PHP实现图片压缩的两则实例_php技巧
本文介绍了PHP实现图片压缩的两种方法，读者可以根据具体应用参考或加以改进，以适应自身应用需求！废话不多说，主要代码部分如下：
实例1：
<?php
/**
* desription 压缩图片
* @param sting $imgsrc 图片路径
* @param string $imgdst 压缩后保存路径
*/
function image_png_size_add($imgsrc,$imgdst){
list($width,$height,$type)=getimagesize($imgsrc);
$new_width = ($width>600?600:$width)*0.9;
$new_height =($height>600?600:$height)*0.9;
switch($type){
case 1:
$giftype=check_gifcartoon($imgsrc);
if($giftype){
header('Content-Type:image/gif');
$image_wp=imagecreatetruecolor($new_width, $new_height);
$image = imagecreatefromgif($imgsrc);
imagecopyresampled($image_wp, $image, 0, 0, 0, 0, $new_width, $new_height, $width, $height);
imagejpeg($image_wp, $imgdst,75);
imagedestroy($image_wp);
}
break;
case 2:
header('Content-Type:image/jpeg');
$image_wp=imagecreatetruecolor($new_width, $new_height);
$image = imagecreatefromjpeg($imgsrc);
imagecopyresampled($image_wp, $image, 0, 0, 0, 0, $new_width, $new_height, $width, $height);
imagejpeg($image_wp, $imgdst,75);
imagedestroy($image_wp);
break;
case 3:
header('Content-Type:image/png');
$image_wp=imagecreatetruecolor($new_width, $new_height);
$image = imagecreatefrompng($imgsrc);
imagecopyresampled($image_wp, $image, 0, 0, 0, 0, $new_width, $new_height, $width, $height);
imagejpeg($image_wp, $imgdst,75);
imagedestroy($image_wp);
break;
}
}
/**
* desription 判断是否gif动画
* @param sting $image_file图片路径
* @return boolean t 是 f 否
*/
function check_gifcartoon($image_file){
$fp = fopen($image_file,'rb');
$image_head = fread($fp,1024);
fclose($fp);
return preg_match("/".chr(0x21).chr(0xff).chr(0x0b).'NETSCAPE2.0'."/",$image_head)?false:true;
}
?>
实例2：
<?php
/*
----------------------------------------------------------------------
函数:调整图片尺寸或生成缩略图
返回:True/False
参数:
$Image 需要调整的图片(含路径)
$Dw=450 调整时最大宽度;缩略图时的绝对宽度
$Dh=450 调整时最大高度;缩略图时的绝对高度
$Type=1 1,调整尺寸; 2,生成缩略图
$path='img/';//路径
$phtypes=array(
'img/gif',
'img/jpg',
'img/jpeg',
'img/bmp',
'img/pjpeg',
'img/x-png'
);
Function Img($Image,$Dw=450,$Dh=450,$Type=1){
IF(!File_Exists($Image)){
Return False;
}
//如果需要生成缩略图,则将原图拷贝一下重新给$Image赋值
IF($Type!=1){
Copy($Image,Str_Replace(".","_x.",$Image));
$Image=Str_Replace(".","_x.",$Image);
}
//取得文件的类型,根据不同的类型建立不同的对象
$ImgInfo=GetImageSize($Image);
Switch($ImgInfo[2]){
Case 1:
$Img = @ImageCreateFromGIF($Image);
Break;
Case 2:
$Img = @ImageCreateFromJPEG($Image);
Break;
Case 3:
$Img = @ImageCreateFromPNG($Image);
Break;
}
//如果对象没有创建成功,则说明非图片文件
IF(Empty($Img)){
//如果是生成缩略图的时候出错,则需要删掉已经复制的文件
IF($Type!=1){Unlink($Image);}
Return False;
}
//如果是执行调整尺寸操作则
IF($Type==1){
$w=ImagesX($Img);
$h=ImagesY($Img);
$width = $w;
$height = $h;
IF($width>$Dw){
$Par=$Dw/$width;
$width=$Dw;
$height=$height*$Par;
IF($height>$Dh){
$Par=$Dh/$height;
$height=$Dh;
$width=$width*$Par;
}
}ElseIF($height>$Dh){
$Par=$Dh/$height;
$height=$Dh;
$width=$width*$Par;
IF($width>$Dw){
$Par=$Dw/$width;
$width=$Dw;
$height=$height*$Par;
}
}Else{
$width=$width;
$height=$height;
}
$nImg = ImageCreateTrueColor($width,$height); //新建一个真彩色画布
ImageCopyReSampled($nImg,$Img,0,0,0,0,$width,$height,$w,$h);//重采样拷贝部分图像并调整大小
ImageJpeg ($nImg,$Image); //以JPEG格式将图像输出到浏览器或文件
Return True;
//如果是执行生成缩略图操作则
}Else{
$w=ImagesX($Img);
$h=ImagesY($Img);
$width = $w;
$height = $h;
$nImg = ImageCreateTrueColor($Dw,$Dh);
IF($h/$w>$Dh/$Dw){ //高比较大
$width=$Dw;
$height=$h*$Dw/$w;
$IntNH=$height-$Dh;
ImageCopyReSampled($nImg, $Img, 0, -$IntNH/1.8, 0, 0, $Dw, $height, $w, $h);
}Else{ //宽比较大
$height=$Dh;
$width=$w*$Dh/$h;
$IntNW=$width-$Dw;
ImageCopyReSampled($nImg, $Img, -$IntNW/1.8, 0, 0, 0, $width, $Dh, $w, $h);
}
ImageJpeg ($nImg,$Image);
Return True;
}
}
?>
<html><body>
<form method="post" enctype="multipart/form-data" name="form1">
<table>
<tr><td>上传图片</td></tr>
<tr><td><input type="file" name="photo" size="20" /></td></tr>
<tr><td><input type="submit" value="上传"/></td></tr>
</table>
允许上传的文件类型为:<?=implode(', ',$phtypes)?></form>
<?php
if($_SERVER['REQUEST_METHOD']=='POST'){
if (!is_uploaded_file($_FILES["photo"][tmp_name])){
echo "图片不存在";
exit();
}
if(!is_dir('img')){//路径若不存在则创建
mkdir('img');
}
$upfile=$_FILES["photo"];
$pinfo=pathinfo($upfile["name"]);
$name=$pinfo['basename'];//文件名
$tmp_name=$upfile["tmp_name"];
$file_type=$pinfo['extension'];//获得文件类型
$showphpath=$path.$name;
if(in_array($upfile["type"],$phtypes)){
