imagecopyresampled image sample Compression jpg Normal, PNG sample into 0 bytes, the system will not open

imagecopyresampled image sampling Compression jpg is normal, PNG sample becomes 0 bytes, the system can not be opened, the code is as follows:

$width = N, $height = 200;header ("Content-type: {$data [' File_type ']}");           [File_type] = image/pnglist ($width _orig, $height _orig) = GetImageSize (". { $data [' Full_file_path ']} ");   Picture path $ratio_orig = $width _orig/$height _orig;if ($width/$height > $ratio _orig) {$width = $height * $ratio _orig;} else {  $height = $width/$ratio _orig;} resampling $image_p = Imagecreatetruecolor ($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, $data [' Min_im '], Imagedestroy ($image _p); Imagedestroy ($image);

JPG format graphics are normal after sampling, but PNG sampling compression has changed to this:

Reply to discussion (solution)

Please post all your code.

The 14th row format PNG should use Imagecreatefrompng ()
Your program didn't make a judgment?

The 14th row format PNG should use Imagecreatefrompng ()
Your program didn't make a judgment?

Sorry, the code is not up to date:

Resample picture, smooth insert pixel value 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 (+ 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 = €; $height = 200;header ("Content-type: {$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 = $heig ht* $ratio _orig;} else {$height = $width/$ratio _orig;} resampling $image_p = Imagecreatetruecolor ($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, $data [' Min_im '], Imagedestroy ($image _p); Imagedestroy ($image);//exit;return $data;} Else{return $CI->upload->display_errors ();}}

Please post all your code.

Resample picture, smooth insert pixel value 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 (+ 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 = €; $height = 200;header ("Content-type: {$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 = $heig ht* $ratio _orig;} else {$height = $width/$ratio _orig;} resampling $image_p = Imagecreatetruecolor ($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, $data [' Min_im '], Imagedestroy ($image _p); Imagedestroy ($image);//exit;return $data;} Else{return $CI->upload->display_errors ();}}

I found the reason. Line 40th
$push ($image _p, $data [' min_im '], 100);
The third parameter function is imagepng with a range of 0-9
Imagejpeg Time range of 0-100

Regarding suggestions to rescale the 0-99 quality range of JPEG into the 0-9 range of PNG, note this for JPEG are Minimu M compression (maximum quality) while for PNG 9 are maximum compression (quality doesn ' t change).

I found the reason. Line 40th
$push ($image _p, $data [' min_im '], 100);
The third parameter function is imagepng with a range of 0-9
Imagejpeg Time range of 0-100

Thank you, this problem has been solved, can I save the compressed picture after the browser output? I just want to return the array directly, but I always generate a 20x20 graphic in my browser and stop running.

resampling $image_p = Imagecreatetruecolor ($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 '], 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;

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