PHP第十课 PHP图像处理函数以及验证码实现

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概要:

gd库画图:

数学函数

PHP图片处理函数

图片处理函数使用场景

1.验证码
2.缩放
3.裁剪
4.水印

gd库画图:


1.准备画布
2.准备涂料
3.画画
4.输出图片
5.保存图片
6.关闭画布

<?php //准备画布$im = imagecreatetruecolor(500, 300);//准备涂料$black = imagecolorallocate($im, 0, 0, 0);$white = imagecolorallocate($im, 255, 255, 255);//背景填充成黑色imagefill($im,0,0, $black);//画一个矩形,填充成白色imagefilledellipse($im, 258, 151, 200, 200, $white);//输出到浏览器或保存起来header("content-type:image/png");//输出图片imagepng($im);//关闭画布imagedestroy($im);?>

PHP图片处理函数
1.数学函数
2.图片处理函数




数学函数:
1.max();
2.min();
3.mt_rand();随机取一个数字

<?php echomt_rand(1,5);?>

mt_rand随机取一个值

<?php //随机从一个数组中取一个值$arr = array("a","b","c","d","e");$rkey = mt_rand(0,count($arr)-1);echo $arr[$rkey];?>

4.ceil();天花板 
5.floor();
6.round();四舍五入

<?php echo ceil(2.4);//3echo floor(2.4);//2echo round(2.4);//2echo round(2.6);//3?>

6.pi(); //π 取圆周率

<?php echo(pi());echo M_PI;?>

图片处理函数使用场景

1.验证码
2.缩放
3.裁剪
4.水印

PHP中穿件图像的五个步骤
1.准备画布
2.准备涂料
3.在画布上画图像或者文字
4.输出最终图像或曹村最终图像
5.释放画布资源

<?php //1.准备画布$im = imagecreatetruecolor(500,300);//2.准备涂料$black = imagecolorallocate($im, 0, 0, 0);$white = imagecolorallocate($im, 255, 255, 255);//3.在画布上画图像或者文字//如果不填充背景,默认是黑色imageellipse($im,258,151,200,200,$white);//4.输出最终图像或保存最终图像header("content-type:image/png");imagepng($im);//5.释放画布资源imagedestroy($im);?>

绘制图像:
imagefill();
imagesetpixel();//画像素点
imageline();//画线
imagerectangle();//画一个矩形
imagepolygon();//画一个多边形
imageellipse();//画一个椭圆
imageare();画一个圆弧
imagechar();//水平的画一个字符
imagestring();//水平的画一行字符串

//画线<?php //1.准备画布$im = imagecreatetruecolor(500,300);//2.准备涂料$black = imagecolorallocate($im, 0, 0, 0);$white = imagecolorallocate($im, 255, 255, 255);//3.在画布上画图像或者文字//如果不填充背景,默认是黑色imageline($im,0,0,500,300,$white);imageline($im,0,300,500,0,$white);imageline($im,0,150,500,150,$white);imageline($im,250,0,250,300,$white);//4.输出最终图像或保存最终图像header("content-type:image/png");imagepng($im);//5.释放画布资源imagedestroy($im);?>

//添加干扰素<?php //1.准备画布$im = imagecreatetruecolor(500,300);//2.准备涂料$black = imagecolorallocate($im, 0, 0, 0);$white = imagecolorallocate($im, 255, 255, 255);//3.在画布上画图像或者文字//产生随机的点for ($i=0; $i < 1000; $i++) { imagesetpixel($im,mt_rand(0,500),mt_rand(0,300),$white);}//产生随机的线for ($j=0; $j < 100; $j++) { imageline($im, mt_rand(0,500), mt_rand(0,300), mt_rand(0,500), mt_rand(0,300), $white);}//4.输出最终图像或保存最终图像header("content-type:image/png");imagepng($im);//5.释放画布资源imagedestroy($im);?>

