时间:2021-07-01 10:21:17 帮助过:47人阅读
本文实例讲述了PHP生成图片缩略图类。分享给大家供大家参考,具体如下:
- class App_image_helper {
- protected $imgFileName;
- protected $imgWidth;
- protected $imgHeight;
- protected $imgMime;
- protected $imgResource;
- static $imgMineList
- = array(
- 'jpeg' => 'image/jpeg',
- 'gif' => 'image/gif',
- 'png' => 'image/png',
- 'wbmp' => 'image/wbmp',
- );
- /**
- * 根据文件名,初始化图片,
- * 计算出给定图片的宽、高、图片类型,并获取图片的资源保存到内存,便于下次使用
- * App_image_helper constructor.
- *
- * @param $fileName
- */
- public function __construct($fileName) {
- $this->imgFileName = $fileName;
- list($this->imgWidth, $this->imgHeight, $this->imgMime) = $this->getImageInfo($this->imgFileName);
- $this->imgResource = $this->getImageResource($this->imgFileName);
- }
- /**
- * 根据图片路径获取相关宽、高、MIME类型信息
- *
- * @param $fileName
- *
- * @return array|null
- */
- protected function getImageInfo($fileName) {
- $result = null;
- if ( is_file($fileName) ) {
- $tmpImageInfo = getimagesize($fileName);
- if ( $tmpImageInfo ) {
- $result = array($tmpImageInfo[0], $tmpImageInfo[1], $tmpImageInfo['mime']);
- }
- }
- return $result;
- }
- /**
- * 将图片文件转为资源类类型
- *
- * @param $fileName
- *
- * @return null|resource
- */
- protected function getImageResource($fileName) {
- $image = null;
- if ( is_file($fileName) ) {
- switch ($this->imgMime) {
- case self::$imgMineList['jpeg']:
- $image = imagecreatefromjpeg($fileName);
- break;
- case self::$imgMineList['gif']:
- $image = imagecreatefromgif($fileName);
- break;
- case self::$imgMineList['png']:
- $image = imagecreatefrompng($fileName);
- break;
- case self::$imgMineList['wbmp']:
- $image = imagecreatefromwbmp($fileName);
- break;
- default:
- break;
- }
- }
- return $image;
- }
- /**
- * 可根据固定宽,等比缩放图片;或根据百分比,等比缩放图片
- *
- * @param int $width
- * @param int $percent
- *
- * @return array|null
- */
- protected function getSizeByScale($width = 360, $percent = 1) {
- $result = null;
- if ( $this->imgWidth && $this->imgHeight ) {
- if ( $width ) {
- $result = array($width, intval($width * $this->imgHeight / $this->imgWidth));
- } elseif ( $percent ) {
- $result = array(intval($this->imgWidth * $percent), intval($this->imgHeight * $percent));
- }
- }
- return $result;
- }
- /**
- * 外调
- *
- * @param int $percentOrWidth int整数表示图片缩放为固定宽度,0.0~0.99999表示缩放百分比
- * @param null $fileName
- * @param int $quality
- * @param bool $reSample 重新采样图片,默认是
- *
- * @return bool
- */
- public function createImage($percentOrWidth = 1, $fileName = null, $quality = 75, $reSample = true) {
- $result = false;
- $fileName ? header('Content-Type: ' . $this->imgMime) : false;
- $size = $this->getSizeByScale(($percentOrWidth <= 1) ? null : $percentOrWidth, $percentOrWidth);
- if ( $size ) {
- $thumb = imagecreatetruecolor($size[0], $size[1]);
- if ( $reSample ) {
- imagecopyresampled($thumb, $this->imgResource, 0, 0, 0, 0, $size[0], $size[1], $this->imgWidth, $this->imgHeight);
- } else {
- imagecopyresized($thumb, $this->imgResource, 0, 0, 0, 0, $size[0], $size[1], $this->imgWidth, $this->imgHeight);
- }
- $result = imagejpeg($thumb, $fileName, $quality);
- }
- return $result;
- }
- }
PS:这里再为大家推荐几款比较实用的图片处理工具供大家参考使用:
在线图片转换BASE64工具:
http://tools.jb51.net/transcoding/img2base64
ICO图标在线生成工具:
http://tools.jb51.net/aideddesign/ico_img
在线Email邮箱图标制作工具:
http://tools.jb51.net/email/emaillogo
在线图片格式转换(jpg/bmp/gif/png)工具:
http://tools.jb51.net/aideddesign/picext
更多关于PHP相关内容感兴趣的读者可查看本站专题:《PHP图形与图片操作技巧汇总》、《PHP基本语法入门教程》、《PHP运算与运算符用法总结》、《php面向对象程序设计入门教程》、《PHP网络编程技巧总结》、《PHP数组(Array)操作技巧大全》、《php字符串(string)用法总结》、《php+mysql数据库操作入门教程》及《php常见数据库操作技巧汇总》
希望本文所述对大家PHP程序设计有所帮助。