PHP uses the imagick module to implement image scaling, cropping, and compression examples_PHP tutorial

/**
* Image processing service class
* Implemented using PHP extension service Imagick
* ImageMagick official website address [url]http:www.imagemagick.org/script/index.php[/url]
*
* @author weiguang3
* @since 20140403
*/
class ImagickService {
 private $image = null;
 private $type = null;

 // 构造函数
 public function __construct() {
 }

 // 析构函数
 public function __destruct() {
  if ($this->image !== null)
   $this->image->destroy ();
 }

 public function init(){

 }

 // 载入图像
 public function open($path) {
  $this->image = new Imagick ( $path );
  if ($this->image) {
   $this->type = strtolower ( $this->image->getImageFormat () );
  }
  return $this->image;
 }

 /**
* Image cropping
* Cropping rules:
* 1. The height is empty or zero. Scale the height to adapt according to the width.
* 2. The width is empty or zero. Scale the width to adapt according to the height. 🎜> * 3. The width and height must not be empty or zero. Scale and crop according to the width and height ratio. By default, crop from the center of the head
* @param number $width
* @param number $height
*/
 public function resize($width=0, $height=0){
  if($width==0 && $height==0){
   return;
  }

  $color = '';// 'rgba(255,255,255,1)';
  $size = $this->image->getImagePage ();
  //原始宽高
  $src_width = $size ['width'];
  $src_height = $size ['height'];

  //按宽度缩放 高度自适应
  if($width!=0 && $height==0){
   if($src_width>$width){
    $height = intval($width*$src_height/$src_width);

    if ($this->type == 'gif') {
     $this->_resizeGif($width, $height);
    }else{
     $this->image->thumbnailImage ( $width, $height, true );
    }
   }
   return;
  }
  //按高度缩放 宽度自适应
  if($width==0 && $height!=0){
   if($src_height>$height){
    $width = intval($src_width*$height/$src_height);

    if ($this->type == 'gif') {
     $this->_resizeGif($width, $height);
    }else{
     $this->image->thumbnailImage ( $width, $height, true );
    }
   }
   return;
  }

  //缩放的后的尺寸
  $crop_w = $width;
  $crop_h = $height;

  //缩放后裁剪的位置
  $crop_x = 0;
  $crop_y = 0;

  if(($src_width/$src_height) < ($width/$height)){
   //宽高比例小于目标宽高比例  宽度等比例放大      按目标高度从头部截取
   $crop_h = intval($src_height*$width/$src_width);
   //从顶部裁剪  不用计算 $crop_y
  }else{
   //宽高比例大于目标宽高比例   高度等比例放大      按目标宽度居中裁剪
   $crop_w = intval($src_width*$height/$src_height);
   $crop_x = intval(($crop_w-$width)/2);
  }

  if ($this->type == 'gif') {
   $this->_resizeGif($crop_w, $crop_h, true, $width, $height,$crop_x, $crop_y);
  } else {
   $this->image->thumbnailImage ( $crop_w, $crop_h, true );
   $this->image->cropImage($width, $height,$crop_x, $crop_y);
  }
 }

 /**
* Processing gif images requires processing each frame
* @param unknown $t_w Zoom width
* @param unknown $t_h Zoom height
* @param string $isCrop Whether to crop
* @param number $c_w Cropping width
* @param number $c_h Cropping height
* @param number $c_x Cropping coordinates x
* @param number $c_y Cropping coordinates y
*/
 private function _resizeGif($t_w, $t_h, $isCrop=false, $c_w=0, $c_h=0, $c_x=0, $c_y=0){
  $dest = new Imagick();
  $color_transparent = new ImagickPixel("transparent"); //透明色
  foreach($this->image as $img){
   $page = $img->getImagePage();
   $tmp = new Imagick();
   $tmp->newImage($page['width'], $page['height'], $color_transparent, 'gif');
   $tmp->compositeImage($img, Imagick::COMPOSITE_OVER, $page['x'], $page['y']);

