Hi, well, I asked exactly about natural feature tracking of predefined images (3). However, as far as I understand, this will not be delivered as part of the Augmented Reality GE? Is the respective version of ALVAR Tracker publicitly available that is capable of this feature? What about an integration through Google Chrome's Native Client, for instance? I'm really sad about such a limited feature set of the Augmented Reality GE. From the perspective of Xflow, I cannot see any added value over the Marker Tracking SE, which is based on jsARToolkit and already available since September 2013. Kind regards, Stefan Sent from Samsung Mobile <div>-------- Original message --------</div><div>From: Antti Karhu <antti.karhu at cie.fi> </div><div>Date:2014/02/21 10:08 (GMT+01:00) </div><div>To: Stefan Lemme <stefan.lemme at dfki.de> </div><div>Cc: Arto Heikkinen <arto.heikkinen at cie.fi>,Ari Okkonen <ari.okkonen at cie.fi>,"FI-WARE, MiWi" <fiware-miwi at lists.fi-ware.eu> </div><div>Subject: Re: Hands-on: Augmented Reality GE </div><div> </div>Hi, Good questions, hope this answer will clear things There is the crucial need for markerless tracking using predefined image markers in FIcontent. It is one of the features of the utilized ALVAR library. When will it be exposed through JavaScript and hopefully also Xflow? Let’s start with some definitions: (1) Marker: A fiducial marker is defined as a square box that is divided into a grid. The outside cells of the grid are always black and the inside cells can be either white or black. (2) Image Marker: An image marker is very similar to the Marker with the difference being that the resolution of the grid is a bit larger and the inside cells can form a shape or logo. (3) Natural Feature Image: A natural feature image is simply an image, it might be computer generated or taken by a camera. The image doesn’t have any borders nor doesn't necessarily have to be square or rectangular. There are multiple versions of ALVAR with different level of features supported. The one that have been ported to javascript is called ALVAR MOBILE. It supports detecting and tracking markers(1) and image markers(2). The image markers must have a clearly recognizable border and the contents must not have too much detail but rather be made up of solid shapes or big block letters. The ideal resolution for image markers is spanning from 8x8 to 32x32. There is already a version that exposes the detecting and tracking image markers through Xflow: https://github.com/Cyberlightning/Cyber-WeX/blob/master/DataflowProcessing/demos/xflowAR/index.php . I haven’t included this to the AR GE yet, because there is serious problems with accuracy and performance with mobile devices. There is also an another version called ALVAR Tracker, that implements a generic 6DOF tracker but can also be adapted to detect and track (3) natural feature images. This version is not ported to javascript nor won’t be ported in near future. The ALVAR Mobile was ported to javascript using emscripten and this was quite an easy process because the ALVAR Mobile doesn’t have any third party dependencies. However this isn’t the case with the ALVAR Tracker. The guys on VTT thought that trying to port it to javascript is much bigger task, and because it has a multi-threaded AR pipeline with hardware acceleration(SIMD, NEON) that can’t be currently achieved with javascript, it is basically just waste of time. To what degree do you take advantage of hardware acceleration, in particular to be used on mobile devices? There is no hardware acceleration used now, and no plans to use it for next release 3.3. The situation is that the emscripten ported ALVAR is machine generated javascript, so it’s pretty much a black box, you put the video frame in and get the transform matrix out. Trying to identify which part of the code could benefit from hardware acceleration is hard. Even harder would be to replace parts of the javascript code with an equivalent GLSL or WebCL parts. Obviously someone have to write the shaders of those parts first. Because of the limited resources, unfortunately there is no change that this will happen at any time soon. -Antti- 2014-02-20 20:58 GMT+02:00 Stefan Lemme <stefan.lemme at dfki.de>: Hello, after our workshop last week a few questions about the Augmented Reality GE raised and hopefully you can provide some insights. There is the crucial need for markerless tracking using predefined image markers in FIcontent. It is one of the features of the utilized ALVAR library. When will it be exposed through JavaScript and hopefully also Xflow? To what degree do you take advantage of hardware acceleration, in particular to be used on mobile devices? I would really appreciate to get some more informations about the open questions. Best regards, Stefan -- ******************************************************** Stefan Lemme DFKI GmbH Agenten und Simulierte Realität Campus, Geb. 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