PHP 图片操作（按照指定尺寸压缩，按照比例裁剪）

 ??/** ????* 按照指定的尺寸压缩图片 ????* @param $source_path ?原图路径 ????* @param $target_path ?保存路径 ????* @param $imgWidth ????目标宽度 ????* @param $imgHeight ???目标高度 ????* @return bool|string ????*/ ???function resize_image($source_path,$target_path,$imgWidth,$imgHeight) ???{ ???????$source_info = getimagesize($source_path); ???????$source_mime = $source_info[‘mime‘]; ???????switch ($source_mime) ???????{ ???????????case ‘image/gif‘: ???????????????$source_image = imagecreatefromgif($source_path); ???????????????break; ???????????case ‘image/jpeg‘: ???????????????$source_image = imagecreatefromjpeg($source_path); ???????????????break; ???????????case ‘image/png‘: ???????????????$source_image = imagecreatefrompng($source_path); ???????????????break; ???????????default: ???????????????return false; ???????????????break; ???????} ???????$target_image ????= imagecreatetruecolor($imgWidth, $imgHeight); //创建一个彩色的底图 ???????imagecopyresampled($target_image, $source_image, 0, 0, 0, 0, $imgWidth, $imgHeight, $source_info[0], $source_info[1]); ???????//保存图片到本地 ???????$dir = ‘../‘.$target_path. ‘/‘. date("Ymd") . ‘/‘; ???????if (!is_dir($dir)) { ???????????mkdir($dir, 0777); ???????} ???????$fileName = $dir.date("YmdHis").uniqid().‘.jpg‘; ???????if(!imagejpeg($target_image,‘./‘.$fileName)){ ???????????$fileName = ‘‘; ???????} ???????imagedestroy($target_image); ???????return $fileName; ???}

/** ????* 图像裁剪 ????* @param $title string 原图路径 ????* @param $content string 需要裁剪的宽 ????* @param $encode string 需要裁剪的高 ????* @param $target_path string 需要保存的路径 ????*/ ???function image_cropper($source_path, $target_width, $target_height, $target_path) ???{ ???????$source_info ????= getimagesize($source_path); ???????$source_width ????= $source_info[0]; ???????$source_height ????= $source_info[1]; ???????$source_mime ????= $source_info[‘mime‘]; ???????$source_ratio ????= $source_height / $source_width; ???????$target_ratio ????= $target_height / $target_width; ???????if ($source_ratio > $target_ratio) // 源图过高 ???????{ ???????????$cropped_width = $source_width; ???????????$cropped_height = $source_width * $target_ratio; ???????????$source_x = 0; ???????????$source_y = ($source_height - $cropped_height) / 2; ???????}elseif ($source_ratio < $target_ratio){ ?// 源图过宽 ???????????$cropped_width = $source_height / $target_ratio; ???????????$cropped_height = $source_height; ???????????$source_x = ($source_width - $cropped_width) / 2; ???????????$source_y = 0; ???????}else{ // 源图适中 ???????????$cropped_width = $source_width; ???????????$cropped_height = $source_height; ???????????$source_x = 0; ???????????$source_y = 0; ???????} ???????switch ($source_mime) ???????{ ???????????case ‘image/gif‘: ???????????????$source_image = imagecreatefromgif($source_path); ???????????????break; ???????????case ‘image/jpeg‘: ???????????????$source_image = imagecreatefromjpeg($source_path); ???????????????break; ???????????case ‘image/png‘: ???????????????$source_image = imagecreatefrompng($source_path); ???????????????break; ???????????default: ???????????????return false; ???????????????break; ???????} ???????$target_image = imagecreatetruecolor($target_width, $target_height); ???????$cropped_image = imagecreatetruecolor($cropped_width, $cropped_height); ???????// 裁剪 ???????imagecopy($cropped_image, $source_image, 0, 0, $source_x, $source_y, $cropped_width, $cropped_height); ???????// 缩放 ???????imagecopyresampled($target_image, $cropped_image, 0, 0, 0, 0, $target_width, $target_height, $cropped_width, $cropped_height); ???????//保存图片到本地(两者选一) ???????$dir = ‘../../‘.$target_path. ‘/‘. date("Ymd") . ‘/‘; ???????if (!is_dir($dir)) { ???????????mkdir($dir, 0777); ???????} ???????$fileName = $dir.date("YmdHis").uniqid().‘.jpg‘; ???????if(!imagejpeg($target_image,‘./‘.$fileName)){ ???????????$fileName = ‘‘; ???????} ???????imagedestroy($target_image); ???????return $fileName; ???}