diff --git a/CImage.php b/CImage.php
index a1fd817..dc64329 100644
--- a/CImage.php
+++ b/CImage.php
@@ -155,6 +155,13 @@ class CImage
 
 
 
+    /**
+     * Do lossy output using external postprocessing tools.
+     */
+    private $lossy = null;
+
+
+
     /**
      * Verbose mode to print out a trace and display the created image
      */
@@ -190,7 +197,15 @@ class CImage
 
 
     /**
-     * Path to command for filter optimize, for example optipng or null.
+     * Path to command for lossy optimize, for example pngquant.
+     */
+    private $pngLossy;
+    private $pngLossyCmd;
+
+
+
+    /**
+     * Path to command for filter optimize, for example optipng.
      */
     private $pngFilter;
     private $pngFilterCmd;
@@ -198,7 +213,7 @@ class CImage
 
 
     /**
-     * Path to command for deflate optimize, for example pngout or null.
+     * Path to command for deflate optimize, for example pngout.
      */
     private $pngDeflate;
     private $pngDeflateCmd;
@@ -827,6 +842,9 @@ class CImage
             // Output format
             'outputFormat' => null,
             'dpr'          => 1,
+
+            // Postprocessing using external tools
+            'lossy' => null,
         );
 
         // Convert crop settings from string to array
@@ -2345,6 +2363,14 @@ class CImage
             $this->jpegOptimizeCmd = null;
         }
 
+        if (array_key_exists("png_lossy", $options) 
+            && $options['png_lossy'] !== false) {
+            $this->pngLossy = $options['png_lossy'];
+            $this->pngLossyCmd = $options['png_lossy_cmd'];
+        } else {
+            $this->pngLossyCmd = null;
+        }
+
         if (isset($options['png_filter']) && $options['png_filter']) {
             $this->pngFilterCmd = $options['png_filter_cmd'];
         } else {
@@ -2446,6 +2472,24 @@ class CImage
                 imagesavealpha($this->image, true);
                 imagepng($this->image, $this->cacheFileName, $this->compress);
 
+                // Use external program to process lossy PNG, if defined
+                $lossyEnabled = $this->pngLossy === true;
+                $lossySoftEnabled = $this->pngLossy === null;
+                $lossyActiveEnabled = $this->lossy === true;
+                if ($lossyEnabled || ($lossySoftEnabled && $lossyActiveEnabled)) {
+                    if ($this->verbose) {
+                        clearstatcache();
+                        $this->log("Lossy enabled: $lossyEnabled");
+                        $this->log("Lossy soft enabled: $lossySoftEnabled");
+                        $this->Log("Filesize before lossy optimize: " . filesize($this->cacheFileName) . " bytes.");
+                    }
+                    $res = array();
+                    $cmd = $this->pngLossyCmd . " $this->cacheFileName $this->cacheFileName";
+                    exec($cmd, $res);
+                    $this->Log($cmd);
+                    $this->Log($res);
+                }
+
                 // Use external program to filter PNG, if defined
                 if ($this->pngFilterCmd) {
                     if ($this->verbose) {
diff --git a/README.md b/README.md
index f256a4a..c01b5cc 100644
--- a/README.md
+++ b/README.md
@@ -49,14 +49,14 @@ There are several ways of installing. You either install the whole project which
 
 The [sourcode is available on GitHub](https://github.com/mosbth/cimage). Clone, fork or [download as zip](https://github.com/mosbth/cimage/archive/master.zip). 
 
-**Latest stable version is v0.7.15 released 2016-08-09.**
+**Latest stable version is v0.7.16 released 2016-08-09.**
 
 I prefer cloning like this. Do switch to the latest stable version.
 
 ```bash
 git clone git://github.com/mosbth/cimage.git
 cd cimage
-git checkout v0.7.15
+git checkout v0.7.16
 ```
 
 Make the cache-directory writable by the webserver.
@@ -79,7 +79,7 @@ There are some all-included bundles of `img.php` that can be downloaded and used
 Dowload the version of your choice like this.
 
 ```bash
-wget https://raw.githubusercontent.com/mosbth/cimage/v0.7.15/webroot/imgp.php
+wget https://raw.githubusercontent.com/mosbth/cimage/v0.7.16/webroot/imgp.php
 ```
 
 Open up the file in your editor and edit the array `$config`. Ensure that the paths to the image directory and the cache directory matches your environment, or create an own config-file for the script.
diff --git a/REVISION.md b/REVISION.md
index 667360e..ee6c4f0 100644
--- a/REVISION.md
+++ b/REVISION.md
@@ -5,6 +5,14 @@ Revision history
 [![Build Status](https://scrutinizer-ci.com/g/mosbth/cimage/badges/build.png?b=master)](https://scrutinizer-ci.com/g/mosbth/cimage/build-status/master)
 
 
+v0.7.16 (2016-08-09)
+-------------------------------------
+
+* Fix default mode to be production.
+* Added pngquant as extra postprocessing utility for PNG-images, #154.
+* Bug `&status` wrong variable name for fast track cache.
+
+
 v0.7.15 (2016-08-09)
 -------------------------------------
 
diff --git a/defines.php b/defines.php
index 4789fd1..3cc5c5e 100644
--- a/defines.php
+++ b/defines.php
@@ -1,6 +1,6 @@
 <?php
 // Version of cimage and img.php
-define("CIMAGE_VERSION", "v0.7.15 (2016-08-09)");
+define("CIMAGE_VERSION", "v0.7.16 (2016-08-09)");
 
