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   1  <?php // $Id: imageapi_gd.module,v 1.13.2.7 2009/04/17 00:15:21 drewish Exp $
   2  
   3  /**
   4   * @file
   5   * GD2 toolkit functions
   6   */
   7  
   8  /**
   9   * Implementation of hook_imageapi_toolkit().
  10   *
  11   * this hook only gets called to see is a module implements the imageapi hooks...
  12   */
  13  function imageapi_gd_imageapi_toolkit() {
  14  }
  15  
  16  
  17  /**
  18   * Settings form for the toolkit.
  19   */
  20  function imageapi_gd_settings_form() {
  21    $form['imageapi_jpeg_quality'] = array(
  22      '#type' => 'textfield',
  23      '#title' => t('JPEG quality'),
  24      '#description' => t('Define the image quality for JPEG manipulations. Ranges from 0 to 100. Higher values mean better image quality, but bigger files.'),
  25      '#size' => 10,
  26      '#maxlength' => 3,
  27      '#default_value' => variable_get('imageapi_jpeg_quality', 75),
  28      '#field_suffix' => '%',
  29    );
  30    return system_settings_form($form);
  31  }
  32  
  33  /**
  34   * Open an image file.
  35   *
  36   * @param $image
  37   *   An image object. The $image->resource value will populated by this call.
  38   * @return
  39   *   TRUE or FALSE, based on success.
  40   */
  41  function imageapi_gd_image_open($image) {
  42    $extension = str_replace('jpg', 'jpeg', $image->info['extension']);
  43    $function = 'imagecreatefrom'. $extension;
  44    return (function_exists($function) && $image->resource = $function($image->source));
  45  }
  46  
  47  /**
  48   * Save an image file to a destination.
  49   * 
  50   * @param $image
  51   *   An image object.
  52   * @param $destination
  53   *   A string file path where the image should be saved.
  54   * @param $extension
  55   *   A string containing one of the following extensions: gif, jpg, jpeg, png.
  56   * @return
  57   *   TRUE or FALSE, based on success.
  58   */
  59  function imageapi_gd_image_close($image, $destination) {
  60    $extension = str_replace('jpg', 'jpeg', $image->info['extension']);
  61    $function = 'image'. $extension;
  62    if (!function_exists($function)) {
  63      return FALSE;
  64    }
  65    if ($extension == 'jpeg') {
  66      return $function($image->resource, $destination, variable_get('imageapi_jpeg_quality', 75));
  67    }
  68    else {
  69      // Always save PNG images with full transparency.
  70      if ($extension == 'png') {
  71        imagealphablending($image->resource, FALSE);
  72        imagesavealpha($image->resource, TRUE);
  73      }
  74      return $function($image->resource, $destination);
  75    }
  76  }
  77  
  78  /**
  79   * Crop an image using the GD toolkit.
  80   *
  81   * @param $image
  82   *   An image object. The $image->resource, $image->info['width'], and
  83   *   $image->info['height'] values will be modified by this call.
  84   * @param $x
  85   *   The starting x offset at which to start the crop, in pixels.
  86   * @param $y
  87   *   The starting y offset at which to start the crop, in pixels.
  88   * @param $width
  89   *   The width of the cropped area, in pixels.
  90   * @param $height
  91   *   The height of the cropped area, in pixels.
  92   * @return
  93   *   TRUE or FALSE, based on success.
  94   */
  95  function imageapi_gd_image_crop(&$image, $x, $y, $width, $height) {
  96    $res = imageapi_gd_create_tmp($image, $width, $height);
  97  
  98    if (!imagecopyresampled($res, $image->resource, 0, 0, $x, $y, $width, $height, $width, $height)) {
  99      return FALSE;
 100    }
 101  
 102    // Destroy the original image and return the modified image.
 103    imagedestroy($image->resource);
 104    $image->resource = $res;
 105    $image->info['width'] = $width;
 106    $image->info['height'] = $height;
 107    return TRUE;
 108  }
 109  
 110  /**
 111   * Scale an image to the specified size using GD.
 112   *
 113   * @param $image
 114   *   An image object. The $image->resource, $image->info['width'], and
 115   *   $image->info['height'] values will be modified by this call.
