source: extensions/Histogram/hgram_histogram.class.inc.php @ 26471

<?php
/* -----------------------------------------------------------------------------
  Plugin     : Histogram
  Author     : Grum
    email    : grum@grum.fr
    website  : http://photos.grum.fr
    PWG user : http://forum.piwigo.org/profile.php?id=3706

    << May the Little SpaceFrog be with you ! >>
  ------------------------------------------------------------------------------
  See main.inc.php for release information

  Provided classes :


  --------------------------------------------------------------------------- */

if(!defined('PHPWG_ROOT_PATH')) die('Hacking attempt!');

define('MAX_PIXELS_ANALYZED', 1000000);


class Histogram {
  static public $fileHistogram = Array(
    'pixels' => 0,
    'analyzed' => 0,
    'time' => 0,
    'fileName' => "",
  );

  /**
   * returns histogram values for an image
   *
   *
   * @param String $fileName : the picture's filename
   * @return : -1 if file doesn't exist
   *           -2 if file is not a PNG, a JPEG or a GIF file
   *           -3 if a fatal error occurs
   *            Array of L, R, G, and B values (% for values from 0 to 255)
   */
  static function read($fileName)
  {
    self::$fileHistogram=Array(
      'pixels'   => 0,
      'analyzed' => 0,
      'time' => 0,
      'pps' =>0,
    );

    $returned=array(
      'L' => array(),
      'A' => array(),
      'M' => array(),
      'R' => array(),
      'G' => array(),
      'B' => array()
    );

    for($i=0;$i<256;$i++)
    {
      $returned['L'][$i]=0;
      $returned['A'][$i]=0;
      $returned['M'][$i]=0;
      $returned['R'][$i]=0;
      $returned['G'][$i]=0;
      $returned['B'][$i]=0;
    }

    if(file_exists($fileName))
    {
      $time=microtime(true);

      try
      {
        if(preg_match('/.*\.gif$/i', $fileName))
        {
          $image = imagecreatefromgif($fileName);
        }
        elseif(preg_match('/.*\.(jpg|jpeg)$/i', $fileName))
        {
          $image = imagecreatefromjpeg($fileName);
        }
        elseif(preg_match('/.*\.png$/i', $fileName))
        {
          $image = imagecreatefrompng($fileName);
        }
        else
        {
          return(-2);
        }

        $imageWidth=imagesx($image);
        $imageHeight=imagesy($image);


        $ratio=1;
        $nbPixels=$imageWidth*$imageHeight;
        if($nbPixels>MAX_PIXELS_ANALYZED) $ratio=$nbPixels/MAX_PIXELS_ANALYZED;

        $imageWorkWidth=round($imageWidth/$ratio,0);
        $imageWorkHeight=round($imageHeight/$ratio,0);
        $imageWork=imagecreatetruecolor($imageWorkWidth,$imageWorkHeight);
        imagecopyresampled($imageWork, $image, 0, 0, 0, 0, $imageWorkWidth, $imageWorkHeight, $imageWidth, $imageHeight);
        //imagecopyresized($imageWork, $image, 0, 0, 0, 0, $imageWorkWidth, $imageWorkHeight, $imageWidth, $imageHeight);
        imagedestroy($image);

        $i=0;
        for($px=0;$px<$imageWorkWidth;$px++)
        {
          for($py=0;$py<$imageWorkHeight;$py++)
          {
            $i++;
            $value=imagecolorat($imageWork, $px, $py);

            $rgb=self::IntToRGB($value);
            $l=self::RGBtoL($rgb);
            $a=self::RGBtoA($rgb);
            $m=self::RGBtoM($rgb);