//画矩形:<?php //1.准备画布$im = imagecreatetruecolor(500,300);//2.准备涂料$black = imagecolorallocate($im, 0, 0, 0);$white = imagecolorallocate($im, 255, 255, 255);//3.在画布上画图像或者文字imagerectangle($im, 20, 20, 480, 280, $white);//imagefilledrectangle($im, 20, 20, 480, 280, $white);//填充//4.输出最终图像或保存最终图像header("content-type:image/png");imagepng($im);//5.释放画布资源imagedestroy($im);?>

//imagepolygon 画多边形_画三角形<?php //1.准备画布$im = imagecreatetruecolor(500,300);//2.准备涂料$black = imagecolorallocate($im, 0, 0, 0);$white = imagecolorallocate($im, 255, 255, 255);//3.在画布上画图像或者文字$arr = array(250,20,60,240,440,240);imagepolygon($im, $arr, 3, $white);//4.输出最终图像或保存最终图像header("content-type:image/png");imagepng($im);//5.释放画布资源imagedestroy($im);?>

画一个3D饼状图<?php //1.准备画布$im = imagecreatetruecolor(500,300);//2.准备涂料$black = imagecolorallocate($im, 0, 0, 0);$red = imagecolorallocate($im, 255, 0, 0);$grayred = imagecolorallocate($im, 255, 100, 100);$green = imagecolorallocate($im, 0, 255, 0);$blue = imagecolorallocate($im, 0, 0, 255);$gray = imagecolorallocate($im, 200, 200, 200);$white = imagecolorallocate($im, 255, 255, 255);//3.在画布上画图像或者文字for ($i=0; $i < 10; $i++) { imagefilledarc($im, 250, 150+$i, 200, 200, 0, 70, $gray,IMG_ARC_PIE);imagefilledarc($im, 250, 150+$i, 200, 200, 70, 190, $grayred,IMG_ARC_PIE);imagefilledarc($im, 250, 150+$i, 200, 200, 190, 270, $green,IMG_ARC_PIE);imagefilledarc($im, 250, 150+$i, 200, 200, 270, 360, $blue,IMG_ARC_PIE);}imagefilledarc($im, 250, 150, 200, 200, 0, 70, $white,IMG_ARC_PIE);imagefilledarc($im, 250, 150, 200, 200, 70, 190, $red,IMG_ARC_PIE);imagefilledarc($im, 250, 150, 200, 200, 190, 270, $green,IMG_ARC_PIE);imagefilledarc($im, 250, 150, 200, 200, 270, 360, $blue,IMG_ARC_PIE);//4.输出最终图像或保存最终图像header("content-type:image/png");imagepng($im);//5.释放画布资源imagedestroy($im);?>

转载请注明出处: http://blog.csdn.net/junzaivip

//写文字:<?php //1.准备画布$im = imagecreatetruecolor(500,300);//2.准备涂料$black = imagecolorallocate($im, 0, 0, 0);$red = imagecolorallocate($im, 255, 0, 0);$grayred = imagecolorallocate($im, 255, 100, 100);$green = imagecolorallocate($im, 0, 255, 0);$blue = imagecolorallocate($im, 0, 0, 255);$gray = imagecolorallocate($im, 200, 200, 200);$white = imagecolorallocate($im, 255, 255, 255);//3.在画布上画图像或者文字$str= "PHP is very much";imagestring($im, 5, 260, 160, $str, $green);//4.输出最终图像或保存最终图像header("content-type:image/png");imagepng($im);//5.释放画布资源imagedestroy($im);?>

//写单个字符:<?php //1.准备画布$im = imagecreatetruecolor(500,300);//2.准备涂料$black = imagecolorallocate($im, 0, 0, 0);$red = imagecolorallocate($im, 255, 0, 0);$grayred = imagecolorallocate($im, 255, 100, 100);$green = imagecolorallocate($im, 0, 255, 0);$blue = imagecolorallocate($im, 0, 0, 255);$gray = imagecolorallocate($im, 200, 200, 200);$white = imagecolorallocate($im, 255, 255, 255);//3.在画布上画图像或者文字$str= "P";imagechar($im, 5, 260, 160, $str, $green);//4.输出最终图像或保存最终图像header("content-type:image/png");imagepng($im);//5.释放画布资源imagedestroy($im);?>

