PHP添加PNG图片背景透明水印操作类定义与用法示例

本文实例讲述了PHP添加PNG图片背景透明水印操作类定义与用法。分享给大家供大家参考，具体如下：

图片相关操作类

class ImageTool
{
  private $imagePath;//图片路径
  private $outputDir;//输出文件夹
  public $memoryImg;//内存图像
  public $path;
  public function __construct($imagePath, $outputDir = null)
  {
    $this->imagePath = $imagePath;
    $this->outputDir = $outputDir;
    $this->memoryImg = null;
    $this->path = null;
  }
  
  public function showImage()
  {
    if ($this->memoryImg != null) {
      $info = getimagesize($this->imagePath);
      $type = image_type_to_extension($info[2], false);
      header('Content-type:' . $info['mime']);
      $funs = "image{$type}";
      $funs($this->memoryImg);
      imagedestroy($this->memoryImg);
      $this->memoryImg = null;
    }
  }
  
  private function saveImage($image)
  {
    $info = getimagesize($this->imagePath);
    $type = image_type_to_extension($info[2], false);
    $funs = "image{$type}";
    if (empty($this->outputDir)) {
      $funs($image, md5($this->imagePath) . '.' . $type);
      return md5($this->imagePath) . '.' . $type;
    } else {
      $funs($image, $this->outputDir . md5($this->imagePath) . '.' . $type);
      return $this->outputDir . md5($this->imagePath) . '.' . $type;
    }
  }
  
  public function compressImage($width, $height, $output = false)
  {
    $image = null;
    $info = getimagesize($this->imagePath);
    $type = image_type_to_extension($info[2], false);
    $fun = "imagecreatefrom{$type}";
    $image = $fun($this->imagePath);
    imagesavealpha($image,true);//
    $thumbnail = imagecreatetruecolor($width, $height);
    imagealphablending($thumbnail,false);//这里很重要,意思是不合并颜色,直接用$img图像颜色替换,包括透明色;
    imagesavealpha($thumbnail,true);//
    imagecopyresampled($thumbnail, $image, 0, 0, 0, 0, $width, $height, $info[0], $info[1]);
    imagedestroy($image);
    if ($output) {
      $path = $this->saveImage($thumbnail);
      $this->path = $path;
    }
    $this->memoryImg = $thumbnail;
    return $this;
  }
  
  public function addTextmark($content, $size, $font, $output = false)
  {
    $info = getimagesize($this->imagePath);
    $type = image_type_to_extension($info[2], false);
    $fun = "imagecreatefrom{$type}";
    $image = $fun($this->imagePath);
    $color = imagecolorallocatealpha($image, 0, 0, 0, 80);
    $posX = imagesx($image) - strlen($content) * $size / 2;
    $posY = imagesy($image) - $size / 1.5;
    imagettftext($image, $size, 0, $posX, $posY, $color, $font, $content);
    if ($output) {
      $this->saveImage($image);
    }
    $this->memoryImg = $image;
    return $this;
  }
  
  public function addWatermark($watermark, $alpha, $output = false)
  {
    $image_info = getimagesize($this->imagePath);
    $image_type = image_type_to_extension($image_info[2], false);
    $image_fun = "imagecreatefrom{$image_type}";
    $image = $image_fun($this->imagePath);
    $mark_info = getimagesize($watermark);
    $mark_type = image_type_to_extension($mark_info[2], false);
    $mark_fun = "imagecreatefrom{$mark_type}";
    $mark = $mark_fun($watermark);
    $posX = imagesx($image) - imagesx($mark);
    $posY = imagesy($image) - imagesy($mark);
    imagesavealpha($mark, true);
    imagecopymerge($image, $mark, $posX, $posY, 0, 0, $mark_info[0], $mark_info[1], $alpha);
    imagesavealpha($mark, true);
    if ($output) {
      $path = $this->saveImage($image);
      $this->path = $path;
    }
    $this->memoryImg = $image;
    return $this;
  }
  //用给定角度旋转图像，以jpeg图像格式为例
  
  function rotateImage($degrees, $output = false)
  {
    $info = getimagesize($this->imagePath);
    $type = image_type_to_extension($info[2], false);
    $fun = "imagecreatefrom{$type}";
    $image = $fun($this->imagePath);
    $block = imagecreatetruecolor(170,170);//建立一个画板
    $bg = imagecolorallocatealpha($block , 0 , 0 , 0 , 127);//拾取一个完全透明的颜色
    $image = imagerotate($image, $degrees, $bg ,0);
    imagesavealpha($image, true);
    header("Content-type: image/{$type}");
    //旋转后的图片保存
    if ($output) {
      $path = $this->saveImage($image);
      $this->path = $path;
    }
    $this->memoryImg = $image;
    return $this;
  }
  
  public function mergerImg($bigImgPath, $smallImgPath, $width, $height, $bigImgPaths)
  {
    $image_kuang = imagecreatefromstring(file_get_contents($smallImgPath));
    $image_photo = imagecreatefromstring(file_get_contents($bigImgPath));
    //创建一个新的，和大图一样大的画布
    $image_3 = imageCreatetruecolor(imagesx($image_photo), imagesy($image_photo));
    //为真彩色画布创建白色背景，再设置为透明
    $color = imagecolorallocate($image_3, 255, 255, 255);
    imagefill($image_3, 0, 0, $color);
    imageColorTransparent($image_3, $color);
    
   imagecopyresampled($image_3,$image_photo,0,0,0,0,imagesx($image_photo),imagesy($image_photo),imagesx($image_photo),imagesy($image_photo));
    imagecopy($image_3,$image_kuang, $width,$height,0,0,imagesx($image_kuang),imagesy($image_kuang));
    //存储图片路径
    imagejpeg($image_3, $bigImgPaths);
    return $bigImgPaths;
  }
}

控制器调用方法

public function test()
{
  $bigImgPath = 'ren.jpg';//原图路径
  $waterImgPath = 'tae.png';//水印图路径
  $imageTool = new ImageTool($waterImgPath, 'tmp/');//图片路径、输出文件夹
  $smallImgPath = $imageTool->rotateImage(45, true)->path;//旋转
  $width = 0;//水印所在X坐标
  $height = 0;//水印所在Y坐标
  $bigImgPaths = 'new.png';//生成原图加水印新图路径
  $path = $this->mergerImg($bigImgPath, $smallImgPath, $width, $height, $bigImgPaths);
  return view('image', compact('path'));
}

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希望本文所述对大家PHP程序设计有所帮助。