image-resize via ImageWorkshop (PHP) - Link: http://phpimageworkshop.com/

imageResize.php

<?php

/**
 * Get the name without extension
 *
 * @param String $filename
 *
 * @return String | false (by error)
 */
function getFileName($filename)
{
  $return = false;

  if (($filename = basename($filename)) && ($dot_pos = strrpos($filename, "."))) {
    $return = substr($filename, 0, $dot_pos);
  }

  return $return;
}

/**
 * get file-extension
 *
 * @param String $filename
 *
 * @return String | false (by error)
 */
function getFileExtension($filename)
{
  $ext = false;

  if (function_exists('pathinfo') && (file_exists($filename))) {
    $ext = pathinfo($filename, PATHINFO_EXTENSION);
  } else {

    if (stristr($filename, '.') !== false) {
      $a = explode('.', $filename);
      $ext = array_pop($a);
    }

  }

  if ($ext !== false) {
    $ext = strtolower($ext);
  }

  return $ext;
}

/**
 * resize a image and save it to a new file
 *
 * @param String $sourceImage
 * @param String $thumbNameExtra
 * @param mixed  $widthInPX
 * @param mixed  $heightInPX
 * @param Int    $compression
 *
 * @return String or false on error
 */
function imageResize($sourceImage, $thumbNameExtra = '_thumb', $widthInPX = null, $heightInPX = null, $compression = 90)
{

  if ($widthInPX == null && $heightInPX == null) {
    return false;
  }

  if (!is_file($sourceImage)) {
    return false;
  }

  $fileName = getFileName($sourceImage);
  $fileExt = getFileExtension($sourceImage);

  if (!$fileName || !$fileExt) {
    return false;
  }

  $newFileName = $fileName . $thumbNameExtra . '.' . $fileExt;

  $layer = ImageWorkshop::initFromPath($sourceImage);
  $layer->resizeInPixel($widthInPX, $heightInPX, true, 0, 0, 'MM');
  $layer->save('/var/www/.../todo/', $newFileName, false, null, $compression);

  return $newFileName;
}