Nimrod's Tech Blog » PHP image resize

Some time ago needed to resize images in my server, started reading on how this could be done and ended up forking an existing project on github and improving it.

The result : https://github.com/Nimrod007/PHP_image_resize

What does it do ?

resizes images
saves them with a new name
keeps transparent png
accepts images as string or as a file
handles all common image types in the same function

The solution :

<?php
/**
 * easy image resize function
 * @param  $file - file name to resize
 * @param  $string - The image data, as a string
 * @param  $width - new image width
 * @param  $height - new image height
 * @param  $proportional - keep image proportional, default is no
 * @param  $output - name of the new file (include path if needed)
 * @param  $delete_original - if true the original image will be deleted
 * @param  $use_linux_commands - if set to true will use "rm" to delete the image, if false will use PHP unlink
 * @param  $quality - enter 1-100 (100 is best quality) default is 100
 * @return boolean|resource
 */
  function smart_resize_image($file,
                              $string             = null,
                              $width              = 0, 
                              $height             = 0, 
                              $proportional       = false, 
                              $output             = 'file', 
                              $delete_original    = true, 
                              $use_linux_commands = false,
  							  $quality = 100
  		 ) {
      
    if ( $height <= 0 && $width <= 0 ) return false;
    if ( $file === null && $string === null ) return false;

    # Setting defaults and meta
    $info                         = $file !== null ? getimagesize($file) : getimagesizefromstring($string);
    $image                        = '';
    $final_width                  = 0;
    $final_height                 = 0;
    list($width_old, $height_old) = $info;
	$cropHeight = $cropWidth = 0;

    # Calculating proportionality
    if ($proportional) {
      if      ($width  == 0)  $factor = $height/$height_old;
      elseif  ($height == 0)  $factor = $width/$width_old;
      else                    $factor = min( $width / $width_old, $height / $height_old );

      $final_width  = round( $width_old * $factor );
      $final_height = round( $height_old * $factor );
    }
    else {
      $final_width = ( $width <= 0 ) ? $width_old : $width;
      $final_height = ( $height <= 0 ) ? $height_old : $height;
	  $widthX = $width_old / $width;
	  $heightX = $height_old / $height;
	  
	  $x = min($widthX, $heightX);
	  $cropWidth = ($width_old - $width * $x) / 2;
	  $cropHeight = ($height_old - $height * $x) / 2;
    }

    # Loading image to memory according to type
    switch ( $info[2] ) {
      case IMAGETYPE_JPEG:  $file !== null ? $image = imagecreatefromjpeg($file) : $image = imagecreatefromstring($string);  break;
      case IMAGETYPE_GIF:   $file !== null ? $image = imagecreatefromgif($file)  : $image = imagecreatefromstring($string);  break;
      case IMAGETYPE_PNG:   $file !== null ? $image = imagecreatefrompng($file)  : $image = imagecreatefromstring($string);  break;
      default: return false;
    }
    
    
    # This is the resizing/resampling/transparency-preserving magic
    $image_resized = imagecreatetruecolor( $final_width, $final_height );
    if ( ($info[2] == IMAGETYPE_GIF) || ($info[2] == IMAGETYPE_PNG) ) {
      $transparency = imagecolortransparent($image);
      $palletsize = imagecolorstotal($image);

      if ($transparency >= 0 && $transparency < $palletsize) {
        $transparent_color  = imagecolorsforindex($image, $transparency);
        $transparency       = imagecolorallocate($image_resized, $transparent_color['red'], $transparent_color['green'], $transparent_color['blue']);
        imagefill($image_resized, 0, 0, $transparency);
        imagecolortransparent($image_resized, $transparency);
      }
      elseif ($info[2] == IMAGETYPE_PNG) {
        imagealphablending($image_resized, false);
        $color = imagecolorallocatealpha($image_resized, 0, 0, 0, 127);
        imagefill($image_resized, 0, 0, $color);
        imagesavealpha($image_resized, true);
      }
    }
    imagecopyresampled($image_resized, $image, 0, 0, $cropWidth, $cropHeight, $final_width, $final_height, $width_old - 2 * $cropWidth, $height_old - 2 * $cropHeight);
	
