图像处理类（图像信息，缩略图，加水印），有详细的注释
<?php
/**
* 来源：互联网
* 整理：www.phppx.com
*/
class image
{
var $w_pct = 50; //透明度
var $w_quality = 80; //质量
var $w_minwidth = 300; //最小宽
var $w_minheight = 300; //最小高
var $thumb_enable; //是否生成缩略图
var $watermark_enable; //是否生水印
var $interlace = 0; //图像是否为隔行扫描的
var $fontfile; //字体文件
var $w_img ; //默认水印图
function __construct()
{
global $SITE_CONFING;
$this->thumb_enable = $SITE_CONFING['thumb_enable'];
$this->watermark_enable = $SITE_CONFING['watermark_enable'];
$this->set($SITE_CONFING['watermark_minwidth'], $SITE_CONFING['watermark_minheight'], $SITE_CONFING['watermark_quality'], $SITE_CONFING['watermark_pct'], $SITE_CONFING['watermark_fontfile'],$SITE_CONFING['watermark_img']);
}
function image()
{
$this->__construct();
}
function set($w_minwidth = 300, $w_minheight = 300, $w_quality = 80, $w_pct = 100,$fontfile,$w_img)
{
$this->w_minwidth = $w_minwidth;
$this->w_minheight = $w_minheight;
$this->w_quality = $w_quality;
$this->w_pct = $w_pct;
$this->fontfile = $fontfile;
$this->w_img = $w_img;
}
function info($img)
{
$imageinfo = getimagesize($img); //返回图像信息数组 0=>宽的像素 1=>高的像素 2=>是图像类型的标记 3 =>是文本字符串，内容为“height=”yyy” width=”xxx””，
if($imageinfo === false) return false;
$imagetype = strtolower(substr(image_type_to_extension($imageinfo[2]),1)); //获取图像文件类型 $imageinfo[2]是图像类型的标记
$imagesize = filesize($img); //图像大小
$info = array(
’width’=>$imageinfo[0],
’height’=>$imageinfo[1],
’type’=>$imagetype,
’size’=>$imagesize,
’mime’=>$imageinfo['mime']
);
return $info;
}
function thumb($image, $filename = ”, $maxwidth = 200, $maxheight = 50, $suffix=’_thumb’, $autocut = 0)
{
if(!$this->thumb_enable || !$this->check($image)) return false;
$info = $this->info($image); //获取图片信息
if($info === false) return false;
$srcwidth = $info['width']; //源图宽
$srcheight = $info['height']; //源图高
$pathinfo = pathinfo($image);
$type = $pathinfo['extension']; //取得扩展名
if(!$type) $type = $info['type']; //如果没有取到，用$info['type']
$type = strtolower($type);
unset($info);
$scale = min($maxwidth/$srcwidth, $maxheight/$srcheight); //获取缩略比例
//获取按照源图的比列
$createwidth = $width = (int)($srcwidth*$scale); //取得缩略宽
$createheight = $height = (int)($srcheight*$scale); //取得缩略高
$psrc_x = $psrc_y = 0;
if($autocut) //按照缩略图的比例来获取
{
if($maxwidth/$maxheight<$srcwidth/$srcheight && $maxheight>=$height) //如果缩略图按比列比源图窄的话
{
$width = $maxheight/$height*$width; //宽按照相应比例做处理
$height = $maxheight; //高不变
}
elseif($maxwidth/$maxheight>$srcwidth/$srcheight && $maxwidth>=$width)//如果缩略图按比列比源图宽的话
{
$height = $maxwidth/$width*$height;
$width = $maxwidth;
}
$createwidth = $maxwidth;
$createheight = $maxheight;
}
$createfun = ‘imagecreatefrom’.($type==’jpg’ ? ‘jpeg’ : $type); //找到不同的图像处理函数
$srcimg = $createfun($image); //新建图像
if($type != ‘gif’ && function_exists(‘imagecreatetruecolor’))
$thumbimg = imagecreatetruecolor($createwidth, $createheight); //新建一个真彩色图像
else
$thumbimg = imagecreate($width, $height); //新建一个基于调色板的图像
if(function_exists(‘imagecopyresampled’)) //重采样拷贝部分图像并调整大小，真彩
//imagecopyresampled(新图，源图,新图左上角x距离,新图左上角y距离,源图左上角x距离,源图左上角y距离,新图宽,新图高,源图宽,源图高)
imagecopyresampled($thumbimg, $srcimg, 0, 0, $psrc_x, $psrc_y, $width, $height, $srcwidth, $srcheight);
else //拷贝部分图像并调整大小，调色板
imagecopyresized($thumbimg, $srcimg, 0, 0, $psrc_x, $psrc_y, $width, $height, $srcwidth, $srcheight);
if($type==’gif’ || $type==’png’)
{
//imagecolorallocate 为一幅图像分配颜色
$background_color = imagecolorallocate($thumbimg, 0, 255, 0); // 给基于调色板的图像填充背景色， 指派一个绿色
// imagecolortransparent 将某个颜色定义为透明色
imagecolortransparent($thumbimg, $background_color); // 设置为透明色，若注释掉该行则输出绿色的图
}
// imageinterlace 激活或禁止隔行扫描
if($type==’jpg’ || $type==’jpeg’) imageinterlace($thumbimg, $this->interlace);
$imagefun = ‘image’.($type==’jpg’ ? ‘jpeg’ : $type);
//imagejpeg imagegif imagepng
if(empty($filename)) $filename = substr($image, 0, strrpos($image, ‘.’)).$suffix.’.’.$type; //获取文件名
//aaa.gif aaa_thumb.gif
$imagefun($thumbimg, $filename); //新建图像
imagedestroy($thumbimg); //销毁缩略图
