git.roojs.org Git - pear/blob - FpdfAlt/ImageAlpha.php

   1  <?php
   2 /*******************************************************************************
   3 * Software: PDF_ImageAlpha
   4 * Version:  1.4
   5 * Date:     2009-12-28
   6 * Author:   Valentin Schmidt
   7 *
   8 * Requirements: FPDF 1.6
   9 *
  10 * This script allows to use images (PNGs or JPGs) with alpha-channels.
  11 * The alpha-channel can be either supplied as separate 8-bit PNG ("mask"),
  12 * or, for PNGs, also an internal alpha-channel can be used.
  13 * For the latter the GD 2.x extension is required.
  14 *******************************************************************************/
  15
  16 require_once 'Fpdf.php';
  17
  18 class Fpdf_ImageAlpha extends Fpdf{
  19
  20 //Private properties
  21 var $tmpFiles = array();
  22
  23 /*******************************************************************************
  24 *                                                                              *
  25 *                               Public methods                                 *
  26 *                                                                              *
  27 *******************************************************************************/
  28 function Image($file,$x,$y,$w=0,$h=0,$type='',$link='', $isMask=false, $maskImg=0)
  29 {
  30     //Put an image on the page
  31     if(!isset($this->images[$file]))
  32     {
  33         //First use of image, get info
  34         if($type=='')
  35         {
  36             $pos=strrpos($file,'.');
  37             if(!$pos)
  38                 $this->Error('Image file has no extension and no type was specified: '.$file);
  39             $type=substr($file,$pos+1);
  40         }
  41         $type=strtolower($type);
  42         //$mqr=get_magic_quotes_runtime();
  43         //@set_magic_quotes_runtime(0);
  44         if($type=='jpg' || $type=='jpeg')
  45             $info=$this->_parsejpg($file);
  46         elseif($type=='png'){
  47             $info=$this->_parsepng($file);
  48             if ($info=='alpha') return $this->ImagePngWithAlpha($file,$x,$y,$w,$h,$link);
  49         }
  50         else
  51         {
  52             //Allow for additional formats
  53             $mtd='_parse'.$type;
  54             if(!method_exists($this,$mtd))
  55                 $this->Error('Unsupported image type: '.$type);
  56             $info=$this->$mtd($file);
  57         }
  58         //set_magic_quotes_runtime($mqr);
  59
  60         if ($isMask){
  61       $info['cs']="DeviceGray"; // try to force grayscale (instead of indexed)
  62     }
  63         $info['i']=count($this->images)+1;
  64         if ($maskImg>0) $info['masked'] = $maskImg;###
  65         $this->images[$file]=$info;
  66     }
  67     else
  68         $info=$this->images[$file];
  69     //Automatic width and height calculation if needed
  70     if($w==0 && $h==0)
  71     {
  72         //Put image at 72 dpi
  73         $w=$info['w']/$this->k;
  74         $h=$info['h']/$this->k;
  75     }
  76     if($w==0)
  77         $w=$h*$info['w']/$info['h'];
  78     if($h==0)
  79         $h=$w*$info['h']/$info['w'];
  80
  81     // embed hidden, ouside the canvas
  82     if ((float)FPDF_VERSION>=1.7){
  83         if ($isMask) $x = ($this->CurOrientation=='P'?$this->CurPageSize[0]:$this->CurPageSize[1]) + 10;
  84     }else{
  85         if ($isMask) $x = ($this->CurOrientation=='P'?$this->CurPageFormat[0]:$this->CurPageFormat[1]) + 10;
  86     }
  87
  88     $this->_out(sprintf('q %.2f 0 0 %.2f %.2f %.2f cm /I%d Do Q',$w*$this->k,$h*$this->k,$x*$this->k,($this->h-($y+$h))*$this->k,$info['i']));
  89     if($link)
  90         $this->Link($x,$y,$w,$h,$link);
  91
  92     return $info['i'];
  93 }
  94
  95 // needs GD 2.x extension
  96 // pixel-wise operation, not very fast
  97 function ImagePngWithAlpha($file,$x,$y,$w=0,$h=0,$link='')
  98 {
  99     $tmp_alpha = tempnam('.', 'mska');
 100     $this->tmpFiles[] = $tmp_alpha;
 101     $tmp_plain = tempnam('.', 'mskp');
 102     $this->tmpFiles[] = $tmp_plain;
 103
 104     list($wpx, $hpx) = getimagesize($file);
 105     $img = imagecreatefrompng($file);
 106     $alpha_img = imagecreate( $wpx, $hpx );
 107
 108     // generate gray scale pallete
 109     for($c=0;$c<256;$c++) ImageColorAllocate($alpha_img, $c, $c, $c);
 110
 111     // extract alpha channel
 112     $xpx=0;
 113     while ($xpx<$wpx){
 114         $ypx = 0;
 115         while ($ypx<$hpx){
 116             $color_index = imagecolorat($img, $xpx, $ypx);
 117             $alpha = 255-($color_index>>24)*255/127; // GD alpha component: 7 bit only, 0..127!
