/** * 缩略图(按等比例,根据设置的宽度和高度进行裁剪) */ private function _thumb() { //如果原图本身小于缩略图，按原图长高 if ($this->newWidth > $this->width) $this->newWidth = $this->width; if ($this->newHeight > $this->height) $this->newHeight = $this->height; //背景图长高 $gd_width = $this->newWidth; $gd_height = $this->newHeight; //如果缩略图宽高，其中有一边等于原图的宽高，就直接裁剪 if ($gd_width == $this->width || $gd_height == $this->height) { $this->newWidth = $this->width; $this->newHeight = $this->height; } else { //计算缩放比率 $per = 1; if (($this->newHeight / $this->height) > ($this->newWidth / $this->width)) { $per = $this->newHeight / $this->height; } else { $per = $this->newWidth / $this->width; } if ($per < 1) { $this->newWidth = $this->width * $per; $this->newHeight = $this->height * $per; } } $this->newImg = $this->_CreateImg($gd_width, $gd_height, $this->type); imagecopyresampled($this->newImg, $this->img, 0, 0, 0, 0, $this->newWidth, $this->newHeight, $this->width, $this->height); }
生成缩略图函数_thumb() ，是按照前面的分析来进行编码。
5.3. 添加水印图片函数 _addWaterMark()
/** * 添加水印 */ private function _addWaterMark() { $ratio = 1 / 5; //水印缩放比率 $Width = imagesx($this->newImg); $Height = imagesy($this->newImg); $n_width = $Width * $ratio; $n_height = $Width * $ratio; list($markWidth, $markHeight, $markType) = getimagesize($this->waterMarkPath); if ($n_width > $markWidth) $n_width = $markWidth; if ($n_height > $markHeight) $n_height = $markHeight; $Img = $this->_loadImg($this->waterMarkPath, $markType); $Img = $this->_thumb1($Img, $markWidth, $markHeight, $markType, $n_width, $n_height); $markWidth = imagesx($Img); $markHeight = imagesy($Img); imagecopyresampled($this->newImg, $Img, $Width - $markWidth - 10, $Height - $markHeight - 10, 0, 0, $markWidth, $markHeight, $markWidth, $markHeight); imagedestroy($Img); }
在添加水印图片中，用到一个_thumb1()函数来缩放水印图片：
/** * 缩略图(按等比例) * @param resource $img 图像流 * @param int $width * @param int $height * @param int $type * @param int $new_width * @param int $new_height * @return resource */ private function _thumb1($img, $width, $height, $type, $new_width, $new_height) { if ($width < $height) { $new_width = ($new_height / $height) * $width; } else { $new_height = ($new_width / $width) * $height; } $newImg = $this->_CreateImg($new_width, $new_height, $type); imagecopyresampled($newImg, $img, 0, 0, 0, 0, $new_width, $new_height, $width, $height); return $newImg; }
5.4. 完整代码：
<?php /** * 图片处理，生成缩略图和添加水印图片 * Created by PhpStorm. * User: andy * Date: 17-1-3 * Time: 上午11:55 */ class Image { //原图 private $imgPath; //图片地址 private $width; //图片宽度 private $height; //图片高度 private $type; //图片类型 private $img; //图片(图像流) //缩略图 private $newImg; //缩略图(图像流) private $newWidth; private $newHeight; //水印图路径 private $waterMarkPath; //输出图像质量,jpg有效 private $quality; /** * Image constructor. * @param string $imagePath 图片路径 * @param string $markPath 水印图片路径 * @param int $new_width 缩略图宽度 * @param int $new_height 缩略图高度 * @param int $quality JPG图片格输出质量 */ public function __construct(string $imagePath, string $markPath = null, int $new_width = null, int $new_height = null, int $quality = 75) { $this->imgPath = $_SERVER['DOCUMENT_ROOT'] . $imagePath; $this->waterMarkPath = $markPath; $this->newWidth = $new_width ? $new_width : $this->width; $this->newHeight = $new_height ? $new_height : $this->height; $this->quality = $quality ? $quality : 75; list($this->width, $this->height, $this->type) = getimagesize($this->imgPath); $this->img = $this->_loadImg($this->imgPath, $this->type); //生成缩略图 $this->_thumb(); //添加水印图片 if (!empty($this->waterMarkPath)) $this->_addWaterMark(); //输出图片 $this->_outputImg(); } /** *图片输出 */ private function _outputImg() { switch ($this->type) { case 1: // GIF imagegif($this->newImg, $this->imgPath); break; case 2: // JPG if (intval($this->quality) < 0 || intval($this->quality) > 100) $this->quality = 75; imagejpeg($this->newImg, $this->imgPath, $this->quality); break; case 3: // PNG imagepng($this->newImg, $this->imgPath); break; } imagedestroy($this->newImg); imagedestroy($this->img); } /** * 添加水印 */ private function _addWaterMark() { $ratio = 1 / 5; //水印缩放比率 $Width = imagesx($this->newImg); $Height = imagesy($this->newImg); $n_width = $Width * $ratio; $n_height = $Width * $ratio; list($markWidth, $markHeight, $markType) = getimagesize($this->waterMarkPath); if ($n_width > $markWidth) $n_width = $markWidth; if ($n_height > $markHeight) $n_height = $markHeight; $Img = $this->_loadImg($this->waterMarkPath, $markType); $Img = $this->_thumb1($Img, $markWidth, $markHeight, $markType, $n_width, $n_height); $markWidth = imagesx($Img); $markHeight = imagesy($Img); imagecopyresampled($this->newImg, $Img, $Width - $markWidth - 10, $Height - $markHeight - 10, 0, 0, $markWidth, $markHeight, $markWidth, $markHeight); imagedestroy($Img); } /** * 缩略图(按等比例,根据设置的宽度和高度进行裁剪) */ private function _thumb() { //如果原图本身小于缩略图，按原图长高 if ($this->newWidth > $this->width) $this->newWidth = $this->width; if ($this->newHeight > $this->height) $this->newHeight = $this->height; //背景图长高 $gd_width = $this->newWidth; $gd_height = $this->newHeight; //如果缩略图宽高，其中有一边等于原图的宽高，就直接裁剪 if ($gd_width == $this->width || $gd_height == $this->height) { $this->newWidth = $this->width; $this->newHeight = $this->height; } else { //计算缩放比率 $per = 1; if (($this->newHeight / $this->height) > ($this->newWidth / $this->width)) { $per = $this->newHeight / $this->height; } else { $per = $this->newWidth / $this->width; } if ($per < 1) { $this->newWidth = $this->width * $per; $this->newHeight = $this->height * $per; } } $this->newImg = $this->_CreateImg($gd_width, $gd_height, $this->type); imagecopyresampled($this->newImg, $this->img, 0, 0, 0, 0, $this->newWidth, $this->newHeight, $this->width, $this->height); } /** * 缩略图(按等比例) * @param resource $img 图像流 * @param int $width * @param int $height * @param int $type * @param int $new_width * @param int $new_height * @return resource */ private function _thumb1($img, $width, $height, $type, $new_width, $new_height) { if ($width < $height) { $new_width = ($new_height / $height) * $width; } else { $new_height = ($new_width / $width) * $height; } $newImg = $this->_CreateImg($new_width, $new_height, $type); imagecopyresampled($newImg, $img, 0, 0, 0, 0, $new_width, $new_height, $width, $height); return $newImg; } /** * 加载图片 * @param string $imgPath * @param int $type * @return resource */ private function _loadImg($imgPath, $type) { switch ($type) { case 1: // GIF $img = imagecreatefromgif($imgPath); break; case 2: // JPG $img = imagecreatefromjpeg($imgPath); break; case 3: // PNG $img = imagecreatefrompng($imgPath); break; default: //其他类型 Tool::alertBack('不支持当前图片类型.' . $type); break; } return $img; } /** * 创建一个背景图像 * @param int $width * @param int $height * @param int $type * @return resource */ private function _CreateImg($width, $height, $type) { $img = imagecreatetruecolor($width, $height); switch ($type) { case 3: //png imagecolortransparent($img, 0); //设置背景为透明的 imagealphablending($img, false); imagesavealpha($img, true); break; case 4://gif imagecolortransparent($img, 0); break; } return $img; } }
6.调用
调用非常简单，在引入类后，直接new 并输入对应参数即可：
e.g.
new Image($_path, MARK, 400, 200, 100);