 116   * @param $width
 117   *   The new width of the resized image, in pixels.
 118   * @param $height
 119   *   The new height of the resized image, in pixels.
 120   * @return
 121   *   TRUE or FALSE, based on success.
 122   */
 123  function imageapi_gd_image_resize(&$image, $width, $height) {
 124    $res = imageapi_gd_create_tmp($image, $width, $height);
 125  
 126    if (!imagecopyresampled($res, $image->resource, 0, 0, 0, 0, $width, $height, $image->info['width'], $image->info['height'])) {
 127      return FALSE;
 128    }
 129  
 130    imagedestroy($image->resource);
 131    // Update image object.
 132    $image->resource = $res;
 133    $image->info['width'] = $width;
 134    $image->info['height'] = $height;
 135    return TRUE;
 136  }
 137  
 138  /**
 139   * Rotate an image the given number of degrees.
 140   *
 141   * @param $image
 142   *   An image object. The $image->resource, $image->info['width'], and
 143   *   $image->info['height'] values will be modified by this call.
 144   * @param $degrees
 145   *   The number of (clockwise) degrees to rotate the image.
 146   * @param $background
 147   *   An hexadecimal integer specifying the background color to use for the
 148   *   uncovered area of the image after the rotation. E.g. 0x000000 for black,
 149   *   0xff00ff for magenta, and 0xffffff for white. For images that support
 150   *   transparency, this will default to transparent. Otherwise it will
 151   *   be white.
 152   * @return
 153   *   TRUE or FALSE, based on success.
 154   */
 155   function imageapi_gd_image_rotate(&$image, $degrees, $background) {
 156    // PHP installations using non-bundled GD do not have imagerotate.
 157    if (!function_exists('imagerotate')) {
 158      require_once drupal_get_path('module', 'imageapi_gd') .'/imagerotate.inc';
 159    }
 160  
 161    $width = $image->info['width'];
 162    $height = $image->info['height'];
 163  
 164    // Convert the hexadecimal background value to a color index value.
 165    if (isset($background)) {
 166      $rgb = array();
 167      for ($i = 16; $i >= 0; $i -= 8) {
 168        $rgb[] = (($background >> $i) & 0xFF);
 169      }
 170      $background = imagecolorallocatealpha($image->resource, $rgb[0], $rgb[1], $rgb[2], 0);
 171    }
 172    // Set the background color as transparent if $background is NULL.
 173    else {
 174      // Get the current transparent color.
 175      $background = imagecolortransparent($image->resource);
 176  
 177      // If no transparent colors, use white.
 178      if ($background == 0) {
 179        $background = imagecolorallocatealpha($image->resource, 255, 255, 255, 0);
 180      }
 181    }
 182  
 183    // Images are assigned a new color pallete when rotating, removing any
 184    // transparency flags. For GIF images, keep a record of the transparent color.
 185    if ($image->info['extension'] == 'gif') {
 186      $transparent_index = imagecolortransparent($image->resource);
 187      if ($transparent_index != 0) {
 188        $transparent_gif_color = imagecolorsforindex($image->resource, $transparent_index);
 189      }
 190    }
 191  
 192    $image->resource = imagerotate($image->resource, 360 - $degrees, $background);
 193  
 194    // GIFs need to reassign the transparent color after performing the rotate.
 195    if (isset($transparent_gif_color)) {
 196      $background = imagecolorexactalpha($image->resource, $transparent_gif_color['red'], $transparent_gif_color['green'], $transparent_gif_color['blue'], $transparent_gif_color['alpha']);
 197      imagecolortransparent($image->resource, $background);
 198    }
 199  
 200    $image->info['width'] = imagesx($image->resource);
 201    $image->info['height'] = imagesy($image->resource);
 202    return TRUE;
 203  } 
 204  
 205  function imageapi_gd_image_sharpen(&$image, $radius, $sigma, $amount, $threshold) {
 206    $threshold = round($threshold * 255);
 207    $image->resource = imageapi_gd_unsharp_mask($image->resource, $radius, $sigma, $amount, $threshold);
 208    return TRUE;
 209  }
 210  
 211  /**
 212   * Convert an image resource to grayscale.