	
    # Taking care of original, if needed
    if ( $delete_original ) {
      if ( $use_linux_commands ) exec('rm '.$file);
      else @unlink($file);
    }

    # Preparing a method of providing result
    switch ( strtolower($output) ) {
      case 'browser':
        $mime = image_type_to_mime_type($info[2]);
        header("Content-type: $mime");
        $output = NULL;
      break;
      case 'file':
        $output = $file;
      break;
      case 'return':
        return $image_resized;
      break;
      default:
      break;
    }
    
    # Writing image according to type to the output destination and image quality
    switch ( $info[2] ) {
      case IMAGETYPE_GIF:   imagegif($image_resized, $output);    break;
      case IMAGETYPE_JPEG:  imagejpeg($image_resized, $output, $quality);   break;
      case IMAGETYPE_PNG:
        $quality = 9 - (int)((0.9*$quality)/10.0);
        imagepng($image_resized, $output, $quality);
        break;
      default: return false;
    }

    return true;
  }

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<?php

/**

* easy image resize function

* @param $file - file name to resize

* @param $string - The image data, as a string

* @param $width - new image width

* @param $height - new image height

* @param $proportional - keep image proportional, default is no

* @param $output - name of the new file (include path if needed)

* @param $delete_original - if true the original image will be deleted

* @param $use_linux_commands - if set to true will use "rm" to delete the image, if false will use PHP unlink

* @param $quality - enter 1-100 (100 is best quality) default is 100

* @return boolean|resource

function smart_resize_image($file,

$string = null,

$width = 0,

$height = 0,

$proportional = false,

$output = 'file',

$delete_original = true,

$use_linux_commands = false,

$quality = 100

) {

if ( $height <= 0 && $width <= 0 ) return false;

if ( $file === null && $string === null ) return false;

# Setting defaults and meta

$info = $file !== null ? getimagesize($file) : getimagesizefromstring($string);

$image = '';

$final_width = 0;

$final_height = 0;

list($width_old, $height_old) = $info;

$cropHeight = $cropWidth = 0;

# Calculating proportionality

if ($proportional) {

if ($width == 0) $factor = $height/$height_old;

elseif ($height == 0) $factor = $width/$width_old;

else $factor = min( $width / $width_old, $height / $height_old );

$final_width = round( $width_old * $factor );

$final_height = round( $height_old * $factor );

}

else {

$final_width = ( $width <= 0 ) ? $width_old : $width;

$final_height = ( $height <= 0 ) ? $height_old : $height;

$widthX = $width_old / $width;

$heightX = $height_old / $height;

$x = min($widthX, $heightX);

$cropWidth = ($width_old - $width * $x) / 2;

$cropHeight = ($height_old - $height * $x) / 2;

}

# Loading image to memory according to type

switch ( $info[2] ) {

case IMAGETYPE_JPEG: $file !== null ? $image = imagecreatefromjpeg($file) : $image = imagecreatefromstring($string); break;

case IMAGETYPE_GIF: $file !== null ? $image = imagecreatefromgif($file) : $image = imagecreatefromstring($string); break;

case IMAGETYPE_PNG: $file !== null ? $image = imagecreatefrompng($file) : $image = imagecreatefromstring($string); break;

default: return false;

}

# This is the resizing/resampling/transparency-preserving magic

$image_resized = imagecreatetruecolor( $final_width, $final_height );

if ( ($info[2] == IMAGETYPE_GIF) || ($info[2] == IMAGETYPE_PNG) ) {

$transparency = imagecolortransparent($image);

$palletsize = imagecolorstotal($image);

if ($transparency >= 0 && $transparency < $palletsize) {

$transparent_color = imagecolorsforindex($image, $transparency);

$transparency = imagecolorallocate($image_resized, $transparent_color['red'], $transparent_color['green'], $transparent_color['blue']);

imagefill($image_resized, 0, 0, $transparency);

imagecolortransparent($image_resized, $transparency);

