<?php
class BarCode128 {
  const STARTA = 103;
  const STARTB = 104;
  const STARTC = 105;
  const STOP = 106;
  private $unit_width = 1; //单位宽度 缺省1个象素
  private $is_set_height = false;
  private $width = -1;
  private $heith = 35;
  private $quiet_zone = 6;
  private $font_height = 15;
  private $font_type = 4;
  private $color =0x000000;
  private $bgcolor =0xFFFFFF;
  private $image = null;
  private $codes = array("212222","222122","222221","121223","121322","131222","122213","122312","132212","221213","221312","231212","112232","122132","122231","113222","123122","123221","223211","221132","221231","213212","223112","312131","311222","321122","321221","312212","322112","322211","212123","212321","232121","111323","131123","131321","112313","132113","132311","211313","231113","231311","112133","112331","132131","113123","113321","133121","313121","211331","231131","213113","213311","213131","311123","311321","331121","312113","312311","332111","314111","221411","431111","111224","111422","121124","121421","141122","141221","112214","112412","122114","122411","142112","142211","241211","221114","413111","241112","134111","111242","121142","121241","114212","124112","124211","411212","421112","421211","212141","214121","412121","111143","111341","131141","114113","114311","411113","411311","113141","114131","311141","411131","211412","211214","211412","2331112");
  private $valid_code = -1;
  private $type ='B';
  private $start_codes =array('A'=>self::STARTA,'B'=>self::STARTB,'C'=>self::STARTC);
  private $code ='';
  private $bin_code ='';
  private $text ='';
  public function __construct($code='',$text='',$type='B'){
    if (in_array($type,array('A','B','C')))
      $this->setType($type);
    else
      $this->setType('B');
    if ($code !=='')
      $this->setCode($code);
    if ($text !=='')
      $this->setText($text);
  }
  public function setUnitWidth($unit_width) {
    $this->unit_width = $unit_width;
    $this->quiet_zone = $this->unit_width*6;
    $this->font_height = $this->unit_width*15;
    if (!$this->is_set_height) {
      $this->heith = $this->unit_width*35;
    }
  }
  public function setFontType($font_type){
    $this->font_type = $font_type;
  }
  public function setBgcolor($bgcoloe){
    $this->bgcolor = $bgcoloe;
  }
  public function setColor($color){
    $this->color = $color;
  }
  public function setCode($code){
    if ($code !=''){
      $this->code= $code;
      if ($this->text ==='')
        $this->text = $code;
    }
  }
  public function setText($text){
    $this->text = $text;
  }
  public function setType($type){
    $this->type = $type;
  }
  public function setHeight($height){
    $this->height = $height;
    $this->is_set_height = true;
  }
  private function getValueFromChar($ch){
    $val = ord($ch);
    try{
      if ($this->type =='A') {
        if ($val > 95)
          throw new Exception(' illegal barcode character '.$ch.' for code128A in '.__FILE__.' on line '.__LINE__);
        if ($val < 32)
          $val += 64;
        else
          $val -=32;
      }elseif ($this->type =='B'){
        if ($val < 32 || $val > 127)
          throw new Exception(' illegal barcode character '.$ch.' for code128B in '.__FILE__.' on line '.__LINE__);
        else
          $val -=32;
      }else{
        if (!is_numeric($ch) || (int)$ch < 0 || (int)($ch) > 99)
          throw new Exception(' illegal barcode character '.$ch.' for code128C in '.__FILE__.' on line '.__LINE__);
        else{
          if (strlen($ch) ==1)
            $ch .='0';
          $val = (int)($ch);
        }
      }
    }
    catch(Exception $ex){
      errorlog('die',$ex->getMessage());
    }
    return $val;
  }
  private function parseCode(){
    $this->type=='C'?$step=2:$step=1;
    $val_sum = $this->start_codes[$this->type];
    $this->width = 35;
    $this->bin_code = $this->codes[$val_sum];
    for($i =0;$i<strlen($this->code);$i+=$step){
      $this->width +=11;
      $ch = substr($this->code,$i,$step);
      $val = $this->getValueFromChar($ch);
      $val_sum += $val;
      $this->bin_code .= $this->codes[$val];
    }
    $this->width *=$this->unit_width;
    $val_sum = $val_sum%103;
    $this->valid_code = $val_sum;
    $this->bin_code .= $this->codes[$this->valid_code];
    $this->bin_code .= $this->codes[self::STOP];
  }
  public function getValidCode(){
    if ($this->valid_code == -1)
      $this->parseCode();
    return $this->valid_code;
  }
  public function getWidth(){
    if ($this->width ==-1)
      $this->parseCode();
    return $this->width;
  }
  public function getHeight(){
    if ($this->width ==-1)
      $this->parseCode();
    return $this->height;
  }
  public function createBarCode($image_type ='png',$file_name=null){
    $this->parseCode();
    $this->image = ImageCreate($this->width+2*$this->quiet_zone,$this->heith + $this->font_height);
    $this->bgcolor = imagecolorallocate($this->image,$this->bgcolor >> 16,($this->bgcolor >> 8)&0x00FF,$this->bgcolor & 0xFF);
    $this->color = imagecolorallocate($this->image,$this->color >> 16,($this->color >> 8)&0x00FF,$this->color & 0xFF);
    ImageFilledRectangle($this->image, 0, 0, $this->width + 2*$this->quiet_zone,$this->heith + $this->font_height, $this->bgcolor);
    $sx = $this->quiet_zone;
    $sy = $this->font_height -1;
    $fw = 10; //编号为2或3的字体的宽度为10，为4或5的字体宽度为11
    if ($this->font_type >3){
      $sy++;
      $fw=11;
    }
    $ex = 0;
    $ey = $this->heith + $this->font_height - 2;
    for($i=0;$i<strlen($this->bin_code);$i++){
      $ex = $sx + $this->unit_width*(int) $this->bin_code{$i} -1;
      if ($i%2==0)
        ImageFilledRectangle($this->image, $sx, $sy, $ex,$ey, $this->color);
      $sx =$ex + 1;
    }
    $t_num = strlen($this->text);
    $t_x = $this->width/$t_num;
    $t_sx = ($t_x -$fw)/2;//目的为了使文字居中平均分布
    for($i=0;$i<$t_num;$i++) {
      imagechar($this->image,$this->font_type,6*$this->unit_width +$t_sx +$i*$t_x,0,$this->text{$i},$this->color);
    }
    if (!$file_name) {
      header("Content-Type: image/".$image_type);
    }
    switch ($image_type){
      case 'jpg':
      case 'jpeg':
        Imagejpeg($this->image,$file_name);
        break;
      case 'png':
        Imagepng($this->image,$file_name);
        break;
      case 'gif':
        break;
        Imagegif($this->image,$file_name);
      default:
        Imagepng($this->image,$file_name);
        break;
    }
  }
}
$barcode = new BarCode128('1234567890123AAAA');
$barcode->createBarCode();
?>