 213   *
 214   * Note that transparent GIFs loose transparency when desaturated.
 215   *
 216   * @param $image
 217   *   An image object. The $image->resource value will be modified by this call.
 218   * @return
 219   *   TRUE or FALSE, based on success.
 220   */
 221  function imageapi_gd_image_desaturate(&$image) {
 222    // PHP installations using non-bundled GD do not have imagefilter.
 223    if (!function_exists('imagefilter')) {
 224      require_once drupal_get_path('module', 'imageapi_gd') .'/imagefilter.inc';
 225    }
 226  
 227    return imagefilter($image->resource, IMG_FILTER_GRAYSCALE);
 228  }
 229  
 230  /**
 231   * Create a truecolor image preserving transparency from a provided image.
 232   *
 233   * @param $image
 234   *   An image object.
 235   * @param $width
 236   *   The new width of the new image, in pixels.
 237   * @param $height
 238   *   The new height of the new image, in pixels.
 239   * @return
 240   *   A GD image handle.
 241   */
 242  function imageapi_gd_create_tmp($image, $width, $height) {
 243    $res = imagecreatetruecolor($width, $height);
 244  
 245    if ($image->info['extension'] == 'gif') {
 246      // Grab transparent color index from image resource.
 247      $transparent = imagecolortransparent($image->resource);
 248  
 249      if ($transparent >= 0) {
 250        // The original must have a transparent color, allocate to the new image.
 251        $transparent_color = imagecolorsforindex($image->resource, $transparent);
 252        $transparent = imagecolorallocate($res, $transparent_color['red'], $transparent_color['green'], $transparent_color['blue']);
 253  
 254        // Flood with our new transparent color.
 255        imagefill($res, 0, 0, $transparent);
 256        imagecolortransparent($res, $transparent);
 257      }
 258    }
 259    elseif ($image->info['extension'] == 'png') {
 260      imagealphablending($res, FALSE);
 261      $transparency = imagecolorallocatealpha($res, 0, 0, 0, 127);
 262      imagefill($res, 0, 0, $transparency);
 263      imagealphablending($res, TRUE);
 264      imagesavealpha($res, TRUE);
 265    }
 266    else {
 267      imagefill($res, 0, 0, imagecolorallocate($res, 255, 255, 255));
 268    }
 269  
 270    return $res;
 271  }
 272  
 273  /**
 274   * $sigma is currently unused for _gd_sharp_mask due to 3x3 convolution matrix limit.
 275   * we should explore properly implementing sigma.
 276   */
 277  function imageapi_gd_unsharp_mask($img, $radius, $sigma, $amount, $threshold)    {
 278  
 279    ////////////////////////////////////////////////////////////// 
 280    ////   
 281    ////                  Unsharp Mask for PHP - version 2.1.1   
 282    ////   
 283    ////    Unsharp mask algorithm by Torstein H�nsi 2003-07.   
 284    ////             thoensi_at_netcom_dot_no.   
 285    ////               Please leave this notice.   
 286    ////   
 287    //////////////////////////////////////////////////////////////
 288    
 289    // http://vikjavev.no/computing/ump.php
 290  
 291    // $img is an image that is already created within php using
 292    // imgcreatetruecolor. No url! $img must be a truecolor image.
 293  
 294    // Attempt to calibrate the parameters to Photoshop:
 295    if ($amount > 500) $amount = 500;
 296    $amount = $amount * 0.016;
 297    if ($radius > 50) $radius = 50;
 298    $radius = $radius * 2;
 299    if ($threshold > 255) $threshold = 255;
 300  
 301    $radius = abs(round($radius)); // Only integers make sense.