            $returned['L'][$l]++;
            $returned['A'][$a]++;
            $returned['M'][$m]++;
            $returned['R'][$rgb['R']]++;
            $returned['G'][$rgb['G']]++;
            $returned['B'][$rgb['B']]++;

            unset($rgb);
          }
        }

        imagedestroy($imageWork);

        self::$fileHistogram=Array(
          'pixels'   => $imageWorkWidth*$imageWorkHeight,
          'analyzed' => $i,
          'time'     => microtime(true)-$time,
          'pps'      => $i/(microtime(true)-$time),
        );

        ksort($returned['L']);
        ksort($returned['A']);
        ksort($returned['M']);
        ksort($returned['R']);
        ksort($returned['G']);
        ksort($returned['B']);

        foreach($returned as $key => $val)
        {
          $m=max($returned[$key]);
          foreach($returned[$key] as $key2 => $val2)
          {
            $returned[$key][$key2]=round($val2/$m,4);
          }
        }

        return($returned);
      }
      catch (Exception $e)
      {
        //echo "ERROR!<br>".print_r($e, true);
        return(-3);
      }
    }
    else
    {
      return(-1);
    }
  }


  /**
   * build the histogram and save it in an image file
   *
   * @param String $fileName : the histogram filename
   * @param Array $values : array('L', 'R', 'G', 'B') of values
   * @param Array $options : array of options for histogram rendering
   *                'color_bg' : background color
   *                'color_l'  : color for luminance drawing
   *                'color_r'  : color for red drawing
   *                'color_g'  : color for green drawing
   *                'color_b'  : color for blue drawing
   *                'color_ticks'  : color for ticks drawing
   *                'mode_l'   : drawing mode for luminance
   *                'mode_r'   : drawing mode for luminance
   *                'mode_g'   : drawing mode for luminance
   *                'mode_b'   : drawing mode for luminance
   *                  => modes can takes 'line' or 'bar' or 'surface' or 'none' values
   *                'mode_ticks_h' : drawing mode for horizontal ticks
   *                'mode_ticks_v' : drawing mode for vertical ticks
   *                  => can takes 'none' or 'dot' or 'solid'
   *                'histo_width' : histogram width
   *                'histo_height' : histogram height
   */
  static function build($fileName, $values, $options=array())
  {
    $options=self::checkHistoOptions($options);

    $image=imagecreatetruecolor($options['histo_width'], $options['histo_height']);
    $options['color_bg']=self::colorAllocate($image, $options['color_bg']);
    $options['color_v']=self::colorAllocate($image, $options['color_v']);
    $options['color_r']=self::colorAllocate($image, $options['color_r']);
    $options['color_g']=self::colorAllocate($image, $options['color_g']);
    $options['color_b']=self::colorAllocate($image, $options['color_b']);

    imagefilledrectangle($image,0,0,$options['histo_width'], $options['histo_height'], $options['color_bg']);


    $histoList=array('v', 'r', 'g', 'b');


    foreach($histoList as $histo)
    {
      switch($options['mode_'.$histo])
      {
        case 'line':
        case 'surface':
          $points=array(0,$options['histo_height']);
          if($histo=='v')
          {
            $histoKey=$options['histo_method'];
          }
          else
          {
            $histoKey=$histo;
          }

          foreach($values[strtoupper($histoKey)] as $key => $histoValue)
          {
            $points[]=$key * $options['histo_width']/255;
            $points[]=$options['histo_height'] - $histoValue * $options['histo_height'];
          }
          $points[]=$options['histo_width'];
          $points[]=$options['histo_height'];

          if($options['mode_'.$histo]=='line')
          {
            imagepolygon($image,$points, count($points)/2, $options['color_'.$histo]);
          }
          else
          {
            imagefilledpolygon($image,$points, count($points)/2, $options['color_'.$histo]);
          }
          break;
        case 'bar':
          break;
      }
    }

    imagepng($image, $fileName);
    imagedestroy($image);
  }


  /**
   *  Calculate the Luminance value from a RGB value
   *
   * @param Array $RGB : RGB object
   * @return Integer : luminance color
   */
  static public function RGBtoL($RGB)
  {
    return(round($RGB['R']*0.299+$RGB['G']*0.587+$RGB['B']*0.114,0));
  }

  /**
   *  Calculate the average grey value from a RGB value
   *
   * @param Array $RGB : RGB object
   * @return Integer : average grey color
   */
  static public function RGBtoA($RGB)
  {
    return(round(($RGB['R']+$RGB['G']+$RGB['B'])/3,0));
  }


