Resize images with PHP

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 100x100 thumb, which is saved to the Server for reuse at a later date

Have you tried Imagine? It meets all your requirements.

I had used it once (however for a very simple image manipulation) and it turend out to be a pretty useful and easy-to-use library.

Override must be accessed via RequestOptions in the most recent version of Glide 4.x. You can add RequestOptions through apply()

Glide
    .with(context)
    .load(path)
    .apply(new RequestOptions().override(600, 200))
    .into(imageViewResizeCenterCrop);