PHP生成缩略图，相信很多人都实现过吧，没有的友友也看看吧。最近在坐一个生成缩略图的功能，还要要求上传的图片没有和限制的宽高的话，自动补白边，以下是自己实践过的例子，和大家分享一下，我主要用的还是laravel框架的，以下方法适用其他的框架，原生的也是可以的。其实懂PHP的友友，用在哪里都是可以的
$source_path:原图的路径
$NewImagePath:生成缩略图路径
$target_width:缩略图宽度
$target_height:缩略图高度
<?php function getCropper($source_path,$NewImagePath, $target_width, $target_height) { $source_info = getimagesize($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 / $target_width; // 源图过高 if ($source_ratio > $target_ratio) { $cropped_width = $source_width; $cropped_height = $source_width * $target_ratio; $source_x = 0; $source_y = ($source_height - $cropped_height) / 2; } // 源图过宽 elseif ($source_ratio < $target_ratio) { $cropped_width = $source_height / $target_ratio; $cropped_height = $source_height; $source_x = ($source_width - $cropped_width) / 2; $source_y = 0; } // 源图适中 else { $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, $cropped_height); // 图片裁剪 imagecopy($cropped_image, $source_image, 0, 0, $source_x, $source_y, $cropped_width, $cropped_height); // 图片缩放 imagecopyresampled($target_image, $cropped_image, 0, 0, 0, 0, $target_width, $target_height, $cropped_width, $cropped_height); header('Content-Type: image/jpeg'); imagejpeg($target_image,$NewImagePath,100); imagedestroy($source_image); imagedestroy($target_image); imagedestroy($cropped_image); }
以下方法是生成缩略图，填充白边的方法
<?php //生成缩略图，填充白边 function getCrops($src_path,$NewImagePath,$width,$height){ //源图对象 $src_image = imagecreatefromstring(file_get_contents($src_path)); $source_info = getimagesize($src_path); $source_mime = $source_info['mime']; $src_width = imagesx($src_image); $src_height = imagesy($src_image); switch ($source_mime) { case 'image/gif': $src_image = imagecreatefromgif($src_path); break; case 'image/jpeg': $src_image = imagecreatefromjpeg($src_path); break; case 'image/png': $src_image = imagecreatefrompng($src_path); break; default: return false; break; } //生成等比例的缩略图 //$tmp_image_width = 0; //$tmp_image_height = 0; if ($src_width / $src_height >= $width / $height) { $tmp_image_width = $width; $tmp_image_height = round($tmp_image_width * $src_height / $src_width); } else { $tmp_image_height = $height; $tmp_image_width = round($tmp_image_height * $src_width / $src_height); } $tmpImage = imagecreatetruecolor($tmp_image_width, $tmp_image_height); imagecopyresampled($tmpImage, $src_image, 0, 0, 0, 0, $tmp_image_width, $tmp_image_height, $src_width, $src_height); //添加白边 $final_image = imagecreatetruecolor($width, $height); $color = imagecolorallocate($final_image, 255, 255, 255); imagefill($final_image, 0, 0, $color); $x = round(($width - $tmp_image_width) / 2); $y = round(($height - $tmp_image_height) / 2); imagecopy($final_image, $tmpImage, $x, $y, 0, 0, $tmp_image_width, $tmp_image_height); //输出图片 header('Content-Type: image/jpeg'); imagejpeg($final_image,$NewImagePath,100); imagedestroy($src_image); imagedestroy($final_image); }
