Tips

March 2003 - Issue 17

05.  TECPLOT TIPS - IMPORTING FREQUENCY DATA & IMAGE ANALYSIS

With the availability of CCD cameras, more data than ever is generated as image files. In this example we load an image into Tecplot perform simple data analysis. In addition, we learn about single variable zones in Tecplot.

Our original image is a transmission electron microscopy (TEM) bitmap. The TEM image was created by placing a very high energy electron beam on a thin, partially electron-transparent silicon wafer, then recording the electron shadow with the CCD camera. TEM imaging allows for magnifications up to 1,000,000 times, and very high-resolution imaging, with point-to-point resolution of better than 2 nm.

The original TEM bitmap image.

Step 1: Converting the TEM Image to Text

1. Open the TEM scan image (TEM_scan.bmp 1,424 KB) with a graphics application.
(In this example, we use ImageJ — a free program that can be downloaded here .)

2. In the upper left corner, ImageJ displays image resolution. This information is needed for header details in Step 2

3. Crop the image to minimize the amount of black. The image is now 692 x 296 pixels.

4. Save as a text image — TEM_scan.txt .

Step 2: Adding Header Information and Loading into Tecplot

1. Open the TEM_scan.txt file with a text editor. The text file contains a large number of intensities.

2. Add header info to the text file.
3. Variables = "INT" (intensity is the only variable).
4. Zone I = 692, J = 296 (pixel height x width).
5. Save the file.

6. With Tecplot, load TEM_scan.txt .

Click here for Step 2
(In Step 2 we perform some basic data analysis.)

Product Reviews