imagedestroy($srcimg); //销毁源图
return $filename;
}
//watermark(源图,生成文件,生成位置,水印文件,水印文本,背景色)
function watermark($source, $target = ”, $w_pos = 9, $w_img = ”, $w_text = ”, $w_font = 12, $w_color = ‘#cccccc’)
{
if(!$this->watermark_enable || !$this->check($source)) return false;
if(!$target) $target = $source;
if ($w_img == ” && $w_text == ”)
$w_img = $this->w_img;
$source_info = getimagesize($source);
$source_w = $source_info[0]; //获取宽
$source_h = $source_info[1]; //获取高
if($source_w < $this->w_minwidth || $source_h < $this->w_minheight) return false; //宽和高达不到要求直接返回
switch($source_info[2]) //新建图片
{
case 1 :
$source_img = imagecreatefromgif($source);
break;
case 2 :
$source_img = imagecreatefromjpeg($source);
break;
case 3 :
$source_img = imagecreatefrompng($source);
break;
default :
return false;
}
if(!empty($w_img) && file_exists($w_img)) //水印文件
{
$ifwaterimage = 1; //是否水印图
$water_info = getimagesize($w_img); //水印信息
$width = $water_info[0];
$height = $water_info[1];
switch($water_info[2])
{
case 1 :
$water_img = imagecreatefromgif($w_img);
break;
case 2 :
$water_img = imagecreatefromjpeg($w_img);
break;
case 3 :
$water_img = imagecreatefrompng($w_img);
break;
default :
return;
}
}
else
{
$ifwaterimage = 0;
//imagettfbbox 本函数计算并返回一个包围着 TrueType 文本范围的虚拟方框的像素大小。
//imagettfbbox ( 字体大小, 字体角度, 字体文件,文件 )
$temp = imagettfbbox(ceil($w_font*1.2), 0, $this->fontfile, $w_text);//取得使用 truetype 字体的文本的范围
$width = $temp[4] – $temp[6]; //右上角 X 位置 – 左上角 X 位置
$height = $temp[3] – $temp[5]; //右下角 Y 位置- 右上角 Y 位置
unset($temp);
}
switch($w_pos)
{
case 0: //随机位置
$wx = rand(0,($source_w – $width));
$wy = rand(0,($source_h – $height));
break;
case 1: //左上角
$wx = 5;
$wy = 5;
break;
case 2: //上面中间位置
$wx = ($source_w – $width) / 2;
$wy = 0;
break;
case 3: //右上角
$wx = $source_w – $width;
$wy = 0;
break;
case 4: //左面中间位置
$wx = 0;
$wy = ($source_h – $height) / 2;
break;
case 5: //中间位置
$wx = ($source_w – $width) / 2;
$wy = ($source_h – $height) / 2;
break;
case 6: //底部中间位置
$wx = ($source_w – $width) / 2;
$wy = $source_h – $height;
break;
case 7: //左下角
$wx = 0;
$wy = $source_h – $height;
break;
case 8: //右面中间位置
$wx = $source_w – $width;
$wy = ($source_h – $height) /2;
break;
case 9: //右下角
$wx = $source_w – $width;
$wy = $source_h – $height ;
break;
default: //随机
$wx = rand(0,($source_w – $width));
$wy = rand(0,($source_h – $height));
break;
}
if($ifwaterimage) //如果有水印图
{
//imagecopymerge 拷贝并合并图像的一部分
//参数(源图,水印图,拷贝到源图x位置,拷贝到源图y位置,从水印图x位置,从水印图y位置,高,宽,透明度)
imagecopymerge($source_img, $water_img, $wx, $wy, 0, 0, $width, $height, $this->w_pct);
}
else
{
if(!empty($w_color) && (strlen($w_color)==7))
{
$r = hexdec(substr($w_color,1,2)); //获取红色
$g = hexdec(substr($w_color,3,2)); //获取绿色
$b = hexdec(substr($w_color,5)); //获取蓝色
}
else
{
return;
}
//imagecolorallocate 基于调色板的图像填充背景色
//imagestring 水平地画一行字符串
//imagestring(源图,字体大小,位置X,位置Y,文字,颜色)
//参数($image, float $size, float $angle, int $x, int $y, int $color, string $fontfile, string $text)
imagettftext($source_img,$w_font,0,$wx,$wy,imagecolorallocate($source_img,$r,$g,$b),$this->fontfile,$w_text);
//imagestring($source_img,$w_font,$wx,$wy,$w_text,imagecolorallocate($source_img,$r,$g,$b));
}
//输出到文件或者浏览器
switch($source_info[2])
{
case 1 :
imagegif($source_img, $target); //以 GIF 格式将图像输出到浏览器或文件
break;
case 2 :
imagejpeg($source_img, $target, $this->w_quality); //以 JPEG 格式将图像输出到浏览器或文件
break;
case 3 :
imagepng($source_img, $target); //以 PNG 格式将图像输出到浏览器或文件
break;
default :
return;
}
if(isset($water_info))
{
unset($water_info); //销毁
}
if(isset($water_img))
{
imagedestroy($water_img); //销毁
}
unset($source_info);
imagedestroy($source_img);
return true;
}
//gd库必须存在，后缀为jpg|jpeg|gif|png，文件存在，imagecreatefromjpeg或者imagecreatefromgif存在
function check($image)
{
return extension_loaded(‘gd’) &&
preg_match(“/\.(jpg|jpeg|gif|png)/i”, $image, $m) &&
file_exists($image) &&
function_exists(‘imagecreatefrom’.($m[1] == ‘jpg’ ? ‘jpeg’ : $m[1]));
//imagecreatefromjpeg
//imagecreatefromgif
//imagecreatefrompng
}
}?>
