4 ways to add text watermarks to images in PHP-PHP Tutorial-php.cn

This article mainly introduces 4 ways to add text watermarks to images in PHP. Friends who are interested can refer to it. I hope it will be helpful to everyone.

1: Process-oriented writing method

//指定图片路径
$src = &#39;001.png&#39;;
//获取图片信息
$info = getimagesize($src);
//获取图片扩展名
$type = image_type_to_extension($info[2],false);
//动态的把图片导入内存中
$fun = "imagecreatefrom{$type}";
$image = $fun(&#39;001.png&#39;);
//指定字体颜色
$col = imagecolorallocatealpha($image,255,255,255,50);
//指定字体内容
$content = &#39;helloworld&#39;;
//给图片添加文字
imagestring($image,5,20,30,$content,$col);
//指定输入类型
header(&#39;Content-type:&#39;.$info[&#39;mime&#39;]);
//动态的输出图片到浏览器中
$func = "image{$type}";
$func($image);
//销毁图片
imagedestroy($image);

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2:Object-oriented implementation method

class Image_class {
  private $image;
  private $info;

  /**
   * @param $src:图片路径
   * 加载图片到内存中
   */
  function __construct($src){
    $info = getimagesize($src);
    $type = image_type_to_extension($info[2],false);
    $this -> info =$info;
    $this->info[&#39;type&#39;] = $type;
    $fun = "imagecreatefrom" .$type;
    $this -> image = $fun($src);
  }

  /**
   * @param $fontsize: 字体大小
   * @param $x: 字体在图片中的x位置
   * @param $y: 字体在图片中的y位置
   * @param $color: 字体的颜色是一个包含rgba的数组
   * @param $text: 想要添加的内容
   * 操作内存中的图片,给图片添加文字水印
   */
  public function fontMark($fontsize,$x,$y,$color,$text){
    $col = imagecolorallocatealpha($this->image,$color[0],$color[1],$color[2],$color[3]);
    imagestring($this->image,$fontsize,$x,$y,$text,$col);
  }
  /*
   * 输出图片到浏览器中
   */
  public function show(){
    header(&#39;content-type:&#39; . $this -> info[&#39;mime&#39;]);
    $fun=&#39;image&#39; . $this->info[&#39;type&#39;];
    $fun($this->image);
  }

  /**
   * 销毁图片
   */
  function __destruct(){
    imagedestroy($this->image);
  }
}
//对类的调用
$obj = new Image_class(&#39;001.png&#39;);
$obj->fontMark(20,20,30,array(255,255,255,60),&#39;hello&#39;);
$obj->show();

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3 .Supports adding watermark to pictures in two ways: pictures and text. Pictures support three formats: GIF, PNG, and JPG. Watermark pictures support PNG and GIF

function setWater($imgSrc,$markImg,$markText,$TextColor,$markPos,$fontType,$markType)
{

  $srcInfo = @getimagesize($imgSrc);
  $srcImg_w  = $srcInfo[0];
  $srcImg_h  = $srcInfo[1];
    
  switch ($srcInfo[2]) 
  { 
    case 1: 
      $srcim =imagecreatefromgif($imgSrc); 
      break; 
    case 2: 
      $srcim =imagecreatefromjpeg($imgSrc); 
      break; 
    case 3: 
      $srcim =imagecreatefrompng($imgSrc); 
      break; 
    default: 
      die("不支持的图片文件类型"); 
      exit; 
  }
    
  if(!strcmp($markType,"img"))
  {
    if(!file_exists($markImg) || empty($markImg))
    {
      return;
    }
      
    $markImgInfo = @getimagesize($markImg);
    $markImg_w  = $markImgInfo[0];
    $markImg_h  = $markImgInfo[1];
      
    if($srcImg_w < $markImg_w || $srcImg_h < $markImg_h)
    {
      return;
    }
      
    switch ($markImgInfo[2]) 
    { 
      case 1: 
        $markim =imagecreatefromgif($markImg); 
        break; 
      case 2: 
        $markim =imagecreatefromjpeg($markImg); 
        break; 
      case 3: 
        $markim =imagecreatefrompng($markImg); 
        break; 
      default: 
        die("不支持的水印图片文件类型"); 
        exit; 
    }
      
    $logow = $markImg_w;
    $logoh = $markImg_h;
  }
    
  if(!strcmp($markType,"text"))
  {
    $fontSize = 16;
    if(!empty($markText))
    {
      if(!file_exists($fontType))
      {
        return;
      }
    }
    else {
      return;
    }
      