//在图片上面写字<?php //1.准备画布$im = imagecreatetruecolor(500,300);//2.准备涂料$black = imagecolorallocate($im, 0, 0, 0);$red = imagecolorallocate($im, 255, 0, 0);$grayred = imagecolorallocate($im, 255, 100, 100);$green = imagecolorallocate($im, 0, 255, 0);$blue = imagecolorallocate($im, 0, 0, 255);$gray = imagecolorallocate($im, 200, 200, 200);$white = imagecolorallocate($im, 255, 255, 255);//3.在画布上画图像或者文字$str= "junzaivip";$file = "E:/PHP/fonts/SIMYOU.TTF";// $file = "fonts/SIMYOU.TTF";imagettftext($im, 50, 0, 100, 200, $green, $file, $str);//4.输出最终图像或保存最终图像header("content-type:image/png");imagepng($im);//5.释放画布资源imagedestroy($im);?>

PHP 验证码的设计

<?php //准备画布$im = imagecreatetruecolor(100,50);//准备涂料$black = imagecolorallocate($im, 0, 0, 0);$gray = imagecolorallocate($im, 200, 200, 200);//填充背景imagefill($im, 0, 0, $gray);//文字坐标$x = (100-4*20)/2 + 6;$y = (50-20)/2 + 20;//在画布上画图像或者文字//把三个数组联系起来$strarr = array_merge(range(1, 9),range(a, z),range(A, Z));//打乱数组shuffle($strarr);//array_slice:取数组的前几位//Join 将数组变成字符串,并且以第一个变量做分隔符$str = join('',array_slice($strarr, 0,4));$file = "E:/PHP/fonts/msyh.ttf";// $file = "fonts/msyh.ttf";imagettftext($im, 20, 0, $x, $y, $black, $file, $str);//输出最终图像或保存最终图像header("content-type:image/png");imagepng($im);//释放画布资源imagedestroy($im);?>

php验证码设计:这里涉及到两个页面:index.php & reg.php
说明:


这个验证码版本只实现了验证图片的动态获取
前台注册页面的验证码和生成图片的验证码进行比较
验证码是由数字 小写字母 大写字母 随机组成


index.php//实现用户的注册

<html><head><title>reg</title><style type="text/css">table{border-collapse: collapse;}</style></head><body><h2>用户注册页面</h2><hr><table widtd = "500px" border = "1px"><form action = "reg.php" method = "post"><tr><td>姓   名:</td><td colspan = "2"><input type = "text" name="username" id = ""></td></tr><tr><td>密   码:</td><td colspan = "2"><input type = "password" name="password" id = ""></td></tr><tr><td>验证码:</td><td align = "center" valign = "middle"><input type = "text" id = "auth" name = "vcode"> </td><td><img src="auth.php"></tr><tr><td><input type = "submit" value = "submit" name = "submit"></td><td colspan = "2"><input type = "reset" value = "重置" name = "submit"></td></tr></form></table></body></html>

reg.php//用来验证验证码是否正确

<?phpsession_start();// echo $_POST['username'];// echo $_POST['password'];$code = strtolower($_POST['vcode']);// echo $code;// echo "<pre>";// print_r($_SESSION);// echo "</pre>";$vstr = strtolower($_SESSION['vstr']);if ($code==$vstr) {//实现页面的跳转echo "<script>location='http://www.baidu.com'</script>";}else{echo "<script>alert('验证码输入错误')</script>";//echo "<a href='index.php'>返回注册页面</a>";echo "<script>location='index.php'</script>";}?>

