This article summarizes some commonly used image processing functions for students, including scaling, cropping, zooming, flipping, rotating, transparency, and sharpening functions. You can refer to them for reference.
Note: If you want to use php gd processing, we need to open the gd library
Enable PHP GD library support under Windows
Find php.ini, open the content and find:
;extension=php_gd2.dll
Remove the semicolon ";" at the front and save it. If there is no semicolon in the first place, it means it is already enabled.
Open GD library in linux
## Check whether the GD library is installed or not using the command
php5 -m | grep -i gd
Or
php -i | grep -i --color gd
##If the GD library is not installed, install it on the server. The method is as follows
### If it is a source code installation, add the parameter
--with-gd
### If it is a Debian Linux system, use apt-get to install it, as follows
apt-get install php5-gd
### If it is a CentOS system, use yum to install it, as follows
yum install php-gd
### If it is a suse-based Linux system, use yast to install it, as follows
yast -i php5_gd
1. Create image resources
imagecreatetruecolor(width,height);
imagecreatefromgif(image name);
imagecreatefrompng(image name);
imagecreatefromjpeg(image name);
Draw various images
imagegif(image resource, save path);
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 values for the width of the image, and index 1 contains the pixel values for the height of the image. Index 2 is the tag of the image type: 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. These tags correspond to the new IMAGETYPE constant added in PHP 4.3.0. Index 3 is a text string with the content "height="yyy" width="xxx"" and can be used directly in the IMG tag. Destroy image resources
imagedestroy(image resource);
3. Transparent processing
The transparent colors of PNG and jpeg are normal, only gif is abnormal
imagecolortransparent(resource image [,int color])//Set a color to be transparent
imagecolorstotal()
imagecolorforindex();
4. Cropping of pictures
imagecopyresized()
imagecopyresampled();
5. Add watermark (text, picture)
String encoding conversion string iconv ( string $in_charset , string $out_charset , string $str )
6. Image rotation
imagerotate(); // Image flip at specified angle
7. Flip of pictures
Flip along the X-axis along the Y-axis
8. Sharpening
imagecolorsforindex()
imagecolorat()
Draw shapes on pictures
$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); normal image scaling
$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);
//Copy part of the image and adjust it
imagecopyresized($new, $img,0, 0,0, 0,$n_w, $n_h, $width, $height);
//Image output new image, save as
imagejpeg($new, "./images/hee2.jpg");
imagedestroy($new);
imagedestroy($img); The image is scaled proportionally and the transparent color is not processed
function thumn($background, $width, $height, $newfile) {
list($s_w, $s_h)=getimagesize($background);//Get the original image height and width
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($img);
}
thumn("images/hee.jpg", 200, 200, "./images/hee3.jpg");gif transparent color processing
function thumn($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));//Limit the range of r to 0-255
$g=min(255, max($g, 0));
$b=min(255, max($b, 0));
if(($d_clr=imagecolorexact($dst, $r, $g, $b))==-1){//Equal to 1 and not within the color range
$d_clr=Imagecolorallocate($dst, $r, $g, $b);//Create a color
}
imagesetpixel($dst, $i, $j, $d_clr);
}
}
imagejpeg($dst, $save);
imagedestroy($back);
imagedestroy($dst);
}
sharp("./images/hee.jpg", 20, "./images/hee13.jpg");October 26th, 2011No comments yet sincerely welcome PHP design, implementation and application verification code class