}

elseif ($info[2] == IMAGETYPE_PNG) {

imagealphablending($image_resized, false);

$color = imagecolorallocatealpha($image_resized, 0, 0, 0, 127);

imagefill($image_resized, 0, 0, $color);

imagesavealpha($image_resized, true);

}

imagecopyresampled($image_resized, $image, 0, 0, $cropWidth, $cropHeight, $final_width, $final_height, $width_old - 2 * $cropWidth, $height_old - 2 * $cropHeight);

# Taking care of original, if needed

if ( $delete_original ) {

if ( $use_linux_commands ) exec('rm '.$file);

else @unlink($file);

}

# Preparing a method of providing result

switch ( strtolower($output) ) {

case 'browser':

$mime = image_type_to_mime_type($info[2]);

header("Content-type: $mime");

$output = NULL;

break;

case 'file':

$output = $file;

break;

case 'return':

return $image_resized;

break;

default:

break;

}

# Writing image according to type to the output destination and image quality

switch ( $info[2] ) {

case IMAGETYPE_GIF: imagegif($image_resized, $output); break;

case IMAGETYPE_JPEG: imagejpeg($image_resized, $output, $quality); break;

case IMAGETYPE_PNG:

$quality = 9 - (int)((0.9*$quality)/10.0);

imagepng($image_resized, $output, $quality);

break;

default: return false;

}

return true;

}

check it out : https://github.com/Nimrod007/PHP_image_resize

http://www.uglyapp.com UglyApp

Hi,

I am testing the above code.

I get an error with a large jpeg file. (3.5 meg).

created the scaled image

Fatal error: Out of memory (allocated 33030144) (tried to allocate 12000 bytes) in /homepages/8/d278278548/htdocs/forGoodnessCakes/techy/createthumb2.php on line 40

Line 40 = case IMAGETYPE_JPEG: $image = imagecreatefromjpeg($file); break;

test image http://www.forgoodnesscakes.info/techy/images/LSST_Rendering_VK.jpg

It also fails when I use png files.

eg http://www.forgoodnesscakes.info/techy/images/Screen%20Shot%202014-09-09%20at%2019.55.08.png

Cheers

Mr Warby
- Nimrod007
  
  Hi
  check your php details (php.ini) for memory limits… a 3.5 mb pic should be a problem
Philip Sorokin

Amazing! Easy to use and very quality result! A million thanks to the developer!
http://www.webineh.net/ وحید الوندی

tank you

http://www.webineh.net
http://www.webineh.net/ وحید الوندی

very very goooood
Jonathan Nguyen

Thank you so much. I have found this class many many times
Gergely H

Great plugin, works flawlessly. I recommend wrapping it in a class, will be easier to integrate it into OOP apps. Thanks!
http://harshamadushan.webuda.com Harsha Madushan

Perfect and Clean!
V!ral

Thanks, Resizing working great.

However it’s converting transparent .png images background into black color background.

Can you help me for this ?
Pingback: Compress image on upload php - DexPage()
Justin

i want to resize images submitted from POST form, May I know how to use this function from post data
- Nimrod007
  
  http://www.w3schools.com/php/php_file_upload.asp shows an example of uploading file to you server, after you have the file path you can pass it to the resize function
  - Justin
    
    Thank You @nimrod007:disqus for your reply. I know how to let my user to upload photo to my server. but i dont know how to pass the image posted to the resize function then store it. following is my existing php script:
    
    if((($_FILES[‘image1’][‘type’])==’image/gif’)
    or (($_FILES[‘image1’][‘type’])==’image/jpeg’)
    or (($_FILES[‘image1’][‘type’])==’image/pjpeg’)
    or (($_FILES[‘image1’][‘type’])==’image/bmp’)
    && ($_FILES[‘image1’][‘size’]) 0){
    echo “Return Code:” . $_FILES[‘image1’][‘error’];
    }
    else {
    $extension1 = pathinfo($_FILES[‘image1’][‘name’], PATHINFO_EXTENSION );
    $image1 = ‘(‘. $date.$msec. ‘)image1’. ‘.’ . $extension1;
    move_uploaded_file($_FILES[‘image1’][‘tmp_name’],’../upload/’.$image1);
    }
    }
    
