My (mostly technical) blog

I revisited the code I used to develop the old image resize component because I found a bug in the resize code. I used the resize function from the PImageComponent by Wendy and ended up with the current version I’m using at my websites:
Code download at the bottom of the post.

<?php
/*
 File: /app/controllers/components/image.php
*/
class ImageComponent extends Object
{
	/*
	*	Uploads an image and its thumbnail into $folderName/big and $folderName/small respectivley.
	* 	Also uploads a zoom cropped image into $folderName/home. You could easily modify it to suit your needs!

	* 	Directions:
	*	In view where you upload the image, make sure your form creation is similar to the following
	*	<?= $form->create('ControllerName',array('type' => 'file')); ?>

	*	In view where you upload the image, make sure that you have a file input similar to the following
	*	<?= $form->file('Image/image1'); ?>

	*	In the controller, add the component to your components array
	*	var $components = array("Image");

	*	In your controller action (the parameters are expained below)
	*	$image_path = $this->Image->upload_image_and_thumbnail($this->data,"name1", 573,380,80,80, "sets");
	*	this returns the file name of the result image.  You can  store this file name in the database
	*
	*	Note that your image will be stored in 3 locations:
	*	Image: /webroot/img/$folderName/big/$image_path
	*	Thumbnail:  /webroot/img/$folderName/small/$image_path
	*	Homepage:  /webroot/img/$folderName/home/$image_path
	*
	*	You could easily add more locations or remove locations you don't need

	*	Finally in the view where you want to see the images
	*	<?= $html->image('sets/big/'.$furnitureSet['FurnitureSet']['image_path']);
	* 	where "sets" is the folder name we saved our pictures in, and $furnitureSet['FurnitureSet']['image_path'] is the file name we stored in the database

	*	Parameters:
	*	$data: the image data array from the form
	*	$maxw: the maximum width that you want your picture to be resized to
	*	$maxh: the maximum width that you want your picture to be resized to
	*	$thumbscalew: the maximum width hat you want your thumbnail to be resized to
	*	$thumbscaleh: the maximum height that you want your thumbnail to be resized to
	*	$folderName: the name of the parent folder of the images. The images will be stored to /webroot/img/$folderName/big/ and  /webroot/img/$folderName/small/
	*/
	function upload_image_and_thumbnail($data, $maxw, $maxh, $thumbscalew, $thumbscaleh, $folderName) {
		if (strlen($data['name'])>4){
					$error = 0;
					$tempuploaddir = "img/temp"; // the /temp/ directory, should delete the image after we upload
					$homeuploaddir = "img/".$folderName."/home"; // the /home/ directory
					$biguploaddir = "img/".$folderName."/big"; // the /big/ directory
					$smalluploaddir = "img/".$folderName."/small"; // the /small/ directory for thumbnails

					// Make sure the required directories exist, and create them if necessary
					if(!is_dir($tempuploaddir)) mkdir($tempuploaddir,0755,true);
					if(!is_dir($homeuploaddir)) mkdir($homeuploaddir,0755,true);
					if(!is_dir($biguploaddir)) mkdir($biguploaddir,0755,true);
					if(!is_dir($smalluploaddir)) mkdir($smalluploaddir,0755,true);

					$filetype = $this->getFileExtension($data['name']);
					$filetype = strtolower($filetype);

					if (($filetype != "jpeg")  && ($filetype != "jpg") && ($filetype != "gif") && ($filetype != "png"))
					{
						// verify the extension
						return;
					}
					else
					{
						// Get the image size
						$imgsize = GetImageSize($data['tmp_name']);
					}

					// Generate a unique name for the image (from the timestamp)
					//$id_unic = str_replace(".", "", strtotime ("now"));
					$id_unic = $uuid = String::uuid();
					$filename = $id_unic;

					settype($filename,"string");
					$filename.= ".";
					$filename.=$filetype;
					$tempfile = $tempuploaddir . "/$filename";
					$homefile = $homeuploaddir . "/$filename";
					$resizedfile = $biguploaddir . "/$filename";
					$croppedfile = $smalluploaddir . "/$filename";

					if (is_uploaded_file($data['tmp_name']))
                    {
						// Copy the image into the temporary directory
                        if (!copy($data['tmp_name'],"$tempfile"))
                        {
                            //print "Error Uploading File!.";
							unset($filename);
							unlink($tempfile);
                            exit();
                        }
						else {
							/*
							 *	Generate the home page version of the image center cropped
							 */
							$this->resizeImage('resizeCrop', $tempuploaddir, $filename, $homeuploaddir, $filename, 886, 473, 85);
							/*
							 *	Generate the big version of the image with max of $imgscale in either directions
							 */
							$this->resizeImage('resize', $tempuploaddir, $filename, $biguploaddir, $filename, $maxw, $maxh, 85);							

