2007 Theo Schouten 1

Fundamentals

•acquisition•processing to an image•models•blob coloring algoritm

2007 Theo Schouten 2

Acquisition and processing

2007 Theo Schouten 3

CCD chips

2007 Theo Schouten 4

CT scan

2007 Theo Schouten 5

MRI scan

•strong magnetic field 1,5 Tesla, alignment of spin of bounded protons, 13C and 31P•electromagnetic pulse, disruption•spin-lattice or T1, and spin-spin or T2 relaxation: EM radiation•3D image after large number of measurements

2007 Theo Schouten 6

Ultrasound

•doppler effect:speed of blood•much technical improvements•also 3D images

2007 Theo Schouten 7

Structured light

2007 Theo Schouten 8

Spot ranger

2007 Theo Schouten 9

CCD focus

passive method:lens is moved until (the center of) the acquired image is as sharp as possible. The average difference between the pixels and their neighboring pixels is used to determine the how sharp the image is.

The active method uses an infrared bundle. The amount of received reflected light is proportional to the distance to the object. With the aid of a motor, the lens is the placed in the appropriate position.

2007 Theo Schouten 10

Image functions

f(x) = f(x,y) the light intensity or energy on position xf(x) = i(x).r(x)f(x) = { fred(x), fgreen(x), fblue(x)}

digitizing modelsaspect ratio’s:1, 4/3 16/9

quantization models: number of bits for light per pixel per color1: binary image8: gray or color imagestrend to higher numbers: 10, 12, 16

2007 Theo Schouten 11

Geometric models

|u| |a11 a12 a23 a14| |X| and x = u/w , y=v/w|v| = |a21 a22 a23 a24| |Y||w| |a31 a22 a33 a34| |Z| |a41 a42 a43 a44| |1|

2007 Theo Schouten 12

Stereo model

2007 Theo Schouten 13

Radiometric models

Energy flux wattsRadiant intensity I= d/d watts/steradianSolid angle (ruimte hoek) d=dA/r2 = dAcos/r2

Irradiance (instraling) E=d /dA watts/m2

Radiance (uitstraling) L=d2/dAcosd

Flux op lens van gebiedje A0 : L dAod = L Ao cos met = /4 D2 cos / (fo/ cos)2

Instraling op Ap : E= / Ap =L A0 cos / Ap Centrum van lens ziet Ap en Ao onder dezelfde ruimte hoek:Ao cos/(fo/ cos)2 = Ap cos/ (fp/ cos)2 Alles in E invullen: E= /4 (D/fp)2 L cos4

2007 Theo Schouten 14

Eye color model

2007 Theo Schouten 15

RGB model

CMY (K)

2007 Theo Schouten 16

Other color models

2007 Theo Schouten 17

Relations, blob coloring

f(xu) f(xl) do:

1 0 color(xc) := color(xu)

0 1 color(xc) := color(xl)

0 0 color(xc) := k ; k := k+1

1 1color(xc) := color(xu) or color(xl)

and store in a list: color(xu) == color(xl)

2007 Theo Schouten 18

Convolution operation

•window (3 x 3)•mask or filter (values of w’s)•convolution: parallel operation•serial operation•for many methods both parallel and serial versions are known