Unable to create thumb, image is black

Question

Am uploading Multiple image from single input and create thumb form all uploaded image on fly But when i run code i get only black image but orginal image is same as uploaded

    <?php

$newname = md5(rand() * time());
$file1 = isset($_FILES['files']['name'][0]) ? $_FILES['files']['name'][0] : null;
$file2 = isset($_FILES['files']['name'][1]) ? $_FILES['files']['name'][1] : null;
$file3 = isset($_FILES['files']['name'][2]) ? $_FILES['files']['name'][2] : null;
$file4 = isset($_FILES['files']['name'][3]) ? $_FILES['files']['name'][3] : null;
$file5 = isset($_FILES['files']['name'][4]) ? $_FILES['files']['name'][4] : null;
if (isset($_FILES['files'])) {
    $errors = array();
    foreach ($_FILES['files']['tmp_name'] as $key => $tmp_name) {
        $file_name = $key . $_FILES['files']['name'][$key];
        $file_size = $_FILES['files']['size'][$key];
        $file_tmp = $_FILES['files']['tmp_name'][$key];
        $file_type = $_FILES['files']['type'][$key];
        if ($file_size > 2097152000) {
            $errors[] = 'File size must be less than 2 MB';
        }
        $desired_dir = "user_data/";
        if (empty($errors) == true) {
            if (is_dir($desired_dir) == false) {
                mkdir("$desired_dir", 0700);        // Create directory if it does not exist
            }
            if (is_dir("$desired_dir/" . $file_name) == false) {
                move_uploaded_file($file_tmp, "$desired_dir/" . $newname . $file_name);
            } else {                                  // rename the file if another one exist
                $new_dir = "$desired_dir/" . $newname . $file_name;
                rename($file_tmp, $new_dir);
            }
        } else {
            print_r($errors);
        }
    }
    if (empty($error)) {
        echo "FILE : $file1<br>";
        echo "FILE : $file2<br>";
        echo "FILE : $file3<br>";
        echo "FILE : $file4<br>";
        echo "FILE : $file5<br>";
    }
}
$orig_directory = "$desired_dir";    //Full image folder
$thumb_directory =  "thumb/";    //Thumbnail folder

/* Opening the thumbnail directory and looping through all the thumbs: */
$dir_handle = @opendir($orig_directory); //Open Full image dirrectory
if ($dir_handle > 1){ //Check to make sure the folder opened

$allowed_types=array('jpg','jpeg','gif','png');
$file_type=array();
$ext='';
$title='';
$i=0;

while ($file_name = @readdir($dir_handle)) {
    /* Skipping the system files: */
    if($file_name=='.' || $file_name == '..') continue;

    $file_type = explode('.',$file_name);    //This gets the file name of the images
    $ext = strtolower(array_pop($file_type));

    /* Using the file name (withouth the extension) as a image title: */
    $title = implode('.',$file_type);
    $title = htmlspecialchars($title);

    /* If the file extension is allowed: */
    if(in_array($ext,$allowed_types)) {

        /* If you would like to inpute images into a database, do your mysql query here */

        /* The code past here is the code at the start of the tutorial */
        /* Outputting each image: */

        $nw = 100;
        $nh = 100;
        $source = "$desired_dir{$file_name}";
        $stype = explode(".", $source);
        $stype = $stype[count($stype)-1];
        $dest = "thumb/{$file_name}";

        $size = getimagesize($source);
        $w = $size[0];
        $h = $size[1];

        switch($stype) {
            case 'gif':
                $simg = imagecreatefromgif($source);
                break;
            case 'jpg': 
                $simg = imagecreatefromjpeg($source);
                break;
            case 'png':
                $simg = imagecreatefrompng($source);
                break;
        }

        $dimg = imagecreatetruecolor($nw, $nh);
        $wm = $w/$nw;
        $hm = $h/$nw;
        $h_height = $nh/2;
        $w_height = $nw/2;

        if($w> $h) {
            $adjusted_width = $w / $hm;
            $half_width = $adjusted_width / 2;
            $int_width = $w / $hm;
            imagecopyresampled($dimg,$simg,-$int_width,0,0,0,$adjusted_width,$nh,$w,$h);
        } else {
            imagecopyresampled($dimg,$simg,0,0,0,0,$nw,$nh,$w,$h);
        }
            imagejpeg($dimg,$dest,100);
        }
}

/* Closing the directory */
@closedir($dir_handle);

}
?>

When i run code this how am getting out put file, don't know whats going on can some one help me find the error Black thumb is created for all type image formate

When i remove the following code from above code it works what does this code does

if($w> $h) {
        $adjusted_width = $w / $hm;
        $half_width = $adjusted_width / 2;
        $int_width = $w / $hm;
        imagecopyresampled($dimg,$simg,-$int_width,0,0,0,0,$adjusted_width,$nw,$nh,$w,$h);
    } else 

Answer 1

I think it's better to go for the mime type than the extension.

