1. 12 mhj/ 16-06-20041 Optimal Color Representation of Multi Spectral Data M.L.H. van Driel s462760 Supervisors: P. Sereda Prof. B.M. ter Haar Romeny

2. 12 mhj/ 16-06-20042 Contents Introduction Artherosclerotic plaques Color Models –RGB –HSV –CIE Lab Methods & Results Conclusions Discussion Recommendations

3. 12 mhj/ 16-06-20043 Introduction From gray scale to multi spectral color images should improve the possibilities for tissue recognition and classification. Examples are multi spectral MRI measurements for artherosclerotic plaque classifications in medium and large arteries.

4. 12 mhj/ 16-06-2004S.v.d.Ven (2004)4 Artherosclerotic plaques Stable – Vulnerable Important tissues –Calcification –Fibrous tissue –Hemorrhage –Lipid –Lumen

5. 12 mhj/ 16-06-20045 Color Models RGB (Red Green Blue) HSV (Hue Saturation Value) CIE Lab (Commission Internationale d`Eclaraige Lab)

6. 12 mhj/ 16-06-2004http://www.bodoni.co.uk/colourwor kshop.html 6 Color Models - RGB Primary colors Range 0-255 (0-1) Device dependant

7. 12 mhj/ 16-06-2004http://www.ncsu.edu/scivis/lesson s/colormodels/color_models2.html 7 Color Models - HSV Hue: color Saturation: dominance of hue Value: lightness – darkness Range (0-1)

8. 12 mhj/ 16-06-2004http://www.colourware.co.uk/cpfaq /q3-21.htm 8 Color Models – CIE Lab L – Lightness (0-100) a – green red (-/+100) b – blue yellow (-/+100) Device independent Difference between 2 colors in the Lab space is an indication of the contrast

9. 12 mhj/ 16-06-20049 Methods & Results Input –Matching –Histogram Equalization The Optimal Color Model and Configuration

10. 12 mhj/ 16-06-200410 Methods & Results - Input 8 sets of 5 images with 3 tissues classified –T1 weighted (2D) TSE (1) –PD weighted TSE(2) –T1 weighted (3D) TFE(3) –Partial T2 weighted TSE(4) –T2 weighted TSE(5)

11. 12 mhj/ 16-06-200411 Methods & Results - input Matching –Same regions in different images should have the same locations Histogram Equalizing

12. 12 mhj/ 16-06-2004*http://www.cs.rit.edu/~ncs/color/t _convert.html 12 Methods & Results – The Optimal Color Model and Configuration Comparing the different Color Models –Converting RGB and HSV to CIE Lab * Calculating the distances between the tissues

13. 12 mhj/ 16-06-200413 Methods & Results – The Optimal Color Model and Configuration Red = CIE Lab Green = RGB Blue = HSV

14. 12 mhj/ 16-06-200414 Methods & Results – The Optimal Color Model and Configuration Maximum of the minimal distance –Cut off 30

15. 12 mhj/ 16-06-200415 Methods & Results – The Optimal Color Model and Configuration Good configurations? the configurations {{3,1,2},{3,2,1},{5,2,1},{5,1, 2}} were found within the boundary conditions in 7 out of 8 cases (all within the Lab Color Model)

16. 12 mhj/ 16-06-200416 Conclusions To distinguish just arbitrary tissues CIE Lab is an appropriate Color Model In specific cases there can be better settings (in CIE Lab or even HSV) than in the arbitrary case RGB should not be considered an option

17. 12 mhj/ 16-06-200417 Discussion No Golden Truth “Cut off 30” at least questionable Histogram Equalization? Other input

18. 12 mhj/ 16-06-200418 Discussion Histogram Equalization Filters

19. 12 mhj/ 16-06-200419 Discussion – other inputs

20. 12 mhj/ 16-06-200420 Recommendations 5D instead of 3D input Differentiate for distinguishing different tissues Alternative for Histogram Equalization Other inputs

21. 12 mhj/ 16-06-200421 Thanks Petr Sereda Bart ter Haar Romeny Woutjan Branderhorst Martin Knýř