1. Improving Image registration accuracy Narendhran Vijayakumar 02/29/2008

2. Outline Results – Radial diffusion modality better than DWEPI Improving Image Registration accuracy – Using K means clustering 2

3. Result1 3

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8. Improving Registration Accuracy Increasing histogram bin width 1 – Results in increased Accuracy – Achieved using K means clustering – Classifies objects based on object’s attribute Algorithm – Randomly places a object in each of K clusters – Euclidean distance between the centroid and each object is calculated – Objects placed in groups based on the distance 8 1 Knops et al., Normalized mutual information based registration using k-means clustering and shading correction, Medical Image Analysis, 2006

9. Flowchart 2 9 Choose K Calculate Centroid Euclidean Distance Group based on minimum distance Any change in groups Start End Yes No 2 http://people.revoledu.com/kardi/tutorial/kMean/index.html

10. Challenges – The number of cluster, K, must be determined before hand – Large variance in a cluster may lead to incorrect mean value Overcoming the challenges – Use median instead of mean – Determine ‘K’ based on image properties 10