    $box = @imagettfbbox($fontSize, 0, $fontType,$markText);
    $logow = max($box[2], $box[4]) - min($box[0], $box[6]);
    $logoh = max($box[1], $box[3]) - min($box[5], $box[7]);
  }
    
  if($markPos == 0)
  {
    $markPos = rand(1, 9);
  }
    
  switch($markPos)
  {
    case 1:
      $x = +5;
      $y = +5;
      break;
    case 2:
      $x = ($srcImg_w - $logow) / 2;
      $y = +5;
      break;
    case 3:
      $x = $srcImg_w - $logow - 5;
      $y = +15;
      break;
    case 4:
      $x = +5;
      $y = ($srcImg_h - $logoh) / 2;
      break;
    case 5:
      $x = ($srcImg_w - $logow) / 2;
      $y = ($srcImg_h - $logoh) / 2;
      break;
    case 6:
      $x = $srcImg_w - $logow - 5;
      $y = ($srcImg_h - $logoh) / 2;
      break;
    case 7:
      $x = +5;
      $y = $srcImg_h - $logoh - 5;
      break;
    case 8:
      $x = ($srcImg_w - $logow) / 2;
      $y = $srcImg_h - $logoh - 5;
      break;
    case 9:
      $x = $srcImg_w - $logow - 5;
      $y = $srcImg_h - $logoh -5;
      break;
    default: 
      die("此位置不支持"); 
      exit;
  }
    
  $dst_img = @imagecreatetruecolor($srcImg_w, $srcImg_h);
    
  imagecopy ( $dst_img, $srcim, 0, 0, 0, 0, $srcImg_w, $srcImg_h);
    
  if(!strcmp($markType,"img"))
  {
    imagecopy($dst_img, $markim, $x, $y, 0, 0, $logow, $logoh);
    imagedestroy($markim);
  }
    
  if(!strcmp($markType,"text"))
  {
    $rgb = explode(&#39;,&#39;, $TextColor);
      
    $color = imagecolorallocate($dst_img, $rgb[0], $rgb[1], $rgb[2]);
    imagettftext($dst_img, $fontSize, 0, $x, $y, $color, $fontType,$markText);
  }
    
  switch ($srcInfo[2]) 
  { 
    case 1:
      imagegif($dst_img, $imgSrc); 
      break; 
    case 2: 
      imagejpeg($dst_img, $imgSrc); 
      break; 
    case 3: 
      imagepng($dst_img, $imgSrc); 
      break;
    default: 
      die("不支持的水印图片文件类型"); 
      exit; 
  }
    
  imagedestroy($dst_img);
  imagedestroy($srcim);
}

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Parameter description:

$imgSrc: target picture, which can have a relative directory address,
$markImg : Watermark image, which can have a relative directory address and supports both PNG and GIF formats. For example, if the watermark image is in the mark directory of the executable file, it can be written as: mark/mark.gif
$markText: The watermark text added to the image
$TextColor: The font color of the watermark text
$markPos: The position where the image watermark is added, value range: 0~9
0: Random position, randomly select a position between 1~8
1 : Top left 2: Top center 3: Top right 4: Left center
5: Picture center 6: Right center 7: Bottom left 8: Bottom center 9: Bottom right
$fontType: Specific font library , can bring relative directory address
$markType: The way to add watermark to pictures, img means to add watermark in picture form, text means to add watermark in text form

4. How to add text watermark to picture

<?php
/*给图片加文字水印的方法*/
$dst_path = &#39;http://f4.topitme.com/4/15/11/1166351597fe111154l.jpg&#39;;
$dst = imagecreatefromstring(file_get_contents($dst_path));
/*imagecreatefromstring()--从字符串中的图像流新建一个图像，返回一个图像标示符，其表达了从给定字符串得来的图像
图像格式将自动监测，只要php支持jpeg,png,gif,wbmp,gd2.*/
 
$font = &#39;./t1.ttf&#39;;
$black = imagecolorallocate($dst, 0, 0, 0);
imagefttext($dst, 20, 0, 10, 30, $black, $font, &#39;Hello world!&#39;);
/*imagefttext($img,$size,$angle,$x,$y,$color,$fontfile,$text)
$img由图像创建函数返回的图像资源
size要使用的水印的字体大小
angle（角度）文字的倾斜角度，如果是0度代表文字从左往右，如果是90度代表从上往下
x,y水印文字的第一个文字的起始位置
color是水印文字的颜色
fontfile，你希望使用truetype字体的路径*/
list($dst_w,$dst_h,$dst_type) = getimagesize($dst_path);
/*list(mixed $varname[,mixed $......])--把数组中的值赋给一些变量
像array()一样，这不是真正的函数，而是语言结构，List()用一步操作给一组变量进行赋值*/
/*getimagesize()能获取到什么信息？
getimagesize函数会返回图像的所有信息，包括大小，类型等等*/
switch($dst_type){
  case 1://GIF
    header("content-type:image/gif");
    imagegif($dst);
    break;
  case 2://JPG
    header("content-type:image/jpeg");
    imagejpeg($dst);
    break;
  case 3://PNG
    header("content-type:image/png");
    imagepng($dst);
    break;
  default:
    break;
  /*imagepng--以PNG格式将图像输出到浏览器或文件
  imagepng()将GD图像流(image)以png格式输出到标注输出（通常为浏览器），或者如果用filename给出了文件名则将其输出到文件*/
}
imagedestroy($dst);
?>

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