2. IMAGE SYNTHESIS 1

3. Image Synthesis Image synthesis operations create images from other images or non-image data Used when a desired image is either physically impossible or impractical to acquire CT-image, CAD, abstract data, image composition, 3D graphics 2

4. Tomography Creates cross-sectional images of solid 3D objects Based on X-ray imaging The technique is implemented by moving an X-radiation source and an x-ray detector in parallel and opposing directions, pivoting about the plane of interest 3

5. Computed Tomography Uses digital computation techniques 2D synthetic cross-sectional image is made of 1D projections CT is vital for medicine 4

6. Computed Tomography Transmissive mode Computed Tomography Based on X-radiation Emissive mode MRI (Magnetic Resonance Imaging) PET( Positron Emission Tomography) Reflective mode radar imaging, ultrasonic 5

7. Examples MRI image, human skull Cross-sectional CT image of human brains 6

8. Examples 2 Cross-sectional images from thorax 7

9. Projections 8

10. 2D Images From Projections (object: a ball) 9

11. Details of CT scanning http://www.impactscan.org/slides/impactcourse/basic_prin ciples_of_ct/img0.html http://www.impactscan.org/slides/impactcourse/basic_prin ciples_of_ct/img0.html 10

12. MRI = Magnetic Resonance Imaging 11 3D image from 2D´s

13. Video on MRI http://www.youtube.co m/watch?v=H5q79R9 C-mk http://www.youtube.co m/watch?v=H5q79R9 C-mk 12

14. 3D Scene Construction From Images Stereo image pairing 13

15. Depth Perception Based on: two eyes, stereo vision (or stereoscopy) relative object sizes object shading and shadowing object obscuring atmospheric haze 14

16. Stereoscopy 15

17. Stereo Image Pair Two images of the same scene with different view angles 16

18. Image Cross-Section Stacking CT and MRI Sequential material removal Confocal laser scanning microscope (material must be transparent) 17

19. Image Cross-Section Stacking Image is shown stacked or sequential 18

20. Volume Rendering Slice-Image Slice-image is two-dimensional and has no depth Convert 2Ds (x,y) into 3D (x,y,z) z is a cross-sectional surface index z is usually coarser than x,y. Intermediate slices are created by interpolation methods Voxel can represent multiple features such as brightness, color and transparency See: http://en.wikipedia.org/wiki/Voxelhttp://en.wikipedia.org/wiki/Voxel 19

21. Example on a voxel image 20

22. Voxels in videos Brain MRI http://www.youtube.co m/watch?v=I4N7wDXV yYg Brain MRI http://www.youtube.co m/watch?v=I4N7wDXV yYg 3D Aorta CT http://www.youtube.co m/watch?v=sy3LH6Z3 Sc4 3D Aorta CT http://www.youtube.co m/watch?v=sy3LH6Z3 Sc4 Kinect User Interface http://www.youtube.co m/watch?v=id7OZAbF aVI Kinect User Interface http://www.youtube.co m/watch?v=id7OZAbF aVI Brain AVM 3D MRI http://www.youtube.co m/watch?v=LonstHwI1 tE Brain AVM 3D MRI http://www.youtube.co m/watch?v=LonstHwI1 tE 21

23. 22

24. Visualization of Non-image Data CAD rendering (computer aided design) Elevation data rendering 3D scanning Visualization of abstract data 23

25. CAD Rendering 24

26. CAD Rendering Methods Wireframe model Hidden-line removal Solid model Tinted solid model 25

27. 3D Rendering In 3D rendering following methods are used: A model is created from sample points A real object is a model A brand new object is created 26

28. 3D Rendering 3D object model can be composed of surfaces, polygons or of a combination of above Surfaces are utilised to render simple objects (balls, sylinders) An arbitary plane can be rendered by using this kind of polygons 27

29. Methods In wireframe polygons can be seen as borderlines In hidden-line removal lines behind the polygons are not drawn 28

30. Methods Solid model rendering Surface and color 29

31. Methods Shaded solid model A surface can also illustrate different materials such as metal or plastic 30

32. Texture and lighting Images we create can look like real when we add different surfaces on them and illuminate them with multiple light sources 31

33. Photo-realistic Rendering Materials, light refraction and reflections 32

34. The Use of 3D Models In scientific research 3D models are used to render objects which are too small, large, fast or slow to be viewed by other ways Examples: atoms, molecules, Explosions etc 33

35. The Use of 3D Models In industry 3D rendering before building an expensive prototype 34

36. The Use of 3D Models Commercial use and entertainment industry Games, movies and TV-programs 35

37. 3D Examples The features of the light can be rendered well, but this requires substantial computing power 36

38. 3D Examples The 3D- models have almost totally replaced the plastic models in the movie industry 37

39. The future of the 3D-graphics Virtual reality? 38

40. Examples of 3D animation Birth 3DDentalPlanning Fertilization 39

41. 40 Elevation data rendering

42. Elevation Model - Reflection planes 41

43. The Calculation of A Reflectance 42

44. 43

45. 44

46. Example of Digital Terrain Model 45

47. 46

48. 47 Visualization of Abstract Data

49. 48