用 PHP 生成条形码

UPC码(Universal Product Code)是最早大规模应用的条码，其特性是一种长度固定、连续性的条码，由於其应用范围广泛，故又被称万用条码。UPC码仅可用来表示数字，故其字码集为数字0~9。UPC码共有A、B、C、D、E等五种版本。本文介绍的就是用 PHP 生成 UPC- A 条形码。

代码:

<?php

function UPCAbarcode($code)
{
	$lw = 2; $hi = 100;
	$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';

	/* UPC-A Must be 11 digits, we compute the checksum. */
	if ( strlen($code) != 11 ) { die("UPC-A Must be 11 digits."); }

	/* 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*95+30,$hi+30);
	$fg = ImageColorAllocate($img, 0, 0, 0);
	$bg = ImageColorAllocate($img, 255, 255, 255);
	ImageFilledRectangle($img, 0, 0, $lw*95+30, $hi+30, $bg);

	$shift=10;

	for ($x=0;$x<strlen($bars);$x++)
	{
		if (($x<10) || ($x>=45 && $x<50) || ($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+17,$hi-5,$code[11],$fg);

	/* Output the Header and Content. */
	header("Content-Type: image/png");
	ImagePNG($img);

}

UPCAbarcode('13322483157');

?>

效果