宽度、高度可调。

<?php
class test{
  function UPCAbarcode($code) {
    $trans_code = $code;
    $lw = 2.2; $hi = 40;
    $Lencode = array('0001101','0011001','0010011','0111101','0100011',
        '0110001','0101111','0111011','0110111','0001011');
    $Rencode = array('1110010','1100110','1101100','1000010','1011100',
        '1001110','1010000','1000100','1001000','1110100');
    $ends = '101'; $center = '01010';
    /* Compute the EAN-13 Checksum digit */
    $ncode = '0'.$code;
    $even = 0; $odd = 0;
    for ($x=0;$x<12;$x++) {
      if ($x % 2) {
        $odd += $ncode[$x];
      } else { $even += $ncode[$x];
      }
    }
    $code.=(10 - (($odd * 3 + $even) % 10)) % 10;
    /* Create the bar encoding using a binary string */
    $bars=$ends;
    $bars.=$Lencode[$code[0]];
    
    for($x=1;$x<6;$x++) {
      $bars.=$Lencode[$code[$x]];
    }
    $bars.=$center;
    for($x=6;$x<12;$x++) {
      $bars.=$Rencode[$code[$x]];
    }
    $bars.=$ends;
    /* Generate the Barcode Image */
    $img = ImageCreate($lw*75+30,$hi-3);  // 95
    $fg = ImageColorAllocate($img, 0, 0, 0);
    $bg = ImageColorAllocate($img, 255, 255, 255);
    ImageFilledRectangle($img, 0, 0, $lw*75+30, $hi+30, $bg);
    $shift=10;
    for ($x=0;$x<strlen($bars);$x++) {
      if (($x<0) || ($x>=45 && $x<46) || ($x >=85)) {
        $sh=10;
      } else { $sh=0;
      }
      if ($bars[$x] == '1') {
        $color = $fg;
      } else { $color = $bg;
      }
      ImageFilledRectangle($img, ($x*$lw)+15,5,($x+1)*$lw+14,$hi+5+$sh,$color);
    }
    /* Add the Human Readable Label */
    ImageString($img,4,5,$hi-5,$code[0],$fg);
    for ($x=0;$x<5;$x++) {
      ImageString($img,5,$lw*(13+$x*6)+15,$hi+5,$code[$x+1],$fg);
      ImageString($img,5,$lw*(53+$x*6)+15,$hi+5,$code[$x+6],$fg);
    }
    ImageString($img,4,$lw*95-7,$hi,$code[11],$fg);
    /* Output the Header and Content. */
    header("Content-Type: image/png");
    ImagePNG($img);
  }
}
$obj=new test();
echo $obj->UPCAbarcode('201212070099');
?>