php thumbnail class (with calling example)

This article introduces a thumbnail class implemented in PHP that supports loading image files and image strings, proportional stretching, etc. There are calling examples behind the code for reference.

Share a php thumbnail class that can achieve the following functions:

1. Support loading image files and loading image strings 2. You can output thumbnails to the browser and keep thumbnail files 3. Support gif, png, jpeg type abbreviations 4. You can set whether to stretch proportionally

The code is as follows:

<?php
/**
 * 生成缩略图(支持加载图片文件和字符串2种方式)
 * @param       $maxWidth       缩略图最大宽度
 * @param       $maxHeight      缩略图最大高度
 * @param       bool    $scale  是否按比例缩小，否则拉伸
 * @param       bool    $inflate        是否放大以来填充缩略图
 * @edit by bbs.it-home.org
 */
class Thumbnail {
        private $maxWidth;
        private $maxHeight;
        private $scale;
        private $inflate;
        private $types;
        private $imgLoaders;
        private $imgCreators;
        private $source;
        private $sourceWidth;
        private $sourceHeight;
        private $sourceMime;
        private $thumb;
        private $thumbWidth;
        private $thumbHeight;

        public function __construct($maxWidth, $maxHeight, $scale = true, $inflate = true) {
                $this->maxWidth = $maxWidth;
                $this->maxHeight = $maxHeight;
                $this->scale = $scale;
                $this->inflate = $inflate;
                $this->types = array(
                    'image/jpeg',
                    'image/png',
                    'image/gif'
                );
                //加载MIME类型图像的函数名称
                $this->imgLoaders = array(
                    'image/jpeg'        =>      'imagecreatefromjpeg',
                    'image/png'         =>      'imagecreatefrompng',
                    'image/gif'         =>      'imagecreatefromgif'
                );
                //储存创建MIME类型图片的函数名称
                $this->imgCreators = array(
                    'image/jpeg'        =>      'imagejpeg',
                    'image/png'         =>      'imagepng',
                    'image/gif'         =>      'imagegif'
                );           
        }
        /**
         * 文件方式加载图片
         * @param       string  $image 源图片
         * @return      bool    
         */
        public function loadFile($image){
                if(!$dims = @getimagesize($image)){
                        trigger_error("源图片不存在");
                }
                if(in_array($dims['mime'], $this->types)){
                        $loader = $this->imgLoaders[$dims['mime']];
                        $this->source = $loader($image);
                        $this->sourceWidth = $dims[0];
                        $this->sourceHeight = $dims[1];
                        $this->sourceMime = $dims['mime'];
                        $this->initThumb();
                        return TRUE;
                }else{
                        trigger_error('不支持'.$dims['mime']."图片类型");
                }
        }
        /**
         * 字符串方式加载图片
         * @param       string $image  字符串
         * @param       string $mime    图片类型
         * @return type 
         */
        public function loadData($image,$mime){
                if(in_array($mime, $this->types)){
                        if($this->source = @imagecreatefromstring($image)){
                                $this->sourceWidth = imagesx($this->source);
                                $this->sourceHeight = imagesy($this->source);
                                $this->sourceMime = $mime;
                                $this->initThumb();
                                return TRUE;
                        }else{
                                trigger_error("不能从字符串加载图片");
                        }
                }else{
                        trigger_error("不支持".$mime."图片格式");
                }
        }
        /**
         * 生成缩略图
         * @param       string  $file   文件名。如果不为空则储存为文件，否则直接输出到浏览器
         */
        public function buildThumb($file = null){
                $creator = $this->imgCreators[$this->sourceMime];
                if(isset($file)){
                        return $creator($this->thumb,$file);
                }else{
                        return $creator($this->thumb);
                }
        }
        /**
         * 处理缩放
         */
        public function initThumb(){
                if($this->scale){
                        if($this->sourceWidth > $this->sourceHeight){
                                $this->thumbWidth = $this->maxWidth;
                                $this->thumbHeight = floor($this->sourceHeight*($this->maxWidth/$this->sourceWidth));
                        }elseif($this->sourceWidth < $this->sourceHeight){
                                $this->thumbHeight = $this->maxHeight;
                                $this->thumbWidth = floor($this->sourceWidth*($this->maxHeight/$this->sourceHeight));
                        }else{
                                $this->thumbWidth = $this->maxWidth;
                                $this->thumbHeight = $this->maxHeight;
                        }
                }
                $this->thumb = imagecreatetruecolor($this->thumbWidth, $this->thumbHeight);
                
                if($this->sourceWidth <= $this->maxWidth && $this->sourceHeight <= $this->maxHeight && $this->inflate == FALSE){
                        $this->thumb = $this->source;
                }else{
                        imagecopyresampled($this->thumb, $this->source, 0, 0, 0, 0, $this->thumbWidth, $this->thumbHeight, 
$this->sourceWidth, $this->sourceHeight);
                }
        }
        
        public function getMine(){
                return $this->sourceMime;
        }
        
        public function getThumbWidth(){
                return $this->thumbWidth;
        }
        
        public function getThumbHeight(){
                return $this->thumbHeight;
        }

}

/**
 * 缩略图类调用示例(文件)
 */
$thumb = new Thumbnail(200, 200);
$thumb->loadFile('wap.gif');
header('Content-Type:'.$thumb->getMine());
$thumb->buildThumb();
/**
 * 缩略图类调用示例(字符串)
 */
$thumb = new Thumbnail(200, 200);
$image = file_get_contents('wap.gif');
$thumb->loadData($image, 'image/jpeg');
$thumb->buildThumb('wap_thumb.gif');
?>