							/*
							 *	Generate the small thumbnail version of the image with scale of $thumbscalew and $thumbscaleh
							 */
							$this->resizeImage('resizeCrop', $tempuploaddir, $filename, $smalluploaddir, $filename, $thumbscalew, $thumbscaleh, 75);

							// Delete the temporary image
							unlink($tempfile);
						}
                    }

                     // Image uploaded, return the file name
					 return $filename;
		}
	}

	/*
	*	Deletes the image and its associated thumbnail
	*	Example in controller action:	$this->Image->delete_image("1210632285.jpg","sets");
	*
	*	Parameters:
	*	$filename: The file name of the image
	*	$folderName: the name of the parent folder of the images. The images will be stored to /webroot/img/$folderName/big/ and  /webroot/img/$folderName/small/
	*/
	function delete_image($filename,$folderName) {
		if(is_file("img/".$folderName."/home/".$filename))
			unlink("img/".$folderName."/home/".$filename);
		if(is_file("img/".$folderName."/big/".$filename))
			unlink("img/".$folderName."/big/".$filename);
		if(is_file("img/".$folderName."/small/".$filename))
			unlink("img/".$folderName."/small/".$filename);
	}

    function getFileExtension($str) {

        $i = strrpos($str,".");
        if (!$i) { return ""; }
        $l = strlen($str) - $i;
        $ext = substr($str,$i+1,$l);
        return $ext;
    }

	/*
	 * @param $cType - the conversion type: resize (default), resizeCrop (square), crop (from center)
	 * @param $id - image filename
	 * @param $imgFolder  - the folder where the image is
	 * @param $newName - include extension (if desired)
	 * @param $newWidth - the  max width or crop width
	 * @param $newHeight - the max height or crop height
	 * @param $quality - the quality of the image
	 * @param $bgcolor - this was from a previous option that was removed, but required for backward compatibility
	 */
	function resizeImage($cType = 'resize', $srcfolder, $srcname, $dstfolder, $dstname = false, $newWidth=false, $newHeight=false, $quality = 75)
	{
		$srcimg = $srcfolder.DS.$srcname;
		list($oldWidth, $oldHeight, $type) = getimagesize($srcimg);
		$ext = $this->image_type_to_extension($type);

		//check to make sure that the file is writeable, if so, create destination image (temp image)
		if (is_writeable($dstfolder))
		{
			$dstimg = $dstfolder.DS.$dstname;
		}
		else
		{
			//if not let developer know
			debug("You must allow proper permissions for image processing. And the folder has to be writable.");
			debug("Run \"chmod 777 on '$dstfolder' folder\"");
			exit();
		}

		//check to make sure that something is requested, otherwise there is nothing to resize.
		//although, could create option for quality only
		if ($newWidth OR $newHeight)
		{
			/*
			 * check to make sure temp file doesn't exist from a mistake or system hang up.
			 * If so delete.
			 */
			if(file_exists($dstimg))
			{
				unlink($dstimg);
			}
			else
			{
				switch ($cType){
					default:
					case 'resize':
						# Maintains the aspect ration of the image and makes sure that it fits
						# within the maxW(newWidth) and maxH(newHeight) (thus some side will be smaller)
						$widthScale = 2;
						$heightScale = 2;

						// Check to see that we are not over resizing, otherwise, set the new scale
						if($newWidth) {
							if($newWidth > $oldWidth) $newWidth = $oldWidth;
							$widthScale = 	$newWidth / $oldWidth;
						}
						if($newHeight) {
							if($newHeight > $oldHeight) $newHeight = $oldHeight;
							$heightScale = $newHeight / $oldHeight;
						}
						//debug("W: $widthScale  H: $heightScale<br>");
						if($widthScale < $heightScale) {
							$maxWidth = $newWidth;
							$maxHeight = false;
						} elseif ($widthScale > $heightScale ) {
							$maxHeight = $newHeight;
							$maxWidth = false;
						} else {
							$maxHeight = $newHeight;
							$maxWidth = $newWidth;
						}

						if($maxWidth > $maxHeight){
							$applyWidth = $maxWidth;
							$applyHeight = ($oldHeight*$applyWidth)/$oldWidth;
						} elseif ($maxHeight > $maxWidth) {
							$applyHeight = $maxHeight;
							$applyWidth = ($applyHeight*$oldWidth)/$oldHeight;
						} else {
							$applyWidth = $maxWidth;
								$applyHeight = $maxHeight;
						}
						$startX = 0;
						$startY = 0;
						break;
					case 'resizeCrop':