 302    if ($radius == 0) {
 303      return $img; imagedestroy($img);
 304      break;
 305    }
 306  
 307    $w = imagesx($img); $h = imagesy($img);
 308    $img_canvas = imagecreatetruecolor($w, $h);
 309    $img_blur = imagecreatetruecolor($w, $h);
 310  
 311    // Gaussian blur matrix:
 312    //                          
 313    //    1    2    1          
 314    //    2    4    2          
 315    //    1    2    1          
 316    //                          
 317    //////////////////////////////////////////////////  
 318  
 319    $matrix = array(
 320      array( 1, 2, 1 ),
 321      array( 2, 4, 2 ),
 322      array( 1, 2, 1 ) 
 323      );
 324  
 325    imagecopy($img_blur, $img, 0, 0, 0, 0, $w, $h);
 326    imageconvolution($img_blur, $matrix, 16, 0);
 327  
 328    if ($threshold > 0) {
 329      // Calculate the difference between the blurred pixels and the original
 330      // and set the pixels
 331      for ($x = 0; $x < $w-1; $x++)    { // each row
 332        for ($y = 0; $y < $h; $y++)    { // each pixel
 333  
 334          $rgb_orig = imagecolorat($img, $x, $y);
 335          $r_orig = (($rgb_orig >> 16) & 0xFF);
 336          $g_orig = (($rgb_orig >> 8) & 0xFF);
 337          $b_orig = ($rgb_orig & 0xFF);
 338  
 339          $rgb_blur = imagecolorat($img_blur, $x, $y);
 340  
 341          $r_blur = (($rgb_blur >> 16) & 0xFF);
 342          $g_blur = (($rgb_blur >> 8) & 0xFF);
 343          $b_blur = ($rgb_blur & 0xFF);
 344  
 345          // When the masked pixels differ less from the original
 346          // than the threshold specifies, they are set to their original value.
 347          $r_new = (abs($r_orig - $r_blur) >= $threshold)
 348            ? max(0, min(255, ($amount * ($r_orig - $r_blur)) + $r_orig))
 349            : $r_orig;
 350          $g_new = (abs($g_orig - $g_blur) >= $threshold)
 351            ? max(0, min(255, ($amount * ($g_orig - $g_blur)) + $g_orig))
 352            : $g_orig;
 353          $b_new = (abs($b_orig - $b_blur) >= $threshold)
 354            ? max(0, min(255, ($amount * ($b_orig - $b_blur)) + $b_orig))
 355            : $b_orig;
 356  
 357          if (($r_orig != $r_new) || ($g_orig != $g_new) || ($b_orig != $b_new)) {
 358            $pix_col = imagecolorallocate($img, $r_new, $g_new, $b_new);
 359            imagesetpixel($img, $x, $y, $pix_col);
 360          }
 361        }
 362      }
 363    }
 364    else{
 365      for ($x = 0; $x < $w; $x++)    { // each row
 366        for ($y = 0; $y < $h; $y++)    { // each pixel
 367          $rgb_orig = imagecolorat($img, $x, $y);
 368          $r_orig = (($rgb_orig >> 16) & 0xFF);
 369          $g_orig = (($rgb_orig >> 8) & 0xFF);
 370          $b_orig = ($rgb_orig & 0xFF);
 371  
 372          $rgb_blur = imagecolorat($img_blur, $x, $y);
 373  
 374          $r_blur = (($rgb_blur >> 16) & 0xFF);
 375          $g_blur = (($rgb_blur >> 8) & 0xFF);
 376          $b_blur = ($rgb_blur & 0xFF);
 377  
 378          $r_new = ($amount * ($r_orig - $r_blur)) + $r_orig;
 379          if ($r_new>255) $r_new=255;
 380          elseif ($r_new<0) $r_new=0;
 381  
 382          $g_new = ($amount * ($g_orig - $g_blur)) + $g_orig;
 383          if ($g_new>255) $g_new=255;
 384          elseif ($g_new<0) $g_new=0;
 385  
 386          $b_new = ($amount * ($b_orig - $b_blur)) + $b_orig;
 387          if ($b_new>255) $b_new=255;
 388          elseif ($b_new<0) $b_new=0;
 389  
 390          $rgb_new = ($r_new << 16) + ($g_new <<8) + $b_new;
 391          imagesetpixel($img, $x, $y, $rgb_new);
 392        }
 393      }
 394    }
 395    imagedestroy($img_canvas);
 396    imagedestroy($img_blur);
 397  
 398    return $img;
 399  }