php imagecreatefromgif创建 gif图片
imagecreatefromgif（$filename）
imagecreatefromgif（）返回一个图像标识符代表从给定的文件名获得的图像
$filename是gif图片名称哦。
来看个实例
<?php
function LoadGif($imgname)
{
/* Attempt to open */
$im = @imagecreatefromgif($imgname);
/* See if it failed */
if(!$im)
{
/* Create a blank image */
$im = imagecreatetruecolor (150, 30);
$bgc = imagecolorallocate ($im, 255, 255, 255);
$tc = imagecolorallocate ($im, 0, 0, 0);
imagefilledrectangle ($im, 0, 0, 150, 30, $bgc);
/* Output an error message */
imagestring ($im, 1, 5, 5, 'Error loading ' . $imgname, $tc);
}
return $im;
}
header('Content-Type: image/gif');
$img = LoadGif('bogus.image');
imagegif($img);
imagedestroy($img);
?>
<?php教程
class My_Lib_simpleimage {
var $image;
var $image_type;
function load($filename) {
//$filename 文件的临时文件名 $_FILES['name']['tmp_name']
$image_info = getimagesize($filename);
$this->image_type = $image_info[2];
if( $this->image_type == IMAGETYPE_JPEG ) {
$this->image = imagecreatefromjpeg($filename);
} elseif( $this->image_type == IMAGETYPE_GIF ) {
$this->image = imagecreatefromgif($filename);
} elseif( $this->image_type == IMAGETYPE_PNG ) {
$this->image = imagecreatefrompng($filename);
}
}
function save($filename, $image_type=IMAGETYPE_JPEG, $compression=75, $permissions=null) {
if( $image_type == IMAGETYPE_JPEG ) {
imagejpeg($this->image,$filename,$compression);
} elseif( $image_type == IMAGETYPE_GIF ) {
imagegif($this->image,$filename);
} elseif( $image_type == IMAGETYPE_PNG ) {
imagepng($this->image,$filename);
}
if( $permissions != null) {
chmod($filename,$permissions);
}
}
function output($image_type=IMAGETYPE_JPEG) {
if( $image_type == IMAGETYPE_JPEG ) {
imagejpeg($this->image);
} elseif( $image_type == IMAGETYPE_GIF ) {
imagegif($this->image);
} elseif( $image_type == IMAGETYPE_PNG ) {
imagepng($this->image);
}
}
function getWidth() {
return imagesx($this->image);
}
function getHeight() {
return imagesy($this->image);
}
#设置缩略图片高度
function resizeToHeight($height) {
$ratio = $height / $this->getHeight();
$width = $this->getWidth() * $ratio;
$this->resize($width,$height);
}
#设置缩略图片宽度
function resizeToWidth($width) {
$ratio = $width / $this->getWidth();
$height = $this->getheight() * $ratio;
$this->resize($width,$height);
}
function scale($scale) {
$width = $this->getWidth() * $scale/100;
$height = $this->getheight() * $scale/100;
$this->resize($width,$height);
}
function resize($width,$height) {
$new_image = imagecreatetruecolor($width, $height);
imagecopyresampled($new_image, $this->image, 0, 0, 0, 0, $width, $height, $this->getWidth(), $this->getHeight());
$this->image = $new_image;
}
}
?>
php imagecreate实例教程
描述
资源imagecreate（$width，$height）
imagecreate（）返回一个图像标识符代表了指定大小的空白图像。
我们建议使用imagecreatetruecolor（）。
看个
<?php
header("Content-type: image/png");
$im = @imagecreate(110, 20)
or die("Cannot Initialize new GD image stream");
$background_color = imagecolorallocate($im, 0, 0, 0);
$text_color = imagecolorallocate($im, 233, 14, 91);
imagestring($im, 1, 5, 5, "A Simple Text String", $text_color);
imagepng($im);
imagedestroy($im);
?>
如果您可以访问gd.h（很少在一个共享的主机），您可以修改GD_RESOLUTION并给它所需的价值。
该解决方案，我发现直接操纵的JPEG头字节。
我希望此示例代码将帮助别人，因为我花了5挖掘推测离开系统I小时，没有其他选择。
<?php
