2 # Subspace Identification Extension to the Phase Correlation Method (SIE-PCM) demo
4 This short bit of Matlab code was the original implementation of the method described in
5 ``A subspace identification extension to the phase correlation method,''
6 IEEE Trans. Medical Imaging, 22(2):277-280, Feb. 2003.
7 http://dx.doi.org/10.1109/TMI.2002.808359
9 Images from the original 5 test frame data are included as well.
13 run_example.m - start here
14 siepcm.m - a function to estimate the row and column translation between two images
16 The images are from 5 different MRI acquisition of a grapefruit, with
17 the grapefruit at different locations within the field-of-view. In
18 the table below, the coordinates of one corner of the field of view
21 Image File | Source file | dim1 loc | dim2 loc
22 ------------|-------------|--------------|------------
23 img1.png | P64512.7 | y = 8.30 cm | z= 2.00 cm
24 img2.png | P00000.7 | y = 8.15 cm | z= 2.25 cm
25 img3.png | P00512.7 | y = 8.00 cm | z= 2.50 cm
26 img4.png | P01024.7 | y = 7.85 cm | z= 2.27 cm
27 img5.png | P01536.7 | y = 7.85 cm | z= 2.75 cm
29 To determine the expected translational shift between the images, use the
30 difference between the coordinates divided by the distance per pixel.
32 dy = (y2 - y1) / n where n=0.0625
34 The original data was acquired on a GE Signa Lx 1.5T MR Scanner using
35 the following parameters:
36 TR: 500 TE: 15 protocol: FSE coil: HEAD
38 ----------------------------------------------------------------------
40 FOV length : Image Size :: 160mm : 256 pixels; => 0.0625 mm/pixel
42 compare images 1 and 2. S: -2.5 mm, A: 1.5 mm
43 expect z = -4.0000, y = +2.4000
45 compare images 1 and 3. S: -5 mm, A: 3 mm
46 expect z = -8.0000, y = +4.8000
48 compare images 1 and 4. S: -2.7 mm, A: 4.5 mm
49 expect z = -4.3200, y = +7.2000
51 compare images 1 and 5. S: -7.5 mm, A: 4.5 mm
52 expect z = -12.0000, y = +7.2000
54 compare images 2 and 3. S: -2.5 mm, A: 1.5 mm
55 expect z = -4.0000, y = +2.4000
57 compare images 2 and 4. S: -0.2 mm, A: 3 mm
58 expect z = -0.3200, y = +4.8000
60 compare images 2 and 5. S: -5 mm, A: 3 mm
61 expect z = -8.0000, y = +4.8000
63 compare images 3 and 4. S: 2.3 mm, A: 1.5 mm
64 expect z = +3.6800, y = +2.4000
66 compare images 3 and 5. S: -2.5 mm, A: 1.5 mm
67 expect z = -4.0000, y = +2.4000
69 compare images 4 and 5. S: -4.8 mm, A: 0 mm
70 expect z = -7.6800, y = +0.0000
72 ----------------------------------------------------------------------
74 Copyright 2003, W. Scott Hoge (wsh032580 at proton dot me)
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