One can now add a HTTP header for Cache-Control in the config file, #109.

webroot/img.php

@@ -928,6 +928,18 @@ $cachePath = getConfig('cache_path', __DIR__ . '/../cache/');
 
 
 
+/**
+ * Get the cachepath from config.
+ */
+$cacheControl = getConfig('cache_control', null);
+
+if ($cacheControl) {
+    verbose("cacheControl = $cacheControl");
+    $img->addHTTPHeader("Cache-Control", $cacheControl);
+}
+
+
+
 /**
  * Prepare a dummy image and use it as source image.
  */