  /**
   *  Calculate the max value from a RGB value
   *
   * @param Array $RGB : RGB object
   * @return Integer : the max value
   */
  static public function RGBtoM($RGB)
  {
    return(max($RGB));
  }


  /**
   *
   * @param Int $rgb : an integer &hRRGGBB
   * @return RGB : a RGB object
   */
  static public function IntToRGB($rgb)
  {
    return(
      Array(
        'R' => ($rgb >> 16) & 0xFF,
        'G' => ($rgb >> 8) & 0xFF,
        'B' => $rgb & 0xFF
      )
    );
  }

  /**
   * convert a string like #rrggbb into a RGB array
   *
   * @param String $rgb : a #rrggbb string
   * @return Array
   */
  static public function StringToRGB($rgb)
  {
    $returned=array(
      'R' => 0,
      'G' => 0,
      'B' => 0
    );

    if(preg_match_all('/^#([A-F0-9]{2})([A-F0-9]{2})([A-F0-9]{2})$/i', $rgb, $values, PREG_SET_ORDER)>0)
    {
      $returned['R']=intval('0x'.$values[0][1],0);
      $returned['G']=intval('0x'.$values[0][2],0);
      $returned['B']=intval('0x'.$values[0][3],0);
    }

    return($returned);
  }

  /**
   * convert a RGB array ('R'=>r, 'G'=>g, 'B'=>b ) into integer value
   *
   * @param Array $rgb : rgb array
   * @return Integer
   */
  static public function RGBToInt($rgb)
  {
    return($rgb['R']*65536 + $rgb['G']*256 + $rgb['B']);
  }

  /**
   * convert a RGB array ('R'=>r, 'G'=>g, 'B'=>b ) into string #rrggbb value
   *
   * @param Array $rgb : rgb array
   * @return String
   */
  static public function RGBToString($rgb)
  {
    return(
      sprintf('#%02X%02X%02X', $rgb['R'], $rgb['G'], $rgb['B'])
    );
  }

  static public function checkHistoOptions($options)
  {
    if(!isset($options['color_bg']) or !is_numeric($options['color_bg'])) $options['color_bg']=0xffffff;
    if(!isset($options['color_v']) or !is_numeric($options['color_v'])) $options['color_v']=0x808080;
    if(!isset($options['color_r']) or !is_numeric($options['color_r'])) $options['color_r']=0xA00000;
    if(!isset($options['color_g']) or !is_numeric($options['color_g'])) $options['color_g']=0x00A000;
    if(!isset($options['color_b']) or !is_numeric($options['color_b'])) $options['color_b']=0x0000A0;

    $modes=array('surface', 'line', 'bar', 'none');
    if(!isset($options['mode_v']) or !in_array($options['mode_v'], $modes)) $options['mode_v']='surface';
    if(!isset($options['mode_r']) or !in_array($options['mode_r'], $modes)) $options['mode_r']='line';
    if(!isset($options['mode_g']) or !in_array($options['mode_g'], $modes)) $options['mode_g']='line';
    if(!isset($options['mode_b']) or !in_array($options['mode_b'], $modes)) $options['mode_b']='line';

    if(!isset($options['histo_width']) or !is_numeric($options['histo_width']) or $options['histo_width']<=0) $options['histo_width']=256;
    if(!isset($options['histo_height']) or !is_numeric($options['histo_height']) or $options['histo_height']<=0) $options['histo_height']=100;
    if(!isset($options['histo_method']) or !in_array($options['histo_method'], array('L', 'A', 'M'))) $options['histo_method']='L';

    return($options);
  }


  static public function colorAllocate($im, $color)
  {
    $rgb=self::IntToRGB($color);
    return(imagecolorallocate($im, $rgb['R'], $rgb['G'], $rgb['B']));
  }

  static public function colorAllocateA($im, $color, $alpha)
  {
    $rgb=self::IntToRGB($color);
    return(imagecolorallocatealpha($im, $rgb['R'], $rgb['G'], $rgb['B'], $alpha));
  }


}


?>