Detailed explanation of the steps to dynamically crop images using PHP in nginx

/** * Author pony_chiang * 高性能图像裁剪方案 * 需要php-imagick扩展 */ ini_set ( "memory_limit", "80M" ); // 请求地址比如 http://yourdomain.com/resize.php?site=www&width=300&height=200&mode=2&path=uploadfile/helloworld.png // nginx重写规则 rewrite ^([^\.]*)/s/(.*)/(\d+)x(\d+)-(\d)/(.*) $1/s/resize.php?site=$2&width=$3&height=$4&mode=$5&path=$6 last; $path = trim ( $_GET ['path'] ); $mode = intval ( $_GET ['mode'] ); $site = trim ( $_GET ['site'] ); $width = intval ( $_GET ['width'] ); $height = intval ( $_GET ['height'] ); $site_list = array ('www' => '/mnt/webroot/test/' ); $orig_dir = dirname ( FILE ); if (! array_key_exists ( $site, $site_list )) { header ( 'HTTP/1.1 400 Bad Request' ); exit (); } if ($mode > 3 || $mode < 0) { header ( 'HTTP/1.1 400 Bad Request' ); exit (); } $orig_file = $site_list [$site] . $path; if (! file_exists ( $orig_file )) { header ( 'HTTP/1.1 404 Not Found' ); exit (); } $file_ext = '.' . pathinfo ( $path, PATHINFO_EXTENSION ); $file_name = basename ( $path, $file_ext ); $save_path = "{$orig_dir}/{$site}/{$width}x{$height}-{$mode}/{$path}"; $save_dir = dirname ( $save_path ); if (! file_exists ( $save_dir )) wpx_mkdir ( $save_dir ); $target_width = $width; $target_height = $height; $new_width = $target_width; $new_height = $target_height; $image = new Imagick ( $orig_file ); list ( $orig_width, $orig_height, $type, $attr ) = getimagesize ( $orig_file ); if ($mode == "0") { //等比缩放图像 $new_height = $orig_height * $new_width / $orig_width; if ($new_height > $target_height) { $new_width = $orig_width * $target_height / $orig_height; $new_height = $target_height; } } else if ($mode == "2") { // 放大并裁剪图像 $desired_aspect = $target_width / $target_height; $orig_aspect = $orig_width / $orig_height; if ($desired_aspect > $orig_aspect) { $trim = $orig_height - ($orig_width / $desired_aspect); $image->cropImage ( $orig_width, $orig_height - $trim, 0, $trim / 2 ); error_log ( "HEIGHT TRIM $trim" ); } else { $trim = $orig_width - ($orig_height * $desired_aspect); $image->cropImage ( $orig_width - $trim, $orig_height, $trim / 2, 0 ); } www.jbxue.com } $image->resizeImage ( $new_width, $new_height, imagick::FILTER_LANCZOS, 1 ); $image->writeImage ( $save_path ); header ( 'Content-Type: image/jpeg' ); header ( 'Last-Modified: ' . gmdate ( 'D, d M Y H:i:s' ) . ' GMT' ); echo file_get_contents ( $save_path ); return true; // 循环生成目录 function wpx_mkdir($dir, $mode = 0777) { if (is_dir ( $dir ) || @mkdir ( $dir, $mode )) return true; if (! wpx_mkdir ( dirname ( $dir ), $mode )) return false; return @mkdir ( $dir, $mode ); }

server { listen 80; server_name test.yourdomain.com; root /mnt/webroot/test; index index.php; expires 30d; location /s { #只有当没有生成这张图片时才调用动态裁剪 if (!-e $request_filename) { rewrite ^([^\.]*)/s/(.*)/(\d+)x(\d+)-(\d)/(.*) $1/s/resize.php?site=$2&width=$3&height=$4&mode=$5&path=$6 last; break; } } error_page 404 403 402 500 502 503 504 /404.html; location = /404.html { } location ~ \.php$ { fastcgi_pass 127.0.0.1:9000; fastcgi_index index.php; fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name; includefastcgi_params; } }

header('Last-Modified: ' .gmdate('D, d M Y H:i:s') . ' GMT' );