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Android QR-Code Detection. Cerman Martin, 0625040 mcerman@prip.tuwien.ac.at. Content. Topic & Challenges (original proposal ) IDE‘s , Languages & Libraries Chosen Approach Outlier Filtering Tuneable Parameters TODO (original proposal / what was achieved )
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Android QR-Code Detection Cerman Martin, 0625040 mcerman@prip.tuwien.ac.at
Content • Topic & Challenges (original proposal) • IDE‘s, Languages & Libraries • Chosen Approach • OutlierFiltering • Tuneable Parameters • TODO (original proposal / what was achieved) • Topic & Challenges (what was achieved) • Live Demonstration Android QR-Code Detection, Cerman Martin, 0625040
Topic & Challenges (original proposal) Topic • Detectandread QR-Codes on an Android Phone • As definedbythe ISO/IEC Standart • „Set ofblacksquares on a whitebackground“ • Varioussizes (Version 1-40) Challenges / Goals • Detectionundervariouslightingconditions • Perspectivedistortion • Detectionof QR-Code size • Real-Time Android QR-Code Detection, Cerman Martin, 0625040
IDE‘s, Languages & Libraries • MATLAB • Eclipse • ADT (Android Development Toolkit) • CDT (C++ Development Toolkit) • NDK (Android Native Development Kit) • Visual Studio 2012 • OpenCV Library Android QR-Code Detection, Cerman Martin, 0625040
Chosen Approach • „Fast Radial SymmetryforDetecting Points of Interest“, [1] • Algorithm • Transform tograyscaleandreduceimagesize • Determinegradient in x and y direction • Computeorientationandmagnitudeimage • Computesymmetryimageatcertainradii • Smooth using a Gausskernel • Non-maximumsuppression Android QR-Code Detection, Cerman Martin, 0625040
Chosen Approach (transformtograyscale) Android QR-Code Detection, Cerman Martin, 0625040
Chosen Approach (x derivative) Android QR-Code Detection, Cerman Martin, 0625040
Chosen Approach (y derivative) Android QR-Code Detection, Cerman Martin, 0625040
Chosen Approach (orientationimage) Android QR-Code Detection, Cerman Martin, 0625040
Chosen Approach (magnitudeimage) Android QR-Code Detection, Cerman Martin, 0625040
Chosen Approach (symmetryimage) Android QR-Code Detection, Cerman Martin, 0625040
Chosen Approach (thresholdedsymmetryimage) Android QR-Code Detection, Cerman Martin, 0625040
OutlierFiltering • Maximal numberofoutliersisaround 20 • Algorithm • Build a completegraph • Computeforeachvertexdistancesto all othervertices • Compute angle foreachvertextrio • Filter outliersbysettingrestrictions on maximal angle deviationanddistancedifferenceforeachvertextrio • Turned out toworkvery well Android QR-Code Detection, Cerman Martin, 0625040
Tuneable Parameters • Feature Detection • Image reductionfactor • Searchradius • Minimal numberofpositivelyaffectingpixels • Symmetrystrength • OutlierFiltering • Maximal edgelengthdifferenceofeachvertextrio • Maximal angle deviationofeachvertextrio • Frame Management • Split upsearching (different scales) andfilteringamongframes Android QR-Code Detection, Cerman Martin, 0625040
TODO (original proposal) • Determineparameters • Image size • Radii • Filter outliers • Based on neighborhood • Find suitablefeaturedescriptor • QR-Code reading Android QR-Code Detection, Cerman Martin, 0625040
TODO (what was achieved) • Determineparameters • Image size • Radii • Filter outliers • Based on neighborhood • Find suitablefeaturedescriptor • QR-Code reading Android QR-Code Detection, Cerman Martin, 0625040
Topic & Challenges (what was achieved) Topic • Detectandread QR-Codes on an Android Phone • As definedbythe ISO/IEC Standart • „Set ofblacksquares on a whitebackground“ • Varioussizes (Version 1-40) / Challenges / Goals • Detectionundervariouslightingconditions • Perspectivedistortion • Detectionof QR-Code size • Real-Time Android QR-Code Detection, Cerman Martin, 0625040
Live Demonstration your title
References • [1] Fast Radial SymmetryforDetecting Points of Interest, G. Loy andA. Zelinsky, IEEE Transactions on Pattern Analysis andMachineIntelligence, August 2003 Android QR-Code Detection, Cerman Martin, 0625040