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

//指定圖片路徑
$src = '001.png';
//獲取圖片信息
$info = getimagesize($src);
//獲取圖片擴展名
$type = image_type_to_extension($info[2],false);
//動態(tài)的把圖片導(dǎo)入內(nèi)存中
$fun = "imagecreatefrom{$type}";
$image = $fun('001.png');
//指定字體顏色
$col = imagecolorallocatealpha($image,255,255,255,50);
//指定字體內(nèi)容
$content = 'helloworld';
//給圖片添加文字
imagestring($image,5,20,30,$content,$col);
//指定輸入類型
header('Content-type:'.$info['mime']);
//動態(tài)的輸出圖片到瀏覽器中
$func = "image{$type}";
$func($image);
//銷毀圖片
imagedestroy($image);

2:Object-oriented implementation method

class Image_class {
  private $image;
  private $info;

  /**
   * @param $src:圖片路徑
   * 加載圖片到內(nèi)存中
   */
  function __construct($src){
    $info = getimagesize($src);
    $type = image_type_to_extension($info[2],false);
    $this -> info =$info;
    $this->info['type'] = $type;
    $fun = "imagecreatefrom" .$type;
    $this -> image = $fun($src);
  }

  /**
   * @param $fontsize: 字體大小
   * @param $x: 字體在圖片中的x位置
   * @param $y: 字體在圖片中的y位置
   * @param $color: 字體的顏色是一個包含rgba的數(shù)組
   * @param $text: 想要添加的內(nèi)容
   * 操作內(nèi)存中的圖片,給圖片添加文字水印
   */
  public function fontMark($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);
  }
  /*
   * 輸出圖片到瀏覽器中
   */
  public function show(){
    header('content-type:' . $this -> info['mime']);
    $fun='image' . $this->info['type'];
    $fun($this->image);
  }

  /**
   * 銷毀圖片
   */
  function __destruct(){
    imagedestroy($this->image);
  }
}
//對類的調(diào)用
$obj = new Image_class('001.png');
$obj->fontMark(20,20,30,array(255,255,255,60),'hello');
$obj->show();

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("不支持的圖片文件類型"); 
      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("不支持的水印圖片文件類型"); 
        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("不支持的水印圖片文件類型"); 
      exit; 
  }
    
  imagedestroy($dst_img);
  imagedestroy($srcim);
}

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
/*給圖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()--從字符串中的圖像流新建一個圖像，返回一個圖像標(biāo)示符，其表達了從給定字符串得來的圖像
圖像格式將自動監(jiān)測，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)
$img由圖像創(chuàng)建函數(shù)返回的圖像資源
size要使用的水印的字體大小
angle（角度）文字的傾斜角度，如果是0度代表文字從左往右，如果是90度代表從上往下
x,y水印文字的第一個文字的起始位置
color是水印文字的顏色
fontfile，你希望使用truetype字體的路徑*/
list($dst_w,$dst_h,$dst_type) = getimagesize($dst_path);
/*list(mixed $varname[,mixed $......])--把數(shù)組中的值賦給一些變量
像array()一樣，這不是真正的函數(shù)，而是語言結(jié)構(gòu)，List()用一步操作給一組變量進行賦值*/
/*getimagesize()能獲取到什么信息？
getimagesize函數(shù)會返回圖像的所有信息，包括大小，類型等等*/
switch($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($dst);
    break;
  default:
    break;
  /*imagepng--以PNG格式將圖像輸出到瀏覽器或文件
  imagepng()將GD圖像流(image)以png格式輸出到標(biāo)注輸出（通常為瀏覽器），或者如果用filename給出了文件名則將其輸出到文件*/
}
imagedestroy($dst);
?>

Summary: The above is the entire content of this article, I hope it will be helpful to everyone's study.

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