Soft Imaging System ColorView III, Руководство пользователя

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Display and usage of the acquisition with Real time FFT
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Enabling Real time FFT Real time FFT can be activated in the input channel. To do this, select the
Image > Configure input > Display > Real time FFT dialog box.
Real-time Fast Fourier Transformation (RTFFT) calculates the acquired im-
age's Fourier image in real time (the absolute value of the Fourier trans-
forms). The Fourier image is continually updated during a live acquisition. It
can serve as a quantitative display of the image quality. For example, if you
blur the microscope image, the high frequencies disappear in the Fourier im-
age (i.e. the structures which are located farther away from the center).
The Fourier Image of a Cat-
alase 2-D Crystal.
The points represent period-
ic structures in the micro-
scope image. The closer
such a point is to the center,
the smaller the spatial fre-
quency of the correspond-
ing periodic structure, i.e.
the larger the periodic dis-
tances in the microscope
image. (The cross arises
due to fringe effects.)
To achieve optimum on-screen display of the fourier image, use the RTFFT
Control dialog box with the tabs ROI ,Display , and Tools .
ROI Use the ROI tab to select the region, the RTFFT is executed on. The RTFFT
is calculated on a square part of the image. Two different sizes are available
for the calculation. You can also freely position the square to be analyzed in
the image.
Note In case the offered sizes are still too small, you can activate binning. This
increases the size of the ROI compared to that of the image section.
256x256, 512x512 Select the option 256x256 or 512x512 to make the ROI the respective size.
Show ROI Select the Show ROI check box to display the position of the ROI in the live-
image. The ROI is displayed as a red frame.