PHPimagecopy()与imagecopymerge()图像添加水印_PHP教程

header("Content-type: image/jpeg");

//原始图像
$dst = "images/flower_1.jpg";

//得到原始图片信息
$dst_im = imagecreatefromjpeg($dst);
$dst_info = getimagesize($dst);

//水印图像
$src = "images/logo.gif";
$src_im = imagecreatefromgif($src);
$src_info = getimagesize($src);

//水印透明度
$alpha = 30;

//合并水印图片
imagecopymerge($dst_im,$src_im,$dst_info[0]-$src_info[0],$dst_info[1]-$src_info[1],0,0,$src_info[0],
$src_info[1],$alpha);

//输出合并后水印图片
imagejpeg($dst_im);
imagedestroy($dst_im);
imagedestroy($src_im);
?>

新版本之后imagecopymerge函数几乎不使用了，我们可直接使用imagecopy来生成水印两个函数的功能是完全一样的。

//增加水印
$watermark =1;
$watertype =2;
$waterstring ='';
$waterimg="z.png"; //水印图片
$sFilePath ='aa.jpg';
if($watermark==1)
{
$image_size = getimagesize($sFilePath); //上传的图片
$water_size = getimagesize($waterimg); //水印图片
$iinfo=getimagesize($sFilePath,$iinfo);
$nimage=imagecreatetruecolor($image_size[0],$image_size[1]);
$white=imagecolorallocate($nimage,255,255,255);
$black=imagecolorallocate($nimage,0,0,0);
$red=imagecolorallocate($nimage,255,0,0);
imagefill($nimage,0,0,$white);
switch ($iinfo[2])
{
case 1:
$simage =imagecreatefromgif($sFilePath);
break;
case 2:
$simage =imagecreatefromjpeg($sFilePath);
break;
case 3:
$simage =imagecreatefrompng($sFilePath);
break;
// case 6:
// $simage =imagecreatefromwbmp($sFilePath);
// break;
default:
die("不支持的文件类型");
exit;
}

imagecopy($nimage,$simage,0,0,0,0,$image_size[0],$image_size[1]);

switch($watertype)
{
case 1: //加水印字符串
imagestring($nimage,2,3,$image_size[1]-15,$waterstring,$black);
break;
case 2: //加水印图片
$simage1 =imagecreatefrompng($waterimg);
$x= $image_size[0]-$water_size[0];
$y= $image_size[1]-$water_size[1];
imagecopy($nimage,$simage1,$x,$y,0,0,240,65);
imagedestroy($simage1);
break;
}

switch ($iinfo[2])
{
case 1:
imagegif($nimage, $sFilePath);
// imagejpeg($nimage, $sFilePath);
break;
case 2:
imagejpeg($nimage, $sFilePath);
break;
case 3:
imagepng($nimage, $sFilePath);
break;
// case 6:
// imagewbmp($nimage, $sFilePath);
// //imagejpeg($nimage, $sFilePath);
// break;
}

//覆盖原上传文件
imagedestroy($nimage);
imagedestroy($simage);
}

class ImageTool {
// imageInfo 分析图片的信息
// return array()
public static function imageInfo($image) {
// 判断图片是否存在
if (!file_exists($image)) {
return false;
}

$info = getimagesize($image);

if ($info == false) {
return false;
}

// 此时info分析出来,是一个数组
$img['width'] = $info[0];
$img['height'] = $info[1];
$img['ext'] = substr($info['mime'], strpos($info['mime'], '/') + 1);

return $img;
}

/*
加水印功能
parm String $dst 等操作图片
parm String $water 水印小图
parm String $save,不填则默认替换原始图
*/
public static function water($dst, $water, $save = NULL, $pos = 2, $alpha = 50) {
// 先保证2个图片存在
if (!file_exists($dst) || !file_exists($water)) {
return false;
}

// 首先保证水印不能比待操作图片还大
$dinfo = self::imageInfo($dst);
$winfo = self::imageInfo($water);

if ($winfo['height'] > $dinfo['height'] || $winfo['width'] > $dinfo['width']) {
return false;
}

// 两张图,读到画布上! 但是图片可能是png,可能是jpeg,用什么函数读?
$dfunc = 'imagecreatefrom' . $dinfo['ext'];
$wfunc = 'imagecreatefrom' . $winfo['ext'];

if (!function_exists($dfunc) || !function_exists($wfunc)) {
return false;
}

// 动态加载函数来创建画布
$dim = $dfunc($dst);
// 创建待操作的画布
$wim = $wfunc($water);
// 创建水印画布

// 根据水印的位置 计算粘贴的坐标
switch($pos) {
case 0 :
// 左上角
$posx = 0;
$posy = 0;
break;

case 1 :
// 右上角
$posx = $dinfo['width'] - $winfo['width'];
$posy = 0;
break;

case 3 :
// 左下角
$posx = 0;
$posy = $dinfo['height'] - $winfo['height'];
break;

default :
$posx = $dinfo['width'] - $winfo['width'];
$posy = $dinfo['height'] - $winfo['height'];
}

// 加水印
imagecopymerge($dim, $wim, $posx, $posy, 0, 0, $winfo['width'], $winfo['height'], $alpha);

// 保存
if (!$save) {
$save = $dst;
unlink($dst);
// 删除原图
}

$createfunc = 'image' . $dinfo['ext'];
$createfunc($dim, $save);

imagedestroy($dim);
imagedestroy($wim);

return true;
}

/**
thumb 生成缩略图
等比例缩放,两边留白
**/
public static function thumb($dst, $save = NULL, $width = 200, $height = 200) {
// 首先判断待处理的图片存不存在
$dinfo = self::imageInfo($dst);
if ($dinfo == false) {
return false;
}

// 计算缩放比例
$calc = min($width / $dinfo['width'], $height / $dinfo['height']);

// 创建原始图的画布
$dfunc = 'imagecreatefrom' . $dinfo['ext'];
$dim = $dfunc($dst);

// 创建缩略画布
$tim = imagecreatetruecolor($width, $height);

// 创建白色填充缩略画布
$white = imagecolorallocate($tim, 255, 255, 255);

// 填充缩略画布
imagefill($tim, 0, 0, $white);

// 复制并缩略
$dwidth = (int)$dinfo['width'] * $calc;
$dheight = (int)$dinfo['height'] * $calc;

$paddingx = (int)($width - $dwidth) / 2;
$paddingy = (int)($height - $dheight) / 2;

imagecopyresampled($tim, $dim, $paddingx, $paddingy, 0, 0, $dwidth, $dheight, $dinfo['width'],

$dinfo['height']);

// 保存图片
if (!$save) {
$save = $dst;
unlink($dst);
}

$createfunc = 'image' . $dinfo['ext'];
$createfunc($tim, $save);

imagedestroy($dim);
imagedestroy($tim);

return true;

}

}