document 'buffer' types

Author: fferri

meta/callbacks.xml

@@ -694,7 +694,7 @@
                 <description>topic name, e.g.: '/cmd_vel'</description>
             </param>
             <param name="topicCallback" type="string">
-                <description>name of the callback function, which will be called as: topicCallback(string data, number width, number height)</description>
+                <description>name of the callback function, which will be called as: topicCallback(buffer data, int width, int height)</description>
             </param>
             <param name="queueSize" type="int" default="1">
                 <description>(optional) queue size</description>
@@ -776,7 +776,7 @@
             <param name="publisherHandle" type="string">
                 <description>the publisher handle</description>
             </param>
-            <param name="data" type="string">
+            <param name="data" type="buffer">
                 <description>the image data</description>
             </param>
             <param name="width" type="int">
@@ -1062,7 +1062,7 @@
     <script-function name="imageTransportCallback">
         <description>Callback for ROS ImageTransport subscription.</description>
         <params>
-            <param name="data" type="string">
+            <param name="data" type="buffer">
                 <description>the image data</description>
             </param>
             <param name="width" type="int">