You'll do this:

function check_supported_type($type)
{
    switch($type)
    {
        case "image/jpeg":
        case "image/gif":
        case "image/png":
            return true;
        default:
            return false;
    }
}

function GetMimeType($file)
{
    //$type = mime_content_type($file); //deprecated

    /* //file info -> normal method, but returns wrong values for ics files..
    $finfo = finfo_open(FILEINFO_MIME_TYPE); // return mime type ala mimetype extension
    $type = $filename.":".finfo_file($finfo, $filename);
    finfo_close($finfo);
    */

    $forbiddenChars = array('?', '*', ':', '|', ';', '<', '>');

    if(strlen(str_replace($forbiddenChars, '', $file)) < strlen($file))
        throw new \ArgumentException("Forbidden characters!");

    $file = escapeshellarg($file);

    ob_start();
    $type = system("file --mime-type -b ".$file);
    ob_clean();

    return $type;
}

use it like this:

$file = "someimage.jpg";
$mime = GetMimeType($file);
if(check_supported_type($mime))
{
   //do your image processing
}

hope this helps

EDIT:

Maybe you can take a look at my other answer: https://stackoverflow.com/a/26981319/3641016 there you'll see how to generate thumbs.

EDIT:

added the answer to your editet question:

replace:

$wm = $w/$nw;
$hm = $h/$nw;
$h_height = $nh/2;
$w_height = $nw/2;

if($w> $h) {
    $adjusted_width = $w / $hm;
    $half_width = $adjusted_width / 2;
    $int_width = $w / $hm;
    imagecopyresampled($dimg,$simg,-$int_width,0,0,0,$adjusted_width,$nh,$w,$h);
} else {
    imagecopyresampled($dimg,$simg,0,0,0,0,$nw,$nh,$w,$h);
}

with:

if($w > $h)
{
    imagecopyresampled($dimg, $simg, 0,0, ($nw / $h * $w / 2 - $nw / 2),0, $nw,$nw, $h,$h);
}
else
{
    imagecopyresampled($dimg, $simg, 0,0, 0,($nw / $w * $h / 2 - $nw / 2), $nw,$nw, $w,$w);
}

and everything should be ok. (if the thumb is quadratic)

Answer 2

This is my code for uploading multiple files and cropping and cropping them.

It uploads the image to a folder, then picks the image, crops it , re-uploads the cropped image and deletes the original image.

Am sure you can play around with this

This is the php code

if(isset($_POST['upload_gal']))
{

$fk_id = $_POST['fk_id'];


$errors= array();
foreach($_FILES['files']['tmp_name'] as $key => $tmp_name ){
    $file_name = $key.$_FILES['files']['name'][$key];
    $file_size =$_FILES['files']['size'][$key];
    $file_tmp =$_FILES['files']['tmp_name'][$key];
    $file_type=$_FILES['files']['type'][$key];


   if($file_type=='image/jpeg'||$type=='image/gif'||$type=='image/bmp'||$type=='image/png')
             {
    $image_info = getimagesize($_FILES["files"]["tmp_name"][$key]);
    $image_width = $image_info[0];
    $image_height = $image_info[1];

                 $desired_dir="brand_images/";

    if(empty($errors)==true){
        if(is_dir($desired_dir)==false){
            mkdir("$desired_dir", 0755);        // Create directory if it does not exist
        }




            $locationing="brand_images/$file_name";
            move_uploaded_file($file_tmp,$locationing);


             $image = imagecreatefromstring(file_get_contents("brand_images/$file_name"));
        $rand = rand(111,43943749739349343);
        $filename = "brand_images/$rand-33$file_name";

         if($image_width >= 840 && $image_height >= 680)
        {
        $thumb_width = 1200;
        $thumb_height = 700;
        }else{
        $thumb_width = 800;
        $thumb_height = 533;
        }

        $width = imagesx($image);
        $height = imagesy($image);

        $original_aspect = $width / $height;
        $thumb_aspect = $thumb_width / $thumb_height;

        if ( $original_aspect >= $thumb_aspect )
        {
           // If image is wider than thumbnail (in aspect ratio sense)
           $new_height = $thumb_height;
           $new_width = $width / ($height / $thumb_height);
        }
        else
        {
           // If the thumbnail is wider than the image
           $new_width = $thumb_width;
           $new_height = $height / ($width / $thumb_width);
        }

        $thumb = imagecreatetruecolor( $thumb_width, $thumb_height );

