imagecopyresampled对图像采样压缩jpg正常,png采样后变成0字节，系统也无法打开

imagecopyresampled对图像采样压缩jpg正常,png采样后变成0字节，系统也无法打开,代码如下：

 $width = 200;$height = 200;header("Content-Type: {$data['file_type']}");           /// [file_type] => image/pnglist($width_orig, $height_orig) = getimagesize(".{$data['full_file_path']}");   //图片路径$ratio_orig = $width_orig/$height_orig;if ($width/$height > $ratio_orig) {	 $width = $height*$ratio_orig;	} else {  $height = $width/$ratio_orig;	}				// 重新取样$image_p = imagecreatetruecolor($width, $height);$image = imagecreatefromjpeg(".{$data['full_file_path']}");$push = "image".$data['image_type'];imagecopyresampled($image_p, $image, 0, 0, 0, 0, $width, $height, $width_orig, $height_orig);$push($image_p, $data['min_im'], 100);imagedestroy($image_p); imagedestroy($image);

jpg格式图形采样后正常 ，唯独png 采样压缩有变成这样：

回复讨论(解决方案)

请贴全你的代码

第14行格式png时应该用imagecreatefrompng()
你的程序没做判断?

第14行格式png时应该用imagecreatefrompng()
你的程序没做判断?

不好意思，代码没有上最新的：

	//重新对图片采样,平滑插入像素值  	function upload_headimg($file='file') {				$path = getpath();		if(empty($path)){			return '';		}		$config['upload_path'] = $path;		$config['allowed_types'] = 'jpg|jpeg|gif|png';		$config['max_size'] = '10240';		$config['file_name'] = 'wj_'.time().mt_rand(1000, 9999);		$config['file_ext_tolower'] = TRUE;		$CI = &get_instance();		$CI->load->library('upload', $config);				$res =  $CI->upload->do_upload($file);		if($res){			$data = $CI->upload->data();			$path = ltrim($path,'.');			$data['full_file_path'] = $path.'/'.$data['file_name'];			$data['min_im'] = '.'.$path.'/min'.$data['file_name'];			$width = 200;			$height = 200;			header("Content-Type: {$data['file_type']}");			list($width_orig, $height_orig) = getimagesize(".{$data['full_file_path']}");			$ratio_orig = $width_orig/$height_orig;						if ($width/$height > $ratio_orig) {			   $width = $height*$ratio_orig;			} else {			   $height = $width/$ratio_orig;			}						// 重新取样			$image_p = imagecreatetruecolor($width, $height);			$create_im ="imagecreatefrom".$data['image_type'];			$image = $create_im(".{$data['full_file_path']}");			$push = "image".$data['image_type'];			imagecopyresampled($image_p, $image, 0, 0, 0, 0, $width, $height, $width_orig, $height_orig);			$push($image_p, $data['min_im'], 100);			imagedestroy($image_p);        	imagedestroy($image);			//exit;			return $data;											}else{			return $CI->upload->display_errors();		}		}

请贴全你的代码

	//重新对图片采样,平滑插入像素值  	function upload_headimg($file='file') {				$path = getpath();		if(empty($path)){			return '';		}		$config['upload_path'] = $path;		$config['allowed_types'] = 'jpg|jpeg|gif|png';		$config['max_size'] = '10240';		$config['file_name'] = 'wj_'.time().mt_rand(1000, 9999);		$config['file_ext_tolower'] = TRUE;		$CI = &get_instance();		$CI->load->library('upload', $config);				$res =  $CI->upload->do_upload($file);		if($res){			$data = $CI->upload->data();			$path = ltrim($path,'.');			$data['full_file_path'] = $path.'/'.$data['file_name'];			$data['min_im'] = '.'.$path.'/min'.$data['file_name'];			$width = 200;			$height = 200;			header("Content-Type: {$data['file_type']}");			list($width_orig, $height_orig) = getimagesize(".{$data['full_file_path']}");			$ratio_orig = $width_orig/$height_orig;						if ($width/$height > $ratio_orig) {			   $width = $height*$ratio_orig;			} else {			   $height = $width/$ratio_orig;			}						// 重新取样			$image_p = imagecreatetruecolor($width, $height);			$create_im ="imagecreatefrom".$data['image_type'];			$image = $create_im(".{$data['full_file_path']}");			$push = "image".$data['image_type'];			imagecopyresampled($image_p, $image, 0, 0, 0, 0, $width, $height, $width_orig, $height_orig);			$push($image_p, $data['min_im'], 100);			imagedestroy($image_p);        	imagedestroy($image);			//exit;			return $data;											}else{			return $CI->upload->display_errors();		}		}

找到原因了第40行
$push($image_p, $data['min_im'], 100);
第三个参数 函数为imagepng时范围为0-9
imagejpeg时范围为0-100

Regarding suggestions to rescale the 0-99 quality range of jpeg into the 0-9 range of png, note that for jpeg 99 is minimum compression (maximum quality) while for png 9 is maximum compression (quality doesn't change).

找到原因了第40行
$push($image_p, $data['min_im'], 100);
第三个参数 函数为imagepng时范围为0-9
imagejpeg时范围为0-100

谢谢您，这个问题已经解决了，请问能在保存压缩好的图片后不在浏览器输出吗？我只想直接返回数组，但却总是在浏览器里生成一个20X20的图形并停止运行下去

			// 重新取样			$image_p = imagecreatetruecolor($width, $height);			$create_im ="imagecreatefrom".$data['image_type'];			$image = $create_im(".{$data['full_file_path']}");			$push = "image".$data['image_type'];			imagecopyresampled($image_p, $image, 0, 0, 0, 0, $width, $height, $width_orig, $height_orig);			switch ($data['image_type']) {				case 'jpeg':					$status = $push($image_p, $data['min_im'], 100);					break;				case 'png':					$status = $push($image_p, $data['min_im'], 9);					break;				default:					$status = $push($image_p, $data['min_im']);					break;			}						imagedestroy($image_p);        	imagedestroy($image);			return $data;