图片处理：缩放、剪裁、缩放、翻转、旋转、透明、锐化等图片操作

php对图像的各种处理

图片处理：缩放、剪裁、缩放、翻转、旋转、透明、锐化等图片操作

一、创建图片资源

imagecreatetruecolor(width,height);

imagecreatefromgif(图片名称);

imagecreatefrompng(图片名称);

imagecreatefromjpeg(图片名称);

画出各种图像

imagegif(图片资源,保存路径);

imagepng()

imagejpeg();

二、获取图片属性

imagesx(res//宽度

imagesy(res//高度

getimagesize(文件路径)

返回一个具有四个单元的数组。索引 0 包含图像宽度的像素值，索引 1 包含图像高度的像素值。索引 2 是图像类型的标记：1 = GIF，2 = JPG，3 = PNG，4 = SWF，5 = PSD，6 = BMP，7 = TIFF(intel byte order)，8 = TIFF(motorola byte order)，9 = JPC，10 = JP2，11 = JPX，12 = JB2，13 = SWC，14 = IFF，15 = WBMP，16 = XBM。这些标记与 PHP 4.3.0 新加的 IMAGETYPE 常量对应。索引 3 是文本字符串，内容为“height="yyy" width="xxx"”，可直接用于 IMG 标记。

销毁图像资源

imagedestroy(图片资源);

三、透明处理

PNG、jpeg透明色都正常，只有gif不正常

imagecolortransparent(resource image [,int color])//将某个颜色设置成透明色

imagecolorstotal()

imagecolorforindex();

四、图片的裁剪

imagecopyresized()

imagecopyresampled();

五、加水印（文字、图片）

字符串编码转换string�iconv�(�string�$in_charset�,�string�$out_charset�,�string�$str�)

六、图片旋转

imagerotate();//制定角度的图片翻转

七、图片的翻转

沿X轴 � 沿Y轴翻转

八、锐化

imagecolorsforindex()

imagecolorat()

在图片上画图形
   $img=imagecreatefromgif("./images/map.gif");
   $red= imagecolorallocate($img, 255, 0, 0);

   imageline($img, 0, 0, 100, 100, $red);

   imageellipse($img, 200, 100, 100, 100, $red);

   imagegif($img, "./images/map2.gif");

   imagedestroy($img);

图片普通缩放

$filename="./images/hee.jpg";

   $per=0.3;

   list($width, $height)=getimagesize($filename);

   $n_w=$width*$per;
   $n_h=$width*$per;

   $new=imagecreatetruecolor($n_w, $n_h);

   $img=imagecreatefromjpeg($filename);
//拷贝部分图像并调整

   imagecopyresized($new, $img,0, 0,0, 0,$n_w, $n_h, $width, $height);
//图像输出新图片、另存为

   imagejpeg($new, "./images/hee2.jpg");

   imagedestroy($new);
   imagedestroy($img);

图片等比例缩放、没处理透明色

function thumn($background, $width, $height, $newfile) {
   list($s_w, $s_h)=getimagesize($background);//获取原图片高度、宽度

   if ($width && ($s_w < $s_h)) {
    $width = ($height / $s_h) * $s_w;
   } else {
    $height = ($width / $s_w) * $s_h;
   }

   $new=imagecreatetruecolor($width, $height);

   $img=imagecreatefromjpeg($background);

   imagecopyresampled($new, $img, 0, 0, 0, 0, $width, $height, $s_w, $s_h);

   imagejpeg($new, $newfile);

   imagedestroy($new);
   imagedestroy($img);
}

thumn("images/hee.jpg", 200, 200, "./images/hee3.jpg");

gif透明色处理

function thumn($background, $width, $height, $newfile) {
   list($s_w, $s_h)=getimagesize($background);

   if ($width && ($s_w < $s_h)) {
    $width = ($height / $s_h) * $s_w;
   } else {
    $height = ($width / $s_w) * $s_h;
   }

   $new=imagecreatetruecolor($width, $height);

   $img=imagecreatefromgif($background);

   $otsc=imagecolortransparent($img);
   if($otsc >=0 && $otst < imagecolorstotal($img)){//判断索引色
       $tran=imagecolorsforindex($img, $otsc);//索引颜色值

       $newt=imagecolorallocate($new, $tran["red"], $tran["green"], $tran["blue"]);

       imagefill($new, 0, 0, $newt);

       imagecolortransparent($new, $newt);
   }

   imagecopyresized($new, $img, 0, 0, 0, 0, $width, $height, $s_w, $s_h);

   imagegif($new, $newfile);

   imagedestroy($new);
   imagedestroy($img);
}

thumn("images/map.gif", 200, 200, "./images/map3.gif");