auth.php 用来生成验证码

<?php //开启session,开启session之前,不能有任何输出session_start();$width = 50;//验证码背景宽度$height = 26;//验证码背景高速$fonttype = 10;//验证码中字的大小//准备画布$im = imagecreatetruecolor($width,$height);//准备涂料$black = imagecolorallocate($im, 0, 0, 0);$gray = imagecolorallocate($im, 200, 200, 200);//填充背景imagefill($im, 0, 0, $gray);//文字坐标$x = ($width-4*$fonttype)/2 +2;$y = ($height-$fonttype)/2 + $fonttype;//在画布上画图像或者文字//把三个数组联系起来$strarr = array_merge(range(1, 9),range(a, z),range(A, Z));//打乱数组shuffle($strarr);//array_slice:取数组的前几位//Join 将数组变成字符串,并且以第一个变量做分隔符$str = join('',array_slice($strarr, 0,4));//把$str放入session中,可方便所有页面使用$_SESSION['vstr'] = $str;$file = "E:/PHP/fonts/msyh.ttf";// $file = "fonts/msyh.ttf";imagettftext($im, $fonttype, 0, $x, $y, $black, $file, $str);//输出最终图像或保存最终图像header("content-type:image/png");imagepng($im);//释放画布资源imagedestroy($im);?>

php验证码设计:
页面跳转:
1.php跳转
header("location:index.php");


2.js跳转(建议使用)
echo "<script>location = 'http://www.baidu.com'</script>";
echo "<script>location = 'index.php'</script>";


js弹窗:
echo '<script>alert("验证码有误,请重新输入")</script>';


2.缩放
获取图片的宽高
1.getimagesize(); //得到图片的大小  可以直接通过图片("lyf.jpg")就可以获取图片的所有信息
2.imagesx();//得到图片的宽 必须先获取图片的资源(imagecreatefromjpeg("lyf.jpg");),才能得到图片的信息
3.imagesy();//得到图片的高 必须先获取图片的资源,才能得到图片的信息

已经存在的图片形成画布资源:
1.imagecreatefromjpeg();

<?php$im = imagecreatefromjpeg("lyf.jpg");$x = imagesx($im);$y = imagesy($im);echo $x . $y;exit;header("content-type:image/jpeg");imagejpeg($im);?>

方法二获取图片的大小:

<?php$imgfile = "lyf.jpg";$imgarr = getimagesize($imgfile);echo "<pre>";print_r($imgarr);echo "</pre>";exit;$im = imagecreatefromjpeg("lyf.jpg");echo $x . $y;header("content-type:image/jpeg");imagejpeg($im);?>

  图片缩放函数:
  imagecopyresampled();

  图片等比例缩放:

 <?php$imgfile = "lyf.jpg";//为了得到大图的宽高$imgarr = getimagesize($imgfile);$maxw = $imgarr[0];$maxh = $imgarr[1];$maxt = $imgarr[2];$maxm = $imgarr['mime'];//为了把大图变为资源$im = imagecreatefromjpeg("lyf.jpg");//小图资源$minw = 100;$minh = 400;//等比例缩放if (($minw/$maxw)>($minh/$maxh)) {$rate =  $minh/$maxh ;}else{$rate =  $minw / $maxw ;}$minw = floor($maxw * $rate);$minh = floor($maxh * $rate);$minim = imagecreatetruecolor($minw, $minh);//把大图缩放成小图imagecopyresampled($minim, $im, 0, 0, 0, 0, $minw, $minh, $maxw, $maxh);//小图输出header("content-type:{$maxm}");//判断类型switch ($maxt) {case 1:$imageout = "imagegif";break;case 2:$imageout = "imagejpeg";break;case 3:$imageout = "imagepng";break;}$imageout($minim);$minfilename = "s_".$imgfile;$imageout($minim,$minfilename);// imagejpeg($im);//释放资源imagedestroy($maxim);imagedestroy($minim);?>

  图片裁剪函数:
  imagecopyresampled();


  图片水印函数:
  imagecopy();




3.裁剪
4.水印

<?php $maxim = imagecreatefromjpeg("lyf.jpg");$minim = imagecreatefromjpeg("lyf.jpg");$maxw = imagesx($maxim);$maxh = imagesy($maxim);$minw = imagesx($minim);$minh = imagesy($minim);imagecopy($maxim, $minim, $maxw-$minw, $maxh-$minh, 0, 0, $minw, $minh);header("content-type:image/jpeg");imagejpeg($mamim); ?>