php生成缩略图的两种方法（代码）

　　PHP是最近的热门语言，那么如果php要生成缩略图有什么办法呢？其实php生成缩略图有两种方法，核心代码如下，更多消息请关注应届毕业生网！　　public function getImage(){　　// create instance　　$basePath = base_path('public/');　　$md5 = 'b8c3bf0b10a81c5b6a98c527868a0000';$sub1 = substr($md5, 0, 1);$sub2 = substr($md5, 1, 2);　　$subPath = sprintf("image/%s/%s/%s%s.jpg", $sub1, $sub2, $md5, '300x300');$sourcePath = sprintf("image/%s/%s/%s.jpg", $sub1, $sub2, $md5);//截成100x80的缩略图//$image = $this->getCropper($basePath.$sourcePath,$basePath.$subPath, 300, 300);$image = $this->getCrops($basePath.$sourcePath,$basePath.$subPath, 300, 300);}　　//生成缩略图　　function getCropper($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);　　}　　//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);　　}