The d-touch analyser is a cross-platform desktop application developed to help in the design of valid d-touch markers.

August 2011 The analyser is unfortunately currently unavailable. Our efforts at the moment are focussed on the audio d-touch project. We will try to bring the d-touch analyser back online in the next few months. If you require further information please contact Enrico Costanza

Important notes:

  1. By downloading the application you agree to the terms of the license. We log usage data from the d-touch analyser to inform our research about designable visual markers;
  2. The application is in early stage of development, please don't be surprised if it crashes or gives you strange results.




Quick guide

Candidate markers produced with any graphic application can be imported in the d-touch analyser either as graphic files (e.g. .jpg, .png, ..) or through copy & paste (only available on some platforms).

Once a drawing has been imported in DTAnalyser, the application analyses it (please be patient this can take up to some minutes) and displays the results. The first thing to look at is the message under the toolbar, this shows either "Valid marker" and the marker ID or "Not a valid marker". Please ignore the trailing letter in the marker ID (it will normally be 'b' or sometimes 'w'). Under this message one or more other lines of text provides more information from the analysis. Below this text are 3 to 7 small images: you can select each of them by clicking on it and it gets displayed at full size at the bottom of the application. You can enlarge or zoom out by using the following two buttons in the toolbar:



If the drawing is not a valid marker, the DTAnalyser tries to guess which specific aspect of the rules is violated, and this information is displayed in the second line of text (above the row of icons). Examples include regions being nested too deeply, too many white regions being empty or having less than 3 white regions. Please note that this is a guess. If the drawing does not follow at all the d-touch rules, the application will suggest to check the instructions: please do! Sometimes problems can be caused by strokes being too thin or by gaps inside areas which are supposed to be filled . The different views offered by the DTAnalyser can help spotting and fixing these problems.

The first view, named “Original” is simply the image imported in the application. Next to it is the “B / W” view which shows how the image is converted to pure black and white. In this conversion sometimes there may be unexpected results, in particular, thin lines or small regions can be read as white rather than black. It is possible to examine the B / W view to try and spot this kind of problems, however the next view “Regions” should make it a lot easier. The “Regions” view shows how the computer divides the drawing into separate regions by colouring them with different colours: white regions are coloured in light colours and black regions in dark ones. Different regions have different colours, so for example if two white regions are separated by a black line they should show in two different colours. However, if the black line is not complete, the supposedly-two regions will in reality be only one region, all filled in the same colour. For example consider the following drawing and its “Regions” decomposition:



You can notice that both the background and the left ear are white. This means that the two are in fact the same region. A closer inspection (in the application you can zoom in) reveals that the black line enclosing the left ear, towards the bottom near the head, is actually broken. (please note that the same may happen with different colours, not just white)

If the drawing is a valid marker, the application will determine how easily it can be read by a low resolution camera (e.g. from a mobile phone). This information is displayed in the text line under the marker ID, and in the 4 views on the right: “Weak”, “Distorted”, “Broken B/W” and “Broken Regs.”. The “Weak” view highlights in red the parts of the marker that are least robust, typically this are small details. If the marker contains a lot of red highlights, it is actually a good sign, as it means that it is uniform. The “Distorted” view shows the amount of distortion (due for example to blur or low resolution scanning) that causes the problems highlighted in the “Weak” view. The “Broken B/W” and “Broken Regs.” views have the same function as the “B/W” and “Regions” views described above, except that they are relative to the distorted marker. In fact, these last four views can be used to understand how the distortion modifies the structure of the marker, and therefore how to modify the marker to make it more robust, if necessary. Please note that any marker, for how robust it is, will always break at some low resolution. The goal is normally (but not necessarily always) to produce markers that are good to read from mobile phones.

Once you are happy with your design, please share it by pressing the following button in the tool bar, this will upload it to our web gallery:



Please note that this function is available only for valid markers. The application will then check if the ID of the current marker clashes with any existing marker. If there is no conflict a dialogue window will appear asking you to add a brief text description for the marker. In case of an ID clash, please try to modify the marker and solve the conflict.