 // For CRemoteImage
 define("CIMAGE_USER_AGENT", "CImage/" . CIMAGE_VERSION);
diff --git a/functions.php b/functions.php
index b46ade8..ab047e0 100644
--- a/functions.php
+++ b/functions.php
@@ -163,3 +163,24 @@ function verbose($msg = null)
 
     $log[] = $msg;
 }
+
+
+
+/**
+ * Log when verbose mode, when used without argument it returns the result.
+ *
+ * @param string $msg to log.
+ *
+ * @return void or array.
+ */
+function checkExternalCommand($what, $enabled, $commandString)
+{
+    $no = $enabled ? null : 'NOT';
+    $text = "Post processing $what is $no enabled.<br>";
+
+    list($command) = explode(" ", $commandString);
+    $no = is_executable($command) ? null : 'NOT';
+    $text .= "The command for $what is $no an executable.<br>";
+
+    return $text;
+}
diff --git a/webroot/check_system.php b/webroot/check_system.php
index b101998..1443de8 100644
--- a/webroot/check_system.php
+++ b/webroot/check_system.php
@@ -21,6 +21,9 @@ if (!$no) {
 
 echo "<strong>Checking path for postprocessing tools</strong>";
 
+echo "<br>pngquant: ";
+system("which pngquant");
+
 echo "<br>optipng: ";
 system("which optipng");
 
diff --git a/webroot/img.php b/webroot/img.php
index 15d4a96..f93227e 100644
--- a/webroot/img.php
+++ b/webroot/img.php
@@ -840,6 +840,9 @@ verbose("upscale = $upscale");
  * Get details for post processing
  */
 $postProcessing = getConfig('postprocessing', array(
+    'png_lossy'        => false,
+    'png_lossy_cmd'    => '/usr/local/bin/pngquant --force --output',
+
     'png_filter'        => false,
     'png_filter_cmd'    => '/usr/local/bin/optipng -q',
 
@@ -852,6 +855,15 @@ $postProcessing = getConfig('postprocessing', array(
 
 
 
+/**
+ * lossy - Do lossy postprocessing, if available.
+ */
+$lossy = getDefined(array('lossy'), true, null);
+
+verbose("lossy = $lossy");
+
+
+
 /**
  * alias - Save resulting image to another alias name.
  * Password always apply, must be defined.
@@ -970,7 +982,7 @@ if ($status) {
     $res = $cache->getStatusOfSubdir("srgb");
     $text .= "Cache srgb $res\n";
 
-    $res = $cache->getStatusOfSubdir($fasttrackCache);
+    $res = $cache->getStatusOfSubdir($fastTrackCache);
     $text .= "Cache fasttrack $res\n";
 
     $text .= "Alias path writable = " . is_writable($aliasPath) . "\n";
@@ -987,6 +999,11 @@ if ($status) {
     $no = extension_loaded('gd') ? null : 'NOT';
     $text .= "Extension gd is $no loaded.<br>";
 
+    $text .= checkExternalCommand("PNG LOSSY", $postProcessing["png_lossy"], $postProcessing["png_lossy_cmd"]);
+    $text .= checkExternalCommand("PNG FILTER", $postProcessing["png_filter"], $postProcessing["png_filter_cmd"]);
+    $text .= checkExternalCommand("PNG DEFLATE", $postProcessing["png_deflate"], $postProcessing["png_deflate_cmd"]);
+    $text .= checkExternalCommand("JPEG OPTIMIZE", $postProcessing["jpeg_optimize"], $postProcessing["jpeg_optimize_cmd"]);
+
     if (!$no) {
         $text .= print_r(gd_info(), 1);
     }
@@ -1055,6 +1072,7 @@ if (is_callable($hookBeforeCImage)) {
 
             // Other
             'postProcessing' => $postProcessing,
+            'lossy' => $lossy,
     ));
     verbose(print_r($allConfig, 1));
     extract($allConfig);
@@ -1139,6 +1157,9 @@ $img->log("Incoming arguments: " . print_r(verbose(), 1))
             // Output format
             'outputFormat' => $outputFormat,
             'dpr'          => $dpr,
+
+            // Postprocessing using external tools
+            'lossy' => $lossy,
         )
     )
     ->loadImageDetails()
diff --git a/webroot/img/duke.png b/webroot/img/duke.png
new file mode 100644
index 0000000..5927b8f
Binary files /dev/null and b/webroot/img/duke.png differ
diff --git a/webroot/img_config.php b/webroot/img_config.php
index 9654dd5..6da433a 100644
--- a/webroot/img_config.php
+++ b/webroot/img_config.php
@@ -41,7 +41,7 @@ return array(
      *  mode: 'production'
      */
      //'mode' => 'production',
-     'mode' => 'development',
+     //'mode' => 'development',
      //'mode' => 'strict',
 
 
@@ -321,8 +321,16 @@ return array(
      * Post processing of images using external tools, set to true or false
      * and set command to be executed.
      *
+     * The png_lossy can alos have a value of null which means that its
+     * enabled but not used as default. Each image having the option
+     * &lossy will be processed. This means one can individually choose
+     * when to use the lossy processing.
+     *
      * Default values.
      *
+     *  png_lossy:        false
+     *  png_lossy_cmd:    '/usr/local/bin/pngquant --force --output'
+     *
      *  png_filter:        false
      *  png_filter_cmd:    '/usr/local/bin/optipng -q'
      *
@@ -334,6 +342,9 @@ return array(
      */
     /*
     'postprocessing' => array(
+        'png_lossy'       => false,
+        'png_lossy_cmd'   => '/usr/local/bin/pngquant --force --output',
+
         'png_filter'        => false,
         'png_filter_cmd'    => '/usr/local/bin/optipng -q',