        // Resize and crop
        imagecopyresampled($thumb,
               $image,
               0 - ($new_width - $thumb_width) / 2, // Center the image horizontally
               0 - ($new_height - $thumb_height) / 2, // Center the image vertically
               0, 0,
               $new_width, $new_height,
               $width, $height);
        imagejpeg($thumb, $filename, 80);

                                                       move_uploaded_file($tmp_name, $filename);


mysql_query("INSERT INTO gallery VALUES('','brand_images/$rand-33$file_name','$fk_id')");

        echo"<script>

 window.location = document.URL.replace(/#$/, '');

        </script>";
        }

This is the html

<form action="" enctype="multipart/form-data"  method="POST">
       <h3 class="no_margin-top">Upload a new image</h3>
        <hr>
       <input type="hidden" name="fk_id" value="<?php echo $brand->brand_id ?>">
      <input name="upload_gal" type="submit" class="btn btn-sm pull-right btn-success" value="Upload">
     Upload image: <input type="file" name="files[]" multiple>
     <p class="text-danger top-buffer">If image is larger than 800x533, the image would be cropped</p>
  </form>

Answer 3

Problem

The problem is located in the following line:

imagecopyresampled($dimg, $simg, -$int_width, 0, 0, 0, $adjusted_width, $nh, $w, $h);

Why are you using a negative value as destination's x? Your source image is actually put at the left of your target image, so your target image appears empty.

Solution

I invite you to use the following function to resize your image:

function resizePreservingAspectRatio($img, $targetWidth, $targetHeight)
{
   $srcWidth = imagesx($img);
   $srcHeight = imagesy($img);

   // Determine new width / height preserving aspect ratio
   $srcRatio = $srcWidth / $srcHeight;
   $targetRatio = $targetWidth / $targetHeight;
   if (($srcWidth <= $targetWidth) && ($srcHeight <= $targetHeight))
   {
      $imgTargetWidth = $srcWidth;
      $imgTargetHeight = $srcHeight;
   }
   else if ($targetRatio > $srcRatio)
   {
      $imgTargetWidth = (int) ($targetHeight * $srcRatio);
      $imgTargetHeight = $targetHeight;
   }
   else
   {
      $imgTargetWidth = $targetWidth;
      $imgTargetHeight = (int) ($targetWidth / $srcRatio);
   }

   // Creating new image with desired size
   $targetImg = imagecreatetruecolor($targetWidth, $targetHeight);

   // Add transparency if your reduced image does not fit with the new size
   $targetTransparent = imagecolorallocate($targetImg, 255, 0, 255);
   imagefill($targetImg, 0, 0, $targetTransparent);
   imagecolortransparent($targetImg, $targetTransparent);

   // Copies image, centered to the new one (if it does not fit to it)
   imagecopyresampled(
      $targetImg, $img, ($targetWidth - $imgTargetWidth) / 2, // centered
      ($targetHeight - $imgTargetHeight) / 2, // centered
      0, 0, $imgTargetWidth, $imgTargetHeight, $srcWidth, $srcHeight
   );

   return $targetImg;
}

Implementation

<?php
$newname = md5(rand() * time());
$file1 = isset($_FILES['files']['name'][0]) ? $_FILES['files']['name'][0] : null;
$file2 = isset($_FILES['files']['name'][1]) ? $_FILES['files']['name'][1] : null;
$file3 = isset($_FILES['files']['name'][2]) ? $_FILES['files']['name'][2] : null;
$file4 = isset($_FILES['files']['name'][3]) ? $_FILES['files']['name'][3] : null;
$file5 = isset($_FILES['files']['name'][4]) ? $_FILES['files']['name'][4] : null;
if (isset($_FILES['files']))
{
   $errors = array ();
   foreach ($_FILES['files']['tmp_name'] as $key => $tmp_name)
   {
      $file_name = $key . $_FILES['files']['name'][$key];
      $file_size = $_FILES['files']['size'][$key];
      $file_tmp = $_FILES['files']['tmp_name'][$key];
      $file_type = $_FILES['files']['type'][$key];
      if ($file_size > 2097152000)
      {
         $errors[] = 'File size must be less than 2 MB';
      }
      $desired_dir = "user_data/";
      if (empty($errors) == true)
      {
         if (is_dir($desired_dir) == false)
         {
            mkdir("$desired_dir", 0700);        // Create directory if it does not exist
         }
         if (is_dir("$desired_dir/" . $file_name) == false)
         {
            move_uploaded_file($file_tmp, "$desired_dir/" . $newname . $file_name);
         }
         else
         {                                  // rename the file if another one exist
            $new_dir = "$desired_dir/" . $newname . $file_name;
            rename($file_tmp, $new_dir);
         }
      }
      else
      {
         print_r($errors);
      }
   }
   if (empty($error))
   {
      echo "FILE : $file1<br>";
      echo "FILE : $file2<br>";
      echo "FILE : $file3<br>";
      echo "FILE : $file4<br>";
      echo "FILE : $file5<br>";
   }
   $orig_directory = "$desired_dir";    //Full image folder
   $thumb_directory = "thumb/";    //Thumbnail folder