						// Check to see that we are not over resizing, otherwise, set the new scale
						// -- resize to max, then crop to center
						if($newWidth > $oldWidth) $newWidth = $oldWidth;
							$ratioX = $newWidth / $oldWidth;

						if($newHeight > $oldHeight) $newHeight = $oldHeight;
							$ratioY = $newHeight / $oldHeight;									

						if ($ratioX < $ratioY) {
							$startX = round(($oldWidth - ($newWidth / $ratioY))/2);
							$startY = 0;
							$oldWidth = round($newWidth / $ratioY);
							$oldHeight = $oldHeight;
						} else {
							$startX = 0;
							$startY = round(($oldHeight - ($newHeight / $ratioX))/2);
							$oldWidth = $oldWidth;
							$oldHeight = round($newHeight / $ratioX);
						}
						$applyWidth = $newWidth;
						$applyHeight = $newHeight;
						break;
					case 'crop':
						// -- a straight centered crop
						$startY = ($oldHeight - $newHeight)/2;
						$startX = ($oldWidth - $newWidth)/2;
						$oldHeight = $newHeight;
						$applyHeight = $newHeight;
						$oldWidth = $newWidth;
						$applyWidth = $newWidth;
						break;
				}

				switch($ext)
				{
					case 'gif' :
						$oldImage = imagecreatefromgif($srcimg);
						break;
					case 'png' :
						$oldImage = imagecreatefrompng($srcimg);
						break;
					case 'jpg' :
					case 'jpeg' :
						$oldImage = imagecreatefromjpeg($srcimg);
						break;
					default :
						//image type is not a possible option
						return false;
						break;
				}

				//create new image
				$newImage = imagecreatetruecolor($applyWidth, $applyHeight);

				//put old image on top of new image
				imagecopyresampled($newImage, $oldImage, 0,0 , $startX, $startY, $applyWidth, $applyHeight, $oldWidth, $oldHeight);

					switch($ext)
					{
						case 'gif' :
							imagegif($newImage, $dstimg, $quality);
							break;
						case 'png' :
							imagepng($newImage, $dstimg, $quality);
							break;
						case 'jpg' :
						case 'jpeg' :
							imagejpeg($newImage, $dstimg, $quality);
							break;
						default :
							return false;
							break;
					}

				imagedestroy($newImage);
				imagedestroy($oldImage);

				return true;
			}

		} else {
			return false;
		}

	}

	function image_type_to_extension($imagetype)
	{
	if(empty($imagetype)) return false;
		switch($imagetype)
		{
			case IMAGETYPE_GIF    : return 'gif';
			case IMAGETYPE_JPEG    : return 'jpg';
			case IMAGETYPE_PNG    : return 'png';
			case IMAGETYPE_SWF    : return 'swf';
			case IMAGETYPE_PSD    : return 'psd';
			case IMAGETYPE_BMP    : return 'bmp';
			case IMAGETYPE_TIFF_II : return 'tiff';
			case IMAGETYPE_TIFF_MM : return 'tiff';
			case IMAGETYPE_JPC    : return 'jpc';
			case IMAGETYPE_JP2    : return 'jp2';
			case IMAGETYPE_JPX    : return 'jpf';
			case IMAGETYPE_JB2    : return 'jb2';
			case IMAGETYPE_SWC    : return 'swc';
			case IMAGETYPE_IFF    : return 'aiff';
			case IMAGETYPE_WBMP    : return 'wbmp';
			case IMAGETYPE_XBM    : return 'xbm';
			default                : return false;
		}
	}
	}
?>

to use it in your controller,

<?php
class FurnitureSetsController extends AppController {

	var $name = 'FurnitureSets';
var $components = array("Image","RequestHandler");

function admin_add() {
 if (!empty($this->data)) { 
  $this->FurnitureSet->create();
   if ($this->FurnitureSet->save($this->data)) {
    // resize the image to 573x380 and create a square thumbnail 80x80
       $image_path = $this->Image->upload_image_and_thumbnail($this->data,"name1", 573,380,80,80, "sets");
    if(isset($image_path)) {
     $this->FurnitureSet->saveField('image_path',$image_path);
    }
    else {
     $this->Session->setFlash(__('The image for the set could not be saved. Please, try again.', true));
    }     

   }

 }
}

Note that you can modify the resize settings in the upload_image_and_thumbnail method.

The view..

<div class="furnitureSets form">
    <?php echo $form->create('FurnitureSet',array('type' => 'file'));?>
    <fieldset>
        <legend>
            <?php __('Add Furniture set');?>
        </legend>
        <?php
		echo $form->input('name');
		echo $form->input('country_id');
			?>
		<div class="input">
		<label for="Image/name1">Image</label>
		<?php
		echo $form->file('Image/name1', array('size' => '40'));
		?>
		</div>
		<?php
		echo $form->input('is_featured');
		echo $form->input('furniture_material_id');
		echo $form->input('furniture_category_id');
		echo $form->input('is_indoor');
		echo $form->input('is_outdoor');
		echo $form->input('CustomerType');
	?>
    </fieldset>
    <?php echo $form->end('Submit');?>
</div>

Now as promised, the code!
30/4/2009: after modification from comments
17/7/2008: Old version

Again, thanks Wendy for your code!