php对图像的各种处理函数代码小结
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");