   $tmp->thumbnailImage ( $t_w, $t_h, true );
   if($isCrop){
    $tmp->cropImage($c_w, $c_h, $c_x, $c_y);
   }

   $dest->addImage($tmp);
   $dest->setImagePage($tmp->getImageWidth(), $tmp->getImageHeight(), 0, 0);
   $dest->setImageDelay($img->getImageDelay());
   $dest->setImageDispose($img->getImageDispose());

  }
  $this->image->destroy ();
  $this->image = $dest;
 }

 
 /**
* Change the image size
* $fit: adapt to the size method
* 'force': force the image to $width Scale the image within width X $height. The output scaled image size is not exactly equal to $width Fill color,
* When using this parameter, you can set the background fill color $bg_color = array(255,255,255) (red, green, blue, transparency)
* Transparency (0 opaque-127 fully transparent)) Others: Smart mode Can scale the image and load the middle part of the image $width When , the corresponding relationship between the letters and the image in the specified position is output as follows:
* north_west north north_east
* west center east
* south_west south south_east
*/
 public function resize_to($width = 100, $height = 100, $fit = 'center', $fill_color = array(255,255,255,0)) {
  switch ($fit) {
   case 'force' :
    if ($this->type == 'gif') {
     $image = $this->image;
     $canvas = new Imagick ();

     $images = $image->coalesceImages ();
     foreach ( $images as $frame ) {
      $img = new Imagick ();
      $img->readImageBlob ( $frame );
      $img->thumbnailImage ( $width, $height, false );

      $canvas->addImage ( $img );
      $canvas->setImageDelay ( $img->getImageDelay () );
     }
     $image->destroy ();
     $this->image = $canvas;
    } else {
     $this->image->thumbnailImage ( $width, $height, false );
    }
    break;
   case 'scale' :
    if ($this->type == 'gif') {
     $image = $this->image;
     $images = $image->coalesceImages ();
     $canvas = new Imagick ();
     foreach ( $images as $frame ) {
      $img = new Imagick ();
      $img->readImageBlob ( $frame );
      $img->thumbnailImage ( $width, $height, true );

      $canvas->addImage ( $img );
      $canvas->setImageDelay ( $img->getImageDelay () );
     }
     $image->destroy ();
     $this->image = $canvas;
    } else {
     $this->image->thumbnailImage ( $width, $height, true );
    }
    break;
   case 'scale_fill' :
    $size = $this->image->getImagePage ();
    $src_width = $size ['width'];
    $src_height = $size ['height'];

    $x = 0;
    $y = 0;

    $dst_width = $width;
    $dst_height = $height;

    if ($src_width * $height > $src_height * $width) {
     $dst_height = intval ( $width * $src_height / $src_width );
     $y = intval ( ($height - $dst_height) / 2 );
    } else {
     $dst_width = intval ( $height * $src_width / $src_height );
     $x = intval ( ($width - $dst_width) / 2 );
    }

    $image = $this->image;
    $canvas = new Imagick ();

    $color = 'rgba(' . $fill_color [0] . ',' . $fill_color [1] . ',' . $fill_color [2] . ',' . $fill_color [3] . ')';
    if ($this->type == 'gif') {
     $images = $image->coalesceImages ();
     foreach ( $images as $frame ) {
      $frame->thumbnailImage ( $width, $height, true );

      $draw = new ImagickDraw ();
      $draw->composite ( $frame->getImageCompose (), $x, $y, $dst_width, $dst_height, $frame );

      $img = new Imagick ();
      $img->newImage ( $width, $height, $color, 'gif' );
      $img->drawImage ( $draw );

      $canvas->addImage ( $img );
      $canvas->setImageDelay ( $img->getImageDelay () );
      $canvas->setImagePage ( $width, $height, 0, 0 );
     }
    } else {
     $image->thumbnailImage ( $width, $height, true );

     $draw = new ImagickDraw ();
     $draw->composite ( $image->getImageCompose (), $x, $y, $dst_width, $dst_height, $image );

