７
APPENDIX
7.4.2d WinSPM
image file
［
3
］
(FFT image file)
The following describes the FFT image file data structure.
In the FFT image file, the SPM Image data structure (Normal Image Data section)
precedes FFT calculation results
（
FFT data
）
. The FFT spectrum is recorded as a TIFF
image.
■
FFT image file data structure
The data structure up to the FFT data recording section in the FFT data structure is
identical to that of the SPM image file data. The FFT data structure, however, contains
FFT data that correspond to each point of the normal image data and the real part and
imaginary part of complex numbers in the data are floating-point.
•
FFT data recording structure: complex8
0x0000
Normal Image Data
Normal Image Data Size
EOF
FFT Data
Type
Size
Note
float 4
bytes
Real part
float 4
bytes
Imaginary part
The FFT data size of a 512
×
512 pixel FFT image is {real part
（
4 bytes
）
+ imaginary part
(4 bytes) }
×
512 pixels
×
512 pixels = 2,097,152 bytes.
■
Overall file size
The size of the FFT image file is the normal image data size (531,412 bytes) + FFT data
size (2,097,152 bytes) = 2,628,564 bytes.
7-46
TMPM5200-2