   /* Opening the thumbnail directory and looping through all the thumbs: */
   $dir_handle = @opendir($orig_directory); //Open Full image dirrectory
   if ($dir_handle > 1)
   { //Check to make sure the folder opened
      $allowed_types = array ('jpg', 'jpeg', 'gif', 'png');
      $file_type = array ();
      $ext = '';
      $title = '';
      $i = 0;

      while ($file_name = @readdir($dir_handle))
      {
         /* Skipping the system files: */
         if ($file_name == '.' || $file_name == '..')
            continue;

         $file_type = explode('.', $file_name);    //This gets the file name of the images
         $ext = strtolower(array_pop($file_type));

         /* Using the file name (withouth the extension) as a image title: */
         $title = implode('.', $file_type);
         $title = htmlspecialchars($title);

         /* If the file extension is allowed: */
         if (in_array($ext, $allowed_types))
         {

            /* If you would like to inpute images into a database, do your mysql query here */

            /* The code past here is the code at the start of the tutorial */
            /* Outputting each image: */

            $nw = 100;
            $nh = 100;
            $source = "$desired_dir{$file_name}";
            $stype = explode(".", $source);
            $stype = $stype[count($stype) - 1];
            $dest = "thumb/{$file_name}";

            $size = getimagesize($source);
            $w = $size[0];
            $h = $size[1];

            switch ($stype)
            {
               case 'gif':
                  $simg = imagecreatefromgif($source);
                  break;
               case 'jpg':
                  $simg = imagecreatefromjpeg($source);
                  break;
               case 'png':
                  $simg = imagecreatefrompng($source);
                  break;
            }

            $dimg = resizePreservingAspectRatio($simg, $nw, $nh);
            imagepng($dimg, $dest);
         }
      }

      /* Closing the directory */
      @closedir($dir_handle);
   }
}

function resizePreservingAspectRatio($img, $targetWidth, $targetHeight)
{
   $srcWidth = imagesx($img);
   $srcHeight = imagesy($img);

   // Determine new width / height preserving aspect ratio
   $srcRatio = $srcWidth / $srcHeight;
   $targetRatio = $targetWidth / $targetHeight;
   if (($srcWidth <= $targetWidth) && ($srcHeight <= $targetHeight))
   {
      $imgTargetWidth = $srcWidth;
      $imgTargetHeight = $srcHeight;
   }
   else if ($targetRatio > $srcRatio)
   {
      $imgTargetWidth = (int) ($targetHeight * $srcRatio);
      $imgTargetHeight = $targetHeight;
   }
   else
   {
      $imgTargetWidth = $targetWidth;
      $imgTargetHeight = (int) ($targetWidth / $srcRatio);
   }

   // Creating new image with desired size
   $targetImg = imagecreatetruecolor($targetWidth, $targetHeight);

   // Add transparency if your reduced image does not fit with the new size
   $targetTransparent = imagecolorallocate($targetImg, 255, 0, 255);
   imagefill($targetImg, 0, 0, $targetTransparent);
   imagecolortransparent($targetImg, $targetTransparent);

   // Copies image, centered to the new one (if it does not fit to it)
   imagecopyresampled(
      $targetImg, $img, ($targetWidth - $imgTargetWidth) / 2, // centered
      ($targetHeight - $imgTargetHeight) / 2, // centered
      0, 0, $imgTargetWidth, $imgTargetHeight, $srcWidth, $srcHeight
   );

   return $targetImg;
}

?>

<form method="post" enctype="multipart/form-data">
   <input name="files[]" type="file"/><br/>
   <input name="files[]" type="file"/><br/>
   <input name="files[]" type="file"/><br/>
   <input name="files[]" type="file"/><br/>
   <input name="files[]" type="file"/><br/>
   <input type="submit"/>
</form>

Note: I am saving as PNG, as if you want a 100x100 image using a non-square image (such as 800x600), and without breaking its aspect ratio, we should put transparency behind the unused space and JPEG do not support it.

Answer 4

The following code will solve the problem by mapping to the correct imagecreatefrom* function or throw an exception with the invalid image type.

switch(strtolower($stype)) {
            case 'gif':
                $simg = imagecreatefromgif($source);
                break;
            case 'jpg':
            case 'jpeg':
                $simg = imagecreatefromjpeg($source);
                break;
            case 'png':
                $simg = imagecreatefrompng($source);
                break;
            default:
            throw new \Exception('invalid image type :'.$stype);
            break;
        }