(Advanced) PHP image processing functions and code examples

1. Create image resources

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();

2. Get image attributes
imagesx(res//width
imagesy(res//height
getimagesize(file path)
Returns an array with four cells. Index 0 contains the pixel value of the image width, index 2 contains the pixel value of the image type: 1 = GIF, 2 = JPG, 3 = PNG. = 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. These tags correspond to the new IMAGETYPE constant in PHP 4.3.0. Index 3 is a text string with the content "height="yyy" width="xxx"" and can be used directly. Marked in IMG.
Destroy image resources
imagedestroy(picture resources);

3. Transparency processing
PNG and jpeg transparent colors are normal, only gif is abnormal

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

4. Cropping of pictures

imagecopyresized()
imagecopyresampled();

5. Adding watermark (text, picture)
String encoding conversion string iconv (string $in_charset, string $out_charset, string $str)

6. Image rotation
imagerotate();//Flip the picture at a specified angle

7. Flip the picture
Flip along the X axis and along the Y axis

8. Sharpen

imagecolorsforindex()
imagecolorat()

Draw graphics on the picture $img=imagecreatefromgif("./images/map.gif");

.The code is as follows:

<?PHP
 /**
 * 图片锐化处理
 */
 $red= imagecolorallocate($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);

Normal scaling of pictures
The code is as follows:

$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);

The picture is scaled in equal proportions without processing transparent colors
The code is as follows:

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 transparent color processing
The code is as follows:

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");

Picture cropping

.The code is as follows:

<?php
/**
* 图片裁剪处理
* edit by www.jbxue.com
*/
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");
?>

Add watermark to picture and text watermark

.The code is as follows:

<?PHP /** 
*  
* 图片添加文字水印 
*/ 
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);
?>

Picture rotation

.The code is as follows:

<?PHP
 /**
 * 图片旋转
 */
 $back=imagecreatefromjpeg("./images/hee.jpg");
 $new=imagerotate($back, 45, 0);
 imagejpeg($new, "./images/hee9.jpg");
 ?>

Flip the image horizontally and flip vertically

. The code is as follows:

<?php
 /**
 * 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");
 ?>

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