 118             imagesetpixel($alpha_img, $xpx, $ypx, $alpha);
 119         ++$ypx;
 120         }
 121         ++$xpx;
 122     }
 123
 124     imagepng($alpha_img, $tmp_alpha);
 125     imagedestroy($alpha_img);
 126
 127     // extract image without alpha channel
 128     $plain_img = imagecreatetruecolor ( $wpx, $hpx );
 129     imagecopy ($plain_img, $img, 0, 0, 0, 0, $wpx, $hpx );
 130     imagepng($plain_img, $tmp_plain);
 131     imagedestroy($plain_img);
 132
 133     //first embed mask image (w, h, x, will be ignored)
 134     $maskImg = $this->Image($tmp_alpha, 0,0,0,0, 'PNG', '', true);
 135
 136     //embed image, masked with previously embedded mask
 137     $this->Image($tmp_plain,$x,$y,$w,$h,'PNG',$link, false, $maskImg);
 138 }
 139
 140 function Close()
 141 {
 142     parent::Close();
 143     // clean up tmp files
 144     foreach($this->tmpFiles as $tmp) @unlink($tmp);
 145 }
 146
 147 /*******************************************************************************
 148 *                                                                              *
 149 *                               Private methods                                *
 150 *                                                                              *
 151 *******************************************************************************/
 152 function _putimages()
 153 {
 154     $filter=($this->compress) ? '/Filter /FlateDecode ' : '';
 155     reset($this->images);
 156     while(list($file,$info)=each($this->images))
 157     {
 158         $this->_newobj();
 159         $this->images[$file]['n']=$this->n;
 160         $this->_out('<</Type /XObject');
 161         $this->_out('/Subtype /Image');
 162         $this->_out('/Width '.$info['w']);
 163         $this->_out('/Height '.$info['h']);
 164
 165         if (isset($info["masked"])) $this->_out('/SMask '.($this->n-1).' 0 R'); ###
 166
 167         if($info['cs']=='Indexed')
 168             $this->_out('/ColorSpace [/Indexed /DeviceRGB '.(strlen($info['pal'])/3-1).' '.($this->n+1).' 0 R]');
 169         else
 170         {
 171             $this->_out('/ColorSpace /'.$info['cs']);
 172             if($info['cs']=='DeviceCMYK')
 173                 $this->_out('/Decode [1 0 1 0 1 0 1 0]');
 174         }
 175         $this->_out('/BitsPerComponent '.$info['bpc']);
 176         if(isset($info['f']))
 177             $this->_out('/Filter /'.$info['f']);
 178         if(isset($info['parms']))
 179             $this->_out($info['parms']);
 180         if(isset($info['trns']) && is_array($info['trns']))
 181         {
 182             $trns='';
 183             for($i=0;$i<count($info['trns']);$i++)
 184                 $trns.=$info['trns'][$i].' '.$info['trns'][$i].' ';
 185             $this->_out('/Mask ['.$trns.']');
 186         }
 187         $this->_out('/Length '.strlen($info['data']).'>>');
 188         $this->_putstream($info['data']);
 189         unset($this->images[$file]['data']);
 190         $this->_out('endobj');
 191         //Palette
 192         if($info['cs']=='Indexed')
 193         {
 194             $this->_newobj();
 195             $pal=($this->compress) ? gzcompress($info['pal']) : $info['pal'];
 196             $this->_out('<<'.$filter.'/Length '.strlen($pal).'>>');
 197             $this->_putstream($pal);
 198             $this->_out('endobj');
 199         }
 200     }
 201 }
 202
 203 // this method overwriing the original version is only needed to make the Image method support PNGs with alpha channels.