     $canvas->newImage ( $width, $height, $color, $this->get_type () );
     $canvas->drawImage ( $draw );
     $canvas->setImagePage ( $width, $height, 0, 0 );
    }
    $image->destroy ();
    $this->image = $canvas;
    break;
   default :
    $size = $this->image->getImagePage ();
    $src_width = $size ['width'];
    $src_height = $size ['height'];

    $crop_x = 0;
    $crop_y = 0;

    $crop_w = $src_width;
    $crop_h = $src_height;

    if ($src_width * $height > $src_height * $width) {
     $crop_w = intval ( $src_height * $width / $height );
    } else {
     $crop_h = intval ( $src_width * $height / $width );
    }

    switch ($fit) {
     case 'north_west' :
      $crop_x = 0;
      $crop_y = 0;
      break;
     case 'north' :
      $crop_x = intval ( ($src_width - $crop_w) / 2 );
      $crop_y = 0;
      break;
     case 'north_east' :
      $crop_x = $src_width - $crop_w;
      $crop_y = 0;
      break;
     case 'west' :
      $crop_x = 0;
      $crop_y = intval ( ($src_height - $crop_h) / 2 );
      break;
     case 'center' :
      $crop_x = intval ( ($src_width - $crop_w) / 2 );
      $crop_y = intval ( ($src_height - $crop_h) / 2 );
      break;
     case 'east' :
      $crop_x = $src_width - $crop_w;
      $crop_y = intval ( ($src_height - $crop_h) / 2 );
      break;
     case 'south_west' :
      $crop_x = 0;
      $crop_y = $src_height - $crop_h;
      break;
     case 'south' :
      $crop_x = intval ( ($src_width - $crop_w) / 2 );
      $crop_y = $src_height - $crop_h;
      break;
     case 'south_east' :
      $crop_x = $src_width - $crop_w;
      $crop_y = $src_height - $crop_h;
      break;
     default :
      $crop_x = intval ( ($src_width - $crop_w) / 2 );
      $crop_y = intval ( ($src_height - $crop_h) / 2 );
    }

    $image = $this->image;
    $canvas = new Imagick ();

    if ($this->type == 'gif') {
     $images = $image->coalesceImages ();
     foreach ( $images as $frame ) {
      $img = new Imagick ();
      $img->readImageBlob ( $frame );
      $img->cropImage ( $crop_w, $crop_h, $crop_x, $crop_y );
      $img->thumbnailImage ( $width, $height, true );

      $canvas->addImage ( $img );
      $canvas->setImageDelay ( $img->getImageDelay () );
      $canvas->setImagePage ( $width, $height, 0, 0 );
     }
    } else {
     $image->cropImage ( $crop_w, $crop_h, $crop_x, $crop_y );
     $image->thumbnailImage ( $width, $height, true );
     $canvas->addImage ( $image );
     $canvas->setImagePage ( $width, $height, 0, 0 );
    }
    $image->destroy ();
    $this->image = $canvas;
  }
 }

 // 添加水印图片
 public function add_watermark($path, $x = 0, $y = 0) {
  $watermark = new Imagick ( $path );
  $draw = new ImagickDraw ();
  $draw->composite ( $watermark->getImageCompose (), $x, $y, $watermark->getImageWidth (), $watermark->getimageheight (), $watermark );

  if ($this->type == 'gif') {
   $image = $this->image;
   $canvas = new Imagick ();
   $images = $image->coalesceImages ();
   foreach ( $image as $frame ) {
    $img = new Imagick ();
    $img->readImageBlob ( $frame );
    $img->drawImage ( $draw );

    $canvas->addImage ( $img );
    $canvas->setImageDelay ( $img->getImageDelay () );
   }
   $image->destroy ();
   $this->image = $canvas;
  } else {
   $this->image->drawImage ( $draw );
  }
 }

