($imageUrl,"/"),1);

// resized image path (media/catalog/category/resized/IMAGE_NAME)

$imageResized = Mage::getBaseDir('media').DS."catalog".DS."category".DS."resized".DS.$imageName;

// changing image url into direct path

$dirImg = Mage::getBaseDir().str_replace("/",DS,strstr($imageUrl,'/media'));

// if resized image doesn't exist, save the resized image to the resized directory

if (!file_exists($imageResized)&&file_exists($dirImg)) :

$imageObj = new Varien_Image($dirImg);

$imageObj->constrainOnly(TRUE);

$imageObj->keepAspectRatio(TRUE);

$imageObj->keepFrame(FALSE);

$imageObj->resize(120, 120);

$imageObj->save($imageResized);

endif;

$newImageUrl = Mage::getBaseUrl('media')."catalog/category/resized/".$imageName;

Displaying newly created resized image.

<img src="<?php echo Mage::getBaseUrl('media')."catalog/category/resized/".$newImageUrl ?>" />

You can check other function for Varien_Image at
http://docs.magentocommerce.com/Varien/elementindex_Varien_Image.html
http://blog.chapagain.com.np/