 204 // if you only use the ImagePngWithAlpha method for such PNGs, you can remove it from this script.
 205 function _parsepng($file)
 206 {
 207     //Extract info from a PNG file
 208     $f=fopen($file,'rb');
 209     if(!$f)
 210         $this->Error('Can\'t open image file: '.$file);
 211     //Check signature
 212     if(fread($f,8)!=chr(137).'PNG'.chr(13).chr(10).chr(26).chr(10))
 213         $this->Error('Not a PNG file: '.$file);
 214     //Read header chunk
 215     fread($f,4);
 216     if(fread($f,4)!='IHDR')
 217         $this->Error('Incorrect PNG file: '.$file);
 218     $w=$this->_readint($f);
 219     $h=$this->_readint($f);
 220     $bpc=ord(fread($f,1));
 221     if($bpc>8)
 222         $this->Error('16-bit depth not supported: '.$file);
 223     $ct=ord(fread($f,1));
 224     if($ct==0)
 225         $colspace='DeviceGray';
 226     elseif($ct==2)
 227         $colspace='DeviceRGB';
 228     elseif($ct==3)
 229         $colspace='Indexed';
 230     else {
 231         fclose($f);      // the only changes are
 232         return 'alpha';  // made in those 2 lines
 233     }
 234     if(ord(fread($f,1))!=0)
 235         $this->Error('Unknown compression method: '.$file);
 236     if(ord(fread($f,1))!=0)
 237         $this->Error('Unknown filter method: '.$file);
 238     if(ord(fread($f,1))!=0)
 239         $this->Error('Interlacing not supported: '.$file);
 240     fread($f,4);
 241     $parms='/DecodeParms <</Predictor 15 /Colors '.($ct==2 ? 3 : 1).' /BitsPerComponent '.$bpc.' /Columns '.$w.'>>';
 242     //Scan chunks looking for palette, transparency and image data
 243     $pal='';
 244     $trns='';
 245     $data='';
 246     do
 247     {
 248         $n=$this->_readint($f);
 249         $type=fread($f,4);
 250         if($type=='PLTE')
 251         {
 252             //Read palette
 253             $pal=fread($f,$n);
 254             fread($f,4);
 255         }
 256         elseif($type=='tRNS')
 257         {
 258             //Read transparency info
 259             $t=fread($f,$n);
 260             if($ct==0)
 261                 $trns=array(ord(substr($t,1,1)));
 262             elseif($ct==2)
 263                 $trns=array(ord(substr($t,1,1)),ord(substr($t,3,1)),ord(substr($t,5,1)));
 264             else
 265             {
 266                 $pos=strpos($t,chr(0));
 267                 if($pos!==false)
 268                     $trns=array($pos);
 269             }
 270             fread($f,4);
 271         }
 272         elseif($type=='IDAT')
 273         {
 274             //Read image data block
 275             $data.=fread($f,$n);
 276             fread($f,4);
 277         }
 278         elseif($type=='IEND')
 279             break;
 280         else
 281             fread($f,$n+4);
 282     }
 283     while($n);
 284     if($colspace=='Indexed' && empty($pal))
 285         $this->Error('Missing palette in '.$file);
 286     fclose($f);
 287     return array('w'=>$w,'h'=>$h,'cs'=>$colspace,'bpc'=>$bpc,'f'=>'FlateDecode','parms'=>$parms,'pal'=>$pal,'trns'=>$trns,'data'=>$data);
 288 }
 289
 290 function _readstream($f, $n)
 291 {
 292         // Read n bytes from stream
 293         $res = '';
 294         while($n>0 && !feof($f))
 295         {
 296                 $s = fread($f,$n);
 297                 if($s===false)
 298                         $this->Error('Error while reading stream');
 299                 $n -= strlen($s);
 300                 $res .= $s;
 301         }
 302         if($n>0)
 303                 $this->Error('Unexpected end of stream');
 304         return $res;
 305 }
 306
 307 function _readint($f)
 308 {
 309         // Read a 4-byte integer from stream
 310         $a = unpack('Ni',$this->_readstream($f,4));
 311         return $a['i'];
 312 }
 313 }
 314