Question

I have a quick question that I’m not quite sure to set up. I’ve seen examples elsewhere but nothing specifically like my situation. I would like to resize images using PHP so they’re readable and not just wonkily stretched like if you use HTML. If they’re not 250 pixels wide, or 160 pixels tall, how can I resize the picture so it’s proportionate but fits within that space?

Thanks!

Answer 1

Ok, so below is an Image object that I use in my store. It maintains scale – requires GD

<?php
class Store_Model_Image extends My_Model_Abstract 
{
    const PATH  = STORE_MODEL_IMAGE_PATH;
    const URL   = "/store-assets/product-images/";

    public function get_image_url($width, $height)
    {
        $old_file = self::PATH . $this->get_filename();
        $basename = pathinfo($old_file, PATHINFO_FILENAME);

        $new_name = sprintf("%s_%sx%s.jpg", $basename, $width, $height);
        if(file_exists(self::PATH . $new_name))
        {
            return self::URL . $new_name;
        }
        else
        {
            list($width_orig, $height_orig, $image_type) = @getimagesize($old_file);
            $img = FALSE;

            // Get the image and create a thumbnail     
            switch($image_type)
            {
                case 1:
                    $img = @imagecreatefromgif($old_file);
                    break;
                case 2:
                    $img = @imagecreatefromjpeg($old_file);
                    break;
                case 3: 
                    $img = @imagecreatefrompng($old_file);
                    break;
            }

            if(!$img)
            {
                throw new Zend_Exception("ERROR: Could not create image handle from path.");
            }

            // Build the thumbnail
            if($width_orig > $height_orig)
            {
                $width_ratio = $width / $width_orig;
                $new_width   = $width;
                $new_height  = $height_orig * $width_ratio;
            }
            else
            {
                $height_ratio = $height / $height_orig;
                $new_width    = $width_orig * $height_ratio;
                $new_height   = $height;
            }

            $new_img = @imagecreatetruecolor($new_width, $new_height);

            // Fill the image black
            if(!@imagefilledrectangle($new_img, 0, 0, $new_width, $new_height, 0))
            {           
                throw new Zend_Exception("ERROR: Could not fill new image");
            }

            if(!@imagecopyresampled($new_img, $img, 0, 0, 0, 0, $new_width, $new_height, $width_orig, $height_orig))
            {
                throw new Zend_Exception("ERROR: Could not resize old image onto new bg.");
            }

            // Use a output buffering to load the image into a variable
            ob_start();
            imagejpeg($new_img, NULL, 100);
            $image_contents = ob_get_contents();
            ob_end_clean();

            // lastly (for the example) we are writing the string to a file
            $fh = fopen(self::PATH . $new_name, "a+");
            fwrite($fh, $image_contents);
            fclose($fh);

            return self::URL . $new_name;
        }
    }
}

I resize the image at request time, so the first time the page loads an image will be resized to the required size for the template. (this means I don’t have to crash a shared host trying to regenerate image thumbnails everytime my design changes)

So in the template you pass your image object, and when you need a image thumb,

<img src="<?php echo $image->get_image_url(100, 100); ?>" />

you now have a 100×100 thumb, which is saved to the Server for reuse at a later date