图片裁剪

function cut($background, $cut_x, $cut_y, $cut_width, $cut_height, $location){

   $back=imagecreatefromjpeg($background);

   $new=imagecreatetruecolor($cut_width, $cut_height);

   imagecopyresampled($new, $back, 0, 0, $cut_x, $cut_y, $cut_width, $cut_height,$cut_width,$cut_height);

   imagejpeg($new, $location);

   imagedestroy($new);
   imagedestroy($back);
}

cut("./images/hee.jpg", 440, 140, 117, 112, "./images/hee5.jpg");

图片加水印

文字水印

function mark_text($background, $text, $x, $y){
       $back=imagecreatefromjpeg($background);

       $color=imagecolorallocate($back, 0, 255, 0);

       imagettftext($back, 20, 0, $x, $y, $color, "simkai.ttf", $text);

       imagejpeg($back, "./images/hee7.jpg");

       imagedestroy($back);
   }

   mark_text("./images/hee.jpg", "细说PHP", 150, 250);

//图片水印
function mark_pic($background, $waterpic, $x, $y){
$back=imagecreatefromjpeg($background);
$water=imagecreatefromgif($waterpic);
$w_w=imagesx($water);
$w_h=imagesy($water);
imagecopy($back, $water, $x, $y, 0, 0, $w_w, $w_h);
imagejpeg($back,"./images/hee8.jpg");
imagedestroy($back);
imagedestroy($water);
}
mark_pic("./images/hee.jpg", "./images/gaolf.gif", 50, 200);

图片旋转

$back=imagecreatefromjpeg("./images/hee.jpg");

   $new=imagerotate($back, 45, 0);

   imagejpeg($new, "./images/hee9.jpg");

图片水平翻转垂直翻转

function turn_y($background, $newfile){
       $back=imagecreatefromjpeg($background);

       $width=imagesx($back);
       $height=imagesy($back);

       $new=imagecreatetruecolor($width, $height);

       for($x=0; $x < $width; $x++){
           imagecopy($new, $back, $width-$x-1, 0, $x, 0, 1, $height);
       }

       imagejpeg($new, $newfile);

       imagedestroy($back);
       imagedestroy($new);
   }

   function turn_x($background, $newfile){
       $back=imagecreatefromjpeg($background);

       $width=imagesx($back);
       $height=imagesy($back);

       $new=imagecreatetruecolor($width, $height);

       for($y=0; $y < $height; $y++){
           imagecopy($new, $back,0, $height-$y-1, 0, $y, $width, 1);
       }

       imagejpeg($new, $newfile);

       imagedestroy($back);
       imagedestroy($new);
   }

   turn_y("./images/hee.jpg", "./images/hee11.jpg");
   turn_x("./images/hee.jpg", "./images/hee12.jpg");

�图片锐化

function sharp($background, $degree, $save){
   $back=imagecreatefromjpeg($background);

   $b_x=imagesx($back);
   $b_y=imagesy($back);

   $dst=imagecreatefromjpeg($background);
   for($i=0; $i<$b_x; $i++){
       for($j=0; $j<$b_y; $j++){
           $b_clr1=imagecolorsforindex($back, imagecolorat($back, $i-1, $j-1));\\前一个像素颜色数组
           $b_clr2=imagecolorsforindex($back, imagecolorat($back, $i, $j));\\取出当前颜色数组

           $r=intval($b_clr2["red"]+$degree*($b_clr2["red"]-$b_clr1["red"]));\\加深
           $g=intval($b_clr2["green"]+$degree*($b_clr2["green"]-$b_clr1["green"]));
           $b=intval($b_clr2["blue"]+$degree*($b_clr2["blue"]-$b_clr1["blue"]));

           $r=min(255, max($r, 0));//限制r范围在0-255之间
           $g=min(255, max($g, 0));
           $b=min(255, max($b, 0));

           if(($d_clr=imagecolorexact($dst, $r, $g, $b))==-1){//等于1不在颜色范围内
               $d_clr=Imagecolorallocate($dst, $r, $g, $b);//创建一个颜色
           }

           imagesetpixel($dst, $i, $j, $d_clr);
       }

   }
   imagejpeg($dst, $save);
   imagedestroy($back);
   imagedestroy($dst);
}

sharp("./images/hee.jpg", 20, "./images/hee13.jpg");

图片处理：缩放、剪裁、缩放、翻转、旋转、透明、锐化等图片操作

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