 // 添加水印文字
 public function add_text($text, $x = 0, $y = 0, $angle = 0, $style = array()) {
  $draw = new ImagickDraw ();
  if (isset ( $style ['font'] ))
   $draw->setFont ( $style ['font'] );
  if (isset ( $style ['font_size'] ))
   $draw->setFontSize ( $style ['font_size'] );
  if (isset ( $style ['fill_color'] ))
   $draw->setFillColor ( $style ['fill_color'] );
  if (isset ( $style ['under_color'] ))
   $draw->setTextUnderColor ( $style ['under_color'] );

  if ($this->type == 'gif') {
   foreach ( $this->image as $frame ) {
    $frame->annotateImage ( $draw, $x, $y, $angle, $text );
   }
  } else {
   $this->image->annotateImage ( $draw, $x, $y, $angle, $text );
  }
 }

 // 保存到指定路径
 public function save_to($path) {
  //压缩图片质量
  $this->image->setImageFormat('JPEG');
  $this->image->setImageCompression(Imagick::COMPRESSION_JPEG);
  $a = $this->image->getImageCompressionQuality() * 0.60;
  if ($a == 0) {
   $a = 60;
  }
  $this->image->setImageCompressionQuality($a);
  $this->image->stripImage();

  if ($this->type == 'gif') {
   $this->image->writeImages ( $path, true );
  } else {
   $this->image->writeImage ( $path );
  }
 }

 // 输出图像
 public function output($header = true) {
  if ($header)
   header ( 'Content-type: ' . $this->type );
  echo $this->image->getImagesBlob ();
 }
 public function get_width() {
  $size = $this->image->getImagePage ();
  return $size ['width'];
 }
 public function get_height() {
  $size = $this->image->getImagePage ();
  return $size ['height'];
 }

 // 设置图像类型， 默认与源类型一致
 public function set_type($type = 'png') {
  $this->type = $type;
  $this->image->setImageFormat ( $type );
 }

 // 获取源图像类型
 public function get_type() {
  return $this->type;
 }

 public function get_file_size(){
  if($this->image){
   return 0;//$this->image->getImageLength(); getImageLength not find
  }else{
   return 0;
  }
 }

 public function get_file_type(){
  if($this->image){
   return $this->image->getimagemimetype();
  }else{
   return 0;
  }
 }

 public function get_sha1(){
  if($this->image){
   return sha1($this->image->__tostring());
  }else{
   return '';
  }
 }

 // 当前对象是否为图片
 public function is_image() {
  if ($this->image)
   return true;
  else
   return false;
 }

 /*
  * 添加一个边框 $width: 左右边框宽度 $height: 上下边框宽度 $color: 颜色: RGB 颜色 'rgb(255,0,0)' 或 16进制颜色 '#FF0000' 或颜色单词 'white'/'red'...
  */
 public function border($width, $height, $color = 'rgb(220, 220, 220)') {
  $color = new ImagickPixel ();
  $color->setColor ( $color );
  $this->image->borderImage ( $color, $width, $height );
 }
 public function blur($radius, $sigma) {
  $this->image->blurImage ( $radius, $sigma );
 } // 模糊
 public function gaussian_blur($radius, $sigma) {
  $this->image->gaussianBlurImage ( $radius, $sigma );
 } // 高斯模糊
 public function motion_blur($radius, $sigma, $angle) {
  $this->image->motionBlurImage ( $radius, $sigma, $angle );
 }// Motion blur
public function radial_blur($radius) {
$this->image->radialBlurImage ( $radius );
} // Radial blur
public function add_noise($ type = null) {
$this->image->addNoiseImage ( $type == null ? imagick::NOISE_IMPULSE : $type );
} // Add noise
public function level($ black_point, $gamma, $white_point) {
$this->image->levelImage ( $black_point, $gamma, $white_point );
} // Adjust the color level
public function modulate($ brightness, $saturation, $hue) {
$this->image->modulateImage ( $brightness, $saturation, $hue );
} // Adjust brightness, saturation, hue
public function charcoal($radius, $sigma) {
$this->image->charcoalImage ( $radius, $sigma );
} // Sketch
public function oil_paint($radius) {
$this->image->oilPaintImage ( $radius );
} // Oil painting effect
public function flop() {
$this->image->flopImage ();
} // Flip horizontally
public function flip() {
$this->image->flipImage ();
} // Flip vertically
}