Can't upload image with 100% quality – Photoshop

I’m gonna answer here because I don’t have enough reputation to make a comment.

To resize the image, i think it’s better to use the command imagescale. It’s better that use ImageCreateTrueColor + ImageCopyResampled.

So I’d do it

        // Resize
        if($this->resize)
        {
            $this->img_output = imagescale($this->img_input, $this->x_output, $this->y_output);

        }

But there are some other things that you also may change:

• I created the method create_thumbnail() and you’ll pass it the path to the image, the path where save the new image and optionally the size (Default 100).
• To have the width and the height, you don’t need to create the image. You can do it with the method getimagesize and like this, you’ll save a lot of resources.
• When you call the method to resize, it will resize the image if it needed.
• And when you are going to save the image, you can know if the image has been resized or not and so you’ll copy it or not.

Also, I’ve tried to not repeat any code and optimising the resources.

EDIT: Also you can clear the cache and the end of the process.

class imaging
{

    // Variables
    private $img_input;
    private $img_output;
    private $img_src;
    private $format;
    private $quality = 100;
    private $x_input;
    private $y_input;
    private $x_output;
    private $y_output;
    private $resize;

    // Set image
    public function upload($orig, $name, $path)
    {
        move_uploaded_file($orig, __DIR__ . "/../uploads/" . $path . 'orig_' . $name);
    }

        // Set image quality (JPEG only)
    public function set_quality($quality)
    {

        if(is_int($quality))
        {

            $this->quality = $quality;

        }

    }

    // Set maximum image size (pixels)
    private function resize($size = 100)
    {   
        $resize = FALSE; 
        // Wide
        if($this->x_input >= $this->y_input && $this->x_input > $size)
        {
            $this->x_output = $size;
            $this->y_output = ($this->x_output / $this->x_input) * $this->y_input;

            $resize = TRUE;
        }

        // Tall
        elseif($this->y_input > $this->x_input && $this->y_input > $size)
        {
            $this->y_output = $size;
            $this->x_output = ($this->y_output / $this->y_input) * $this->x_input;

            $resize = TRUE;
        }

        if($resize){

            switch ($this->format) {
                case 'JPEG':
                case 'JPG':
                    $this->img_input = ImageCreateFromJPEG($img);
                    break;
                case 'PNG':
                    $this->img_input = ImageCreateFromPNG($img);
                    break;
                case 'GIF':
                    $this->img_input = ImageCreateFromGIF($img);
                    break;
                
                default:
                    throw new Exception("This extension " . $ext . " it's not compatible.");
                    
                    break;
            }

        }

    }

    // Save image
    public function save_img($path)
    {
        // We have resized the image
        if($this->img_input){
            switch ($this->format) {
                case 'JPEG':
                case 'JPG':
                    imageJPEG($this->img_output, __DIR__ . "/../uploads/" . $path, $this->quality);
                    break;
                case 'PNG':
                    imagePNG( $this->img_output, __DIR__ . "/../uploads/" . $path, 9);
                    break;
                case 'GIF':
                    imageGIF( $this->img_output, __DIR__ . "/../uploads/" . $path);
                    break;
                
                default:
                    throw new Exception("This extension " . $ext . " it's not compatible.");
                    
                    break;
            }
        }else{
            copy($this->img_src, __DIR__ . "/../uploads/" . $path);
        }

    }

    public function create_thumbnail($imgSrc, $savePath, $size = 100)
    {
        $this->img_src = '../uploads/' . $img;

        if(file_exists($this->img_src)){
            list($this->x_input, $this->y_input) = getimagesize($imageSrc);
            $this->format = strtoupper(pathinfo($img, PATHINFO_EXTENSION));
            $this->resize($size);
            $this->save_img($savePath);
            $this->clear_cache();
        }else{
            throw new Exception("Image not found in " . $imdSrc);
        }

    }

    // Get width
    public function get_width()
    {

        return $this->x_input;

    }

    // Get height
    public function get_height()
    {

        return $this->y_input;

    }

    // Clear image cache
    public function clear_cache()
    {

        @ImageDestroy($this->img_input);
        @ImageDestroy($this->img_output);

    }

}