validationcode.class.php
/* Develop a verification code class
*
* 1. What is verification code
*
* 2. The function of verification code
*
* 3. Write verification code class (PHP image processing)
*
* 4. Use verification code
*
*
*/
class ValidationCode {
private $width;
private $height;
private $codeNum;
private $image; //Image resource
private $disturbColorNum;
private $checkCode;
function __construct($width=80, $height=20, $codeNum=4){
$this->width=$width;
$this->height=$height;
$this->codeNum=$codeNum;
$this->checkCode=$this->createCheckCode();
$number=floor($width*$height/15);
if($number > 240-$codeNum){
$this->disturbColorNum= 240-$codeNum;
}else{
$this->disturbColorNum=$number;
}
}
//Output the image to the browser by accessing this method
function showImage($fontFace=""){
//Step one: Create image background
$this->createImage();
//Step 2: Set up interference elements
$this->setDisturbColor();
//Step 3: Draw random text into the image
$this->outputText($fontFace);
//Step 4: Output image
$this->outputImage();
}
//Get the randomly created verification code string by calling this method
function getCheckCode(){
Return $this->checkCode;
}
private function createImage(){
//Create image resources
$this->image=imagecreatetruecolor($this->width, $this->height);
//Random background color
$backColor=imagecolorallocate($this->image, rand(225, 255), rand(225,255), rand(225, 255));
//Add color to the background
Imagefill($this->image, 0, 0, $backColor);
//Set border color
$border=imagecolorallocate($this->image, 0, 0, 0);
//Draw a rectangular border
Imagerectangle($this->image, 0, 0, $this->width-1, $this->height-1, $border);
}
private function setDisturbColor(){
for($i=0; $i<$this->disturbColorNum; $i++){
$color=imagecolorallocate($this->image, rand(0, 255), rand(0, 255), rand(0, 255));
imagesetpixel($this->image, rand(1, $this->width-2), rand(1, $this->height-2), $color);
}
for($i=0; $i<10; $i++){
$color=imagecolorallocate($this->image, rand(200, 255), rand(200, 255), rand(200, 255));
imagearc($this->image, rand(-10, $this->width), rand(-10, $this->height), rand(30, 300), rand(20, 200), 55 , 44, $color);
}
}
private function createCheckCode(){
$code="23456789abcdefghijkmnpqrstuvwxyzABCDEFGHIJKMNPQRSTUVWXYZ";
$string='';
for($i=0; $i < $this->codeNum; $i++){
$char=$code{rand(0, strlen($code)-1)};
$string.=$char;
}
return $string;
}
private function outputText($fontFace=""){
for($i=0; $i<$this->codeNum; $i++){
$fontcolor=imagecolorallocate($this->image, rand(0, 128), rand(0, 128), rand(0, 128));
if($fontFace==""){
$fontsize=rand(3, 5);
$x=floor($this->width/$this->codeNum)*$i+3;
$y=rand(0, $this->height-15);
imagechar($this->image,$fontsize, $x, $y, $this->checkCode{$i},$fontcolor);
}else{
$fontsize=rand(12, 16);
$x=floor(($this->width-8)/$this->codeNum)*$i+8;
$y=rand($fontSize+5, $this->height);
imagettftext($this->image,$fontsize,rand(-30, 30),$x,$y ,$fontcolor, $fontFace, $this->checkCode{$i});
}
}
}
private function outputImage() {
if(imagetypes() & IMG_GIF){
header("Content-Type:image/gif");
imagepng($this->image);
}else if(imagetypes() & IMG_JPG){
header("Content-Type:image/jpeg");
imagepng($this->image);
}else if(imagetypes() & IMG_PNG){
header("Content-Type:image/png");
imagepng($this->image);
}else if(imagetypes() & IMG_WBMP){
header("Content-Type:image/vnd.wap.wbmp");
imagepng($this->image);
}else{
die("PHP不支持图像创建");
}
}
function __destruct(){
imagedestroy($this->image);
}
}code.php
session_start();
include "validationcode.class.php";
$code=new ValidationCode(80, 20, 4);
$code->showImage(); //输出到页面中供 注册或登录使用
$_SESSION["code"]=$code->getCheckCode(); //将验证码保存到服务器中demo.php
session_start();
echo $_POST["code"]."
";
echo $_SESSION["code"]."
