How to upload images and compress them in PHP, _PHP tutorial

The implementation method of uploading images and compressing them in PHP,

This article explains the implementation method of uploading images and compressing them in PHP. The previous article "PHP Implementing Image Uploading and Compression" has been Everyone gave a brief introduction. This time, you can upload an image and then thumbnail it according to the proportion, specifying the maximum height or maximum width of the thumbnail. The specific content is as follows

Implementation code:

<&#63;php  
function _UPLOADPIC($upfile, $maxsize, $updir, $newname = 'date') {  
   
 if ($newname == 'date')  
  $newname = date ( "Ymdhis" ); //使用日期做文件名  
 $name = $upfile ["name"];  
 $type = $upfile ["type"];  
 $size = $upfile ["size"];  
 $tmp_name = $upfile ["tmp_name"];  
   
 switch ($type) {  
  case 'image/pjpeg' :  
  case 'image/jpeg' :  
   $extend = ".jpg";  
   break;  
  case 'image/gif' :  
   $extend = ".gif";  
   break;  
  case 'image/png' :  
   $extend = ".png";  
   break;  
 }  
 if (emptyempty ( $extend )) {  
  echo ( "警告！只能上传图片类型：GIF JPG PNG" );  
  exit ();  
 }  
 if ($size > $maxsize) {  
  $maxpr = $maxsize / 1000;  
  echo ( "警告！上传图片大小不能超过" . $maxpr . "K!" );  
  exit ();  
 }  
 if (move_uploaded_file ( $tmp_name, $updir . $newname . $extend )) {  
  return $updir . $newname . $extend;  
 }  
}  
 
function show_pic_scal($width, $height, $picpath) {  
 $imginfo = GetImageSize ( $picpath );  
 $imgw = $imginfo [0];  
 $imgh = $imginfo [1];  
   
 $ra = number_format ( ($imgw / $imgh), 1 ); //宽高比  
 $ra2 = number_format ( ($imgh / $imgw), 1 ); //高宽比  
   
 
 if ($imgw > $width or $imgh > $height) {  
  if ($imgw > $imgh) {  
   $newWidth = $width;  
   $newHeight = round ( $newWidth / $ra );  
    
  } elseif ($imgw < $imgh) {  
   $newHeight = $height;  
   $newWidth = round ( $newHeight / $ra2 );  
  } else {  
   $newWidth = $width;  
   $newHeight = round ( $newWidth / $ra );  
  }  
 } else {  
  $newHeight = $imgh;  
  $newWidth = $imgw;  
 }  
 $newsize [0] = $newWidth;  
 $newsize [1] = $newHeight;  
   
 return $newsize;  
}  
 
 
 
function getImageInfo($src)  
{  
 return getimagesize($src);  
}  
/** 
* 创建图片，返回资源类型 
* @param string $src 图片路径 
* @return resource $im 返回资源类型 
* **/ 
function create($src)  
{  
 $info=getImageInfo($src);  
 switch ($info[2])  
 {  
  case 1:  
   $im=imagecreatefromgif($src);  
   break;  
  case 2:  
   $im=imagecreatefromjpeg($src);  
   break;  
  case 3:  
   $im=imagecreatefrompng($src);  
   break;  
 }  
 return $im;  
}  
/** 
* 缩略图主函数 
* @param string $src 图片路径 
* @param int $w 缩略图宽度 
* @param int $h 缩略图高度 
* @return mixed 返回缩略图路径 
* **/ 
 
function resize($src,$w,$h)  
{  
 $temp=pathinfo($src);  
 $name=$temp["basename"];//文件名  
 $dir=$temp["dirname"];//文件所在的文件夹  
 $extension=$temp["extension"];//文件扩展名  
 $savepath="{$dir}/{$name}";//缩略图保存路径,新的文件名为*.thumb.jpg  
 
 //获取图片的基本信息  
 $info=getImageInfo($src);  
 $width=$info[0];//获取图片宽度  
 $height=$info[1];//获取图片高度  
 $per1=round($width/$height,2);//计算原图长宽比  
 $per2=round($w/$h,2);//计算缩略图长宽比  
 
 //计算缩放比例  
 if($per1>$per2||$per1==$per2)  
 {  
  //原图长宽比大于或者等于缩略图长宽比，则按照宽度优先  
  $per=$w/$width;  
 }  
 if($per1<$per2)  
 {  
  //原图长宽比小于缩略图长宽比，则按照高度优先  
  $per=$h/$height;  
 }  
 $temp_w=intval($width*$per);//计算原图缩放后的宽度  
 $temp_h=intval($height*$per);//计算原图缩放后的高度  
 $temp_img=imagecreatetruecolor($temp_w,$temp_h);//创建画布  
 $im=create($src);  
 imagecopyresampled($temp_img,$im,0,0,0,0,$temp_w,$temp_h,$width,$height);  
 if($per1>$per2)  
 {  
  imagejpeg($temp_img,$savepath, 100);  
  imagedestroy($im);  
  return addBg($savepath,$w,$h,"w");  
  //宽度优先，在缩放之后高度不足的情况下补上背景  
 }  
 if($per1==$per2)  
 {  
  imagejpeg($temp_img,$savepath, 100);  
  imagedestroy($im);  
  return $savepath;  
  //等比缩放  
 }  
 if($per1<$per2)  
 {  
  imagejpeg($temp_img,$savepath, 100);  
  imagedestroy($im);  
  return addBg($savepath,$w,$h,"h");  
  //高度优先，在缩放之后宽度不足的情况下补上背景  
 }  
}  
/** 
* 添加背景 
* @param string $src 图片路径 
* @param int $w 背景图像宽度 
* @param int $h 背景图像高度 
* @param String $first 决定图像最终位置的，w 宽度优先 h 高度优先 wh:等比 
* @return 返回加上背景的图片 
* **/ 
function addBg($src,$w,$h,$fisrt="w")  
{  
 $bg=imagecreatetruecolor($w,$h);  
 $white = imagecolorallocate($bg,255,255,255);  
 imagefill($bg,0,0,$white);//填充背景  
 
 //获取目标图片信息  
 $info=getImageInfo($src);  
 $width=$info[0];//目标图片宽度  
 $height=$info[1];//目标图片高度  
 $img=create($src);  
 if($fisrt=="wh")  
 {  
  //等比缩放  
  return $src;  
 }  
 else 
 {  
  if($fisrt=="w")  
  {  
   $x=0;  
   $y=($h-$height)/2;//垂直居中  
  }  
  if($fisrt=="h")  
  {  
   $x=($w-$width)/2;//水平居中  
   $y=0;  
  }  
  imagecopymerge($bg,$img,$x,$y,0,0,$width,$height,100);  
  imagejpeg($bg,$src,100);  
  imagedestroy($bg);  
  imagedestroy($img);  
  return $src;  
 }  
 
}  
 
 
&#63;>

How to use:

$filename=(_UPLOADPIC($_FILES["upload"],$maxsize,$updir,$newname='date')); 
  $show_pic_scal=show_pic_scal(230, 230, $filename); 
  resize($filename,$show_pic_scal[0],$show_pic_scal[1]); 

I hope this article will help you learn PHP programming.

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