header('Content-Disposition: attachment; filename="myimg.jpg"');
header('Cache-Control: private');
$dst = imagecreatetruecolor(300, 300); /*this creates a 300x300 pixels image*/
ob_start(); /*don't send the output to the browser since we'll need to manipulate it*/
ImageJpeg($dst);
$img = ob_get_contents();
ob_end_clean();
//byte #14 in jpeg sets the resolution type: 0=none, 1=pixels per inch, 2=pixels per cm
//bytes 15-16 sets X resolution
//bytes 17-18 sets Y resolution
$img = substr_replace($img, pack('cnn',1,300,300),13,5);
echo $img;
?>
文件在其文件类型，并返回假的负载如果失败
<?php
function imagecreatefromfile($path, $user_functions = false)
{
$info = @getimagesize($path);
if(!$info)
{
return false;
}
$functions = array(
IMAGETYPE_GIF => 'imagecreatefromgif',
IMAGETYPE_JPEG => 'imagecreatefromjpeg',
IMAGETYPE_PNG => 'imagecreatefrompng',
IMAGETYPE_WBMP => 'imagecreatefromwbmp',
IMAGETYPE_XBM => 'imagecreatefromwxbm',
);
if($user_functions)
{
$functions[IMAGETYPE_BMP] = 'imagecreatefrombmp';
}
if(!$functions[$info[2]])
{
return false;
}
if(!function_exists($functions[$info[2]]))
{
return false;
}
return $functions[$info[2]]($path);
}
?>
php 验证码生成程序[可自动判断php gd库]
function ShowKey()
{
$key=strtolower(domake_password(4));
$set=esetcookie("checkkey",$key);
//是否支持gd库
if (function_exists("imagejpeg")) {
header ("Content-type: image/jpeg");
$img=imagecreate(69,20);
$black=imagecolorallocate($img,255,255,255);
$gray=imagecolorallocate($img,102,102,102);
imagefill($img,0,0,$gray);
imagestring($img,3,14,3,$key,$black);
imagejpeg($img);
imagedestroy($img);
}
elseif (function_exists("imagegif")) {
header ("Content-type: image/gif");
$img=imagecreate(69,20);
$black=imagecolorallocate($img,255,255,255);
$gray=imagecolorallocate($img,102,102,102);
imagefill($img,0,0,$gray);
imagestring($img,3,14,3,$key,$black);
imagegif($img);
imagedestroy($img);
}
elseif (function_exists("imagepng")) {
header ("Content-type: image/png");
$img=imagecreate(69,20);
$black=imagecolorallocate($img,255,255,255);
$gray=imagecolorallocate($img,102,102,102);
imagefill($img,0,0,$gray);
imagestring($img,3,14,3,$key,$black);
imagepng($img);
imagedestroy($img);
}
elseif (function_exists("imagewbmp")) {
header ("Content-type: image/vnd.wap.wbmp");
$img=imagecreate(69,20);
$black=imagecolorallocate($img,255,255,255);
$gray=imagecolorallocate($img,102,102,102);
imagefill($img,0,0,$gray);
imagestring($img,3,14,3,$key,$black);
imagewbmp($img);
imagedestroy($img);
}
else {
$set=esetcookie("checkkey","ebak");
@include("class/functions.php");
echo ReadFiletext("images/ebak.jpg");
}
}
ShowKey();
function displayimg($image)
{
$image = './upload/'.imgdecode($image);
//echo $image;exit;
if (file_exists($image))
{
$info = getimagesize($image);
header("Content-type:$info[mime]");
switch ($info[2])
{
case 1: $cimage = imagecreatefromgif($image);
imagegif($cimage);
imagedestroy($cimage);
break;
case 2: $cimage = imagecreatefromjpeg($image);
imagejpeg($cimage);
imagedestroy($cimage);
break;
case 3: $cimage = imagecreatefrompng($image);
imagepng($cimage);
imagedestroy($cimage);
break;
case 6: $cimage = imagecreatefromwbmp($image);
imagewbmp($cimage);
imagedestroy($cimage);
break;
}
echo $simage;
}
else
{
header("HTTP/1.0 404 Not Found");
}
}