";
if(strtoupper($_POST["code"])==strtoupper($_SESSION["code"])){
echo "ok";
}else{
echo "error";
}
?>
1、画图
验证码，统计图
安装GD库（图片处理库）
■创建一个画布—-创建资源类型——–高度、宽度
■绘制图像
1、制定各种颜色
2、矩形、园、点、线段、扇形、画字（字符、字符串、freetype字体），每一个图像对应一个函数
■输出图像/保存处理好的图像
1、输出各种类型（gif、png、jpeg）
imagegif();
imagepng();
imagegpeg();
■Release resources
//step 1Create image resources
$img=imagecreatetruecolor(200,200);
$red=imagecolorallocate($img,255,0,0);
$yellow=imagecolorallocate($img,255,255,0);
$green=imagecolorallocate($img,0,255,0);
$blue=imagecolorallocate($img,0,0,255);
imagefill($img,0,0,$yellow);//Color filling
//step2 draw various graphics
imagefilledrectangle($img,10,10,80,80,$red);//Draw a rectangle and fill it
imagerectangle($img,10,10,80,80,$red));//Draw a rectangle without filling it and fill it with color
//Line segment
imageline($img,0, 0, 200, 200 ,$blue);
imageline($img,200, 0, 0, 200, $blue);
//Click
imagesetpixel($img,50, 50 ,$red);
imagesetpixel($img,55, 50,$red);
imagesetpixel($img,59, 50,$red);
imagesetpixel($img,64, 50,$red);
imagesetpixel($img,72, 50,$red);
// Circle
imageellipse($img, 100, 100, 100, 100,$green);
//Circle
imagefilledellipse($img, 100, 100, 10, 10,$blue);
Border
//Output image or save image
header("Content-Type:img/gif");
imagegif($img);
//Release resources
imagedestory($img);
Draw a pie chart
//step 1 Create image resources
$img=imagecreatetruecolor(200, 200);
// $img=imagecreate(200, 200);
$white=imagecolorallocate($img, 255, 255, 255);
$gray=imagecolorallocate($img, 0xC0, 0xC0, 0xC0);
$darkgray=imagecolorallocate($img, 0x90, 0x90, 0x90);
$navy=imagecolorallocate($img, 0, 0, 0x80);
$darknavy=imagecolorallocate($img, 0, 0, 0x50);
$red= imagecolorallocate($img, 0xFF, 0, 0);
$darkred=imagecolorallocate($img, 0x90, 0, 0);
imagefill($img, 0, 0, $white);
//3D effect
for($i=60; $i>50; $i--){
imagefilledarc($img, 50, $i,100, 50, -160, 40, $darkgray, IMG_ARC_PIE);
imagefilledarc($img, 50, $i,100, 50, 40, 75, $darknavy, IMG_ARC_PIE);
imagefilledarc($img, 50, $i,100, 50, 75, 200, $darkred, IMG_ARC_PIE);
}
imagefilledarc($img, 50, $i,100, 50, -160, 40, $gray, IMG_ARC_PIE);
imagefilledarc($img, 50, $i,100, 50, 40, 75, $navy, IMG_ARC_PIE);
imagefilledarc($img, 50, $i,100, 50, 75, 200, $red, IMG_ARC_PIE);
header("Content-Type:image/gif");
imagegif($img);
//Release resources
imagedestroy($img); draw text
//step 1Create image resources
$img=imagecreatetruecolor(200, 200);
// $img=imagecreate(200, 200);
$white=imagecolorallocate($img, 255, 255, 255);
$gray=imagecolorallocate($img, 0xC0, 0xC0, 0xC0);
$darkgray=imagecolorallocate($img, 0x90, 0x90, 0x90);
$navy=imagecolorallocate($img, 0, 0, 0x80);
$darknavy=imagecolorallocate($img, 0, 0, 0x50);
$red= imagecolorallocate($img, 0xFF, 0, 0);
$darkred=imagecolorallocate($img, 0x90, 0, 0);
imagefill($img, 0, 0, $gray);
imagechar($img, 5, 100, 100, "A", $red);
imagechar($img, 5, 120, 120, "B", $red);
imagecharup($img, 5, 60, 60, "C", $red);
imagecharup($img, 5, 80, 80, "D", $red);
imagestring($img, 3, 10, 10, "Hello", $navy);
imagestringup($img, 3, 10, 80, "Hello", $navy);
imagettftext($img, 25, 60, 150, 150, $red, "simkai.ttf", "##");
imagettftext($img, 12, -60, 50, 150, $red, "simli.ttf", "##");
header("Content-Type:image/gif");
imagegif($img);
//Release resources
imagedestroy($img);2. Process the original image
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