echo "文件类型不符！";
exit();
}
if(move_uploaded_file($tmp_name,$path.$name)){
echo "成功！";
Img($showphpath,100,800,2);
}
echo "<img src=\"".$showphpath."\" / alt="PHP实现图片压缩的两则实例_php技巧" >";
}
?>
</body>
</html>
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
1665
14
1423
52
1321
25
1269
29
1249
24
PHP and Python: Comparing Two Popular Programming Languages
Apr 14, 2025 am 12:13 AM
PHP and Python each have their own advantages, and choose according to project requirements. 1.PHP is suitable for web development, especially for rapid development and maintenance of websites. 2. Python is suitable for data science, machine learning and artificial intelligence, with concise syntax and suitable for beginners.
PHP in Action: Real-World Examples and Applications
Apr 14, 2025 am 12:19 AM
PHP is widely used in e-commerce, content management systems and API development. 1) E-commerce: used for shopping cart function and payment processing. 2) Content management system: used for dynamic content generation and user management. 3) API development: used for RESTful API development and API security. Through performance optimization and best practices, the efficiency and maintainability of PHP applications are improved.
PHP: A Key Language for Web Development
Apr 13, 2025 am 12:08 AM
PHP is a scripting language widely used on the server side, especially suitable for web development. 1.PHP can embed HTML, process HTTP requests and responses, and supports a variety of databases. 2.PHP is used to generate dynamic web content, process form data, access databases, etc., with strong community support and open source resources. 3. PHP is an interpreted language, and the execution process includes lexical analysis, grammatical analysis, compilation and execution. 4.PHP can be combined with MySQL for advanced applications such as user registration systems. 5. When debugging PHP, you can use functions such as error_reporting() and var_dump(). 6. Optimize PHP code to use caching mechanisms, optimize database queries and use built-in functions. 7
The Enduring Relevance of PHP: Is It Still Alive?
Apr 14, 2025 am 12:12 AM
PHP is still dynamic and still occupies an important position in the field of modern programming. 1) PHP's simplicity and powerful community support make it widely used in web development; 2) Its flexibility and stability make it outstanding in handling web forms, database operations and file processing; 3) PHP is constantly evolving and optimizing, suitable for beginners and experienced developers.
PHP vs. Python: Understanding the Differences
Apr 11, 2025 am 12:15 AM
PHP and Python each have their own advantages, and the choice should be based on project requirements. 1.PHP is suitable for web development, with simple syntax and high execution efficiency. 2. Python is suitable for data science and machine learning, with concise syntax and rich libraries.
PHP and Python: Code Examples and Comparison
Apr 15, 2025 am 12:07 AM
PHP and Python have their own advantages and disadvantages, and the choice depends on project needs and personal preferences. 1.PHP is suitable for rapid development and maintenance of large-scale web applications. 2. Python dominates the field of data science and machine learning.
PHP vs. Other Languages: A Comparison
Apr 13, 2025 am 12:19 AM
PHP is suitable for web development, especially in rapid development and processing dynamic content, but is not good at data science and enterprise-level applications. Compared with Python, PHP has more advantages in web development, but is not as good as Python in the field of data science; compared with Java, PHP performs worse in enterprise-level applications, but is more flexible in web development; compared with JavaScript, PHP is more concise in back-end development, but is not as good as JavaScript in front-end development.
PHP and Python: Different Paradigms Explained
Apr 18, 2025 am 12:26 AM
PHP is mainly procedural programming, but also supports object-oriented programming (OOP); Python supports a variety of paradigms, including OOP, functional and procedural programming. PHP is suitable for web development, and Python is suitable for a variety of applications such as data analysis and machine learning.
