The perfect solution to low image quality caused by creating thumbnails with PHP_PHP Tutorial

I recently created a forum, and I need to have a ranking on the homepage, displaying a list of the top ten users with the most comments. There is a thumbnail image in the list of the latest works uploaded by the user. If I use the original image, the image will be too large and the homepage will load too slowly, so To use thumbnails
Using the imagecopyresized function above, the display quality is very poor, as shown in the figure

Later, I switched to imagecopyresampled and the effect was obviously changed as shown in the picture

Pay the complete code
[php]
/**
* @name thum Thumbnail function
* @param sting $img_name Image path
* @param int $max_width The maximum width of the thumbnail
* @param int $max_height The maximum height of the thumbnail
* @param sting $suffix thumbnail suffix (such as "img_x.jpg" represents a small picture, "img_m.jpg" represents a medium picture, "img_l.jpg" represents a large picture)
* @return void
*/
function thum($img_name,$max_width,$max_height,$suffix){
          $img_infos=getimagesize($img_name);
         $img_height=$img_infos[0];//Picture height
          $img_width=$img_infos[1];//Picture width
          $img_extension='';//Picture suffix name
         switch($img_infos[2]){
case 1:
                   $img_extension='gif';
break;
case 2:
                   $img_extension='jpeg';
break;
case 3:
                    $img_extension='png';
break;
                   default:
                   $img_extension='jpeg';
break;
                                                                                                                                                $new_img_size=get_thum_size($img_width,$img_height,$max_width,$max_height);//New image size
                                   
                                   
​​​​ //print_r($new_img_size);
           //die('test');
          $img_func='';//Function name
          $img_handle='';//Image handle
          $thum_handle='';//Thumbnail image handle
         switch($img_extension){
case 'jpg':
                     $img_handle=imagecreatefromjpeg($img_name);
                  $img_func='imagejpeg';
break;
case 'jpeg':
                     $img_handle=imagecreatefromjpeg($img_name);
                  $img_func='imagejpeg';
break;
case 'png':
                    $img_handle=imagecreatefrompng($img_name);
                   $img_func='imagepng';
break;
case 'gif':
                     $img_handle=imagecreatefromgif($img_name);
                   $img_func='imagegif';
break;
                   default:
                     $img_handle=imagecreatefromjpeg($img_name);
                  $img_func='imagejpeg';
break;
                                                                                                                                      /**
* @name get_thum_size Get the size of the thumbnail
* @param $width Image width
* @param $height picture height
* @param $max_width maximum width
* @param $maxHeight maximum height
* @param array $size;
/
         $quality=100;//Picture quality
If($img_func===='imagepng' && (str_replace('.', '', PHP_VERSION)>= 512)){//Processing of parameter changes for PHP versions greater than 5.12
               $quality=9;
                                                                                                 //
         $thum_handle=imagecreatetruecolor($new_img_size['height'],$new_img_size['width']);
If(function_exists('imagecopyresampled')){
                imagecopyresampled($thum_handle,$img_handle, 0, 0, 0, 0,$new_img_size['height'],$new_img_size['width'],$img_height,$img_width);
              }else{
                    imagecopyresized($thum_handle,$img_handle, 0, 0, 0, 0,$new_img_size['height'],$new_img_size['width'],$img_height,$img_width);
                                                                                                                                                call_user_func_array($img_func,array($thum_handle,get_thum_name($img_name,$suffix),$quality));
          imagedestroy($thum_handle);//Clear handle
          imagedestroy($img_handle);//Clear handle
}  

/
@name get_thum_size Get the size of the thumbnail
@param $width Image width
@param $height Image height
@param $max_width maximum width
@param $maxHeight maximum height
@param array $size;
/
function get_thum_size($width,$height,$max_width,$max_height){
$now_width=$width;//The current width
$now_height=$height;//The current height
$size=array();
If($now_width>$max_width){//If the current width is greater than the maximum width
          $now_height=number_format($max_width/$width,4);
         $now_width= $max_width;
         } 
If($now_height>$max_height){//If the current height is greater than the maximum height
         $now_width=number_format($max_height/$now_height,4);
          $now_height=$max_height;
         } 
$size['width']=floor($now_width);
$size['height']=floor($now_height);
Return $size;
}   / @ name get_thum_name Get the name of the thumbnail (add _x to the big picture)*/ www.2cto.com
function get_thum_name($img_name,$suffix){
          $str=explode('#',$img_name);
           $str1=explode('.',$str[1]);
           return $str[0].'_'.$suffix.'.'.$str1[1];
}  

http://www.bkjia.com/PHPjc/477906.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/477906.htmlTechArticleI will create a forum in the near future. There will be a ranking on the homepage to display a list of the top ten users with the most comments. List There is a thumbnail image of the latest work uploaded by the user. If you use the original image, the image has been...