    My $image1 will be “filename”.jpg and it will be save into my “upload” folder.
kou soreach

Hi should I pass some values to function smart_resize_image()
please help
chakotha

Brilliant share Nimrod. Many thanks.
- foodrecipesfinder
  
  how could you so that? please help
Mssrachita Mahajan

Excellent work man … you save my day .thanks
- foodrecipesfinder
  
  how to applt this? please help
Aakash Martand

I’m facing a problem. After conversion, image rotates by 90 degree or 180 degree. Please help.
- Guilherme Corrêa Peralta
  
  having the same issue here, did you find a solution?
  - Julian Mallett
    
    I haven’t tested, but this is probably because the image orientation is stored in the file metadata which this function removes. The iPhone does image rotation like this (and others, I’m sure).
    
    I haven’t fixed the problem in GD, but if you use imagemagick you can fix the rotation before the metadata is stripped.
    
    function autoRotateImage(Imagick $image)
    {
    switch ($image->getImageOrientation()) {
    case Imagick::ORIENTATION_TOPLEFT:
    break;
    case Imagick::ORIENTATION_TOPRIGHT:
    $image->flopImage();
    break;
    case Imagick::ORIENTATION_BOTTOMRIGHT:
    $image->rotateImage(“#000”, 180);
    break;
    case Imagick::ORIENTATION_BOTTOMLEFT:
    $image->flopImage();
    $image->rotateImage(“#000”, 180);
    break;
    case Imagick::ORIENTATION_LEFTTOP:
    $image->flopImage();
    $image->rotateImage(“#000”, -90);
    break;
    case Imagick::ORIENTATION_RIGHTTOP:
    $image->rotateImage(“#000”, 90);
    break;
    case Imagick::ORIENTATION_RIGHTBOTTOM:
    $image->flopImage();
    $image->rotateImage(“#000”, 90);
    break;
    case Imagick::ORIENTATION_LEFTBOTTOM:
    $image->rotateImage(“#000”, -90);
    break;
    default: // Invalid orientation
    break;
    }
    
    $image->setImageOrientation(Imagick::ORIENTATION_TOPLEFT);
    }
Cetto Lakstio

how to apply the above code in phpBB?
https://cyberdude.trenkey.com Cyber Dude

Thank you very much Dude 😀
Denis

Obrigado, funciona perfeitamente, belo trabalho !
Beaty4life with Mia Mia

For some reason, this function is no longer saving the new image file and I haven’t been able to figure out why. I’m using a Windows 10 machine with XAMPP and it has worked without too much trouble in the past, but for the last couple of days, it hasn’t worked. Is there an easy way to troubleshoot this to figure out what the problem might be?
- Murray Collingwood
  
  The easy solution is to stop using Windows 10, or anything Windows. (From an ex-Windows user)
https://gr.linkedin.com/in/stratosnikolaidis Stratos Nikolaidis

Hey Nimrod, thanks for this, really helpful! Just one suggestion for an extra option perhaps, on doing nothing in case of zooming? Just an idea… Thanks again!
Ehsan Khan

thanks . put this code to top of the function to work more better…
if (!is_dir(dirname($output))){
mkdir(dirname($output), 0777, true);
}
Ethan

The fix is here: https://stackoverflow.com/questions/7489742/php-read-exif-data-and-adjust-orientation/9207128?utm_medium=organic&utm_source=google_rich_qa&utm_campaign=google_rich_qa

Just put the answer right under imagecopyresampled (line 85) and pass in the orientation information like so:

$exif = exif_read_data($target_file);
$ort = $exif[‘IFD0’][‘Orientation’];
smart_resize_image($target_file, null, 400, 400, true, $target_file_thumb, false, false, 80, $ort);