STEP-BY-STEP INSTRUCTION FOR EXAMPLE F (Insect Motion Edition only)

This is an example that shows how to use a background mask technique to improve the image pattern tracking (IPT) results. A group of images were acquired with a high speed imaging system at a frame rate of 3000 fps to capture the head bang motion of a termite. This image group includes 300 frames, and a ruler image (6mm resolved with 305 pixels) is used to determine the object to image ratio.

 

Step 1: Create image file list

- Execute file “Edpiv.exe” - The start window is shown on the screen;

- Select menu “Edit \ File list” - Dialogue box “Creating file list” appears;

- Press “Input files” button - Dialogue box “Data file list” appears;

- Browse hard drives to find folder “…\PIVsamples\ f_BackgroundMask”;

- Arbitrarily select one of the Windows Bitmap (BMP) files in the folder;

- Press “Open” button - Dialogue box “Data file list” is closed;

- Press “Output file” button - Dialogue box “Data file list” appears again;

- Browse the hard drives to find a destination folder;

- Type a name for the file list in the edit box indicated by “File name”;

- Click “Save” button - Dialogue box “Data file list” is closed;

- Press button “Create” to generate the image file list;

- Close the dialogue box to return to the start window.

Step 2: Open the image group

- Click menu “File \ Import image group” in the start window - Dialogue box “Recording group” appears;

- Browse the file system to find the image file list created in step 1;

- Click “Open” - The first frame of the image group is shown in the window.

Step 3: Input imaging scale and time interval

- Click menu “Edit / Scale & time” in the start window to open dialogue box “Imaging scale / time interval”;

- Input 6 in edit box “Reading on ruler [mm]”;

- Input 305 in edit box “Corresponding pixels”;

- Input 333.33 in edit box “Time interval [mu-s]”;

- Press “OK” button to return to start window.

Step 4: Tracking an image pattern and save the data

- Press button “Evaluation” in the start window;

- Click menu “Start” in “Evaluation” window;

- Select parameters in dialogue box “Evaluation settings” as
Method & algorithm:
Image pattern tracking (IPT)
Tracking freedom limit: 1
Image pattern diameter: 32

- Press “OK” in “Evaluation settings” box;

- Move the mouse to select image pattern at (51,63) and then click the left mouse button;

- Set “end frame” number t0 300 and press  button “OK”;

- Wait until the image pattern tracking is finished;

- Click menu “Edit \ Display time history \ Displacement” to display the displacement time histories in the window;

- Click menu “Edit \ Save” to save the displacement time histories in a file;

- Close “Evaluation” window.

Step 5: Paste background image

- Press “Processing” in the start window to open “Image processing” window;

- Click menu “Edit \ Image memory \ Save” to save current image (the 1st in the group) into the image memory;

- Type image number 70 into the edit box, so that the image saved in the memory is shown as red color, whereas the current image (the 70th) shown as cyan color;

- Click menu “Edit \ Create image \ Paste” to open dialogue box “Filter settings”;

- Input Rx=24, Ry=16 in dialogue box “Filter settings”, and then press “OK” button to activate the mouse function for background image pasting;

- Move the ellipse frame to select the background of current image, and then press the left mouse button to paste it to the background image saved in the image memory;

- Repeat the background image pasting several times to minimize the red color region in the background of the current image;

- Press “TJ” button to close the mouse function.

Step 6: Select background mask parameters

- Click menu “Edit \ Background mask \ setup” to show buttons “Mask”, “-“, “OK” and “+”. The background mask effect is shown in the window;

- Type image number 1 into the edit box;

- Press button “Mask” to select background mask type “a”, i.e. use both bright and dark image pattern;

- Press button “-” or “+” to reduce or increase the background mask effect;

- Press “OK” button to complete the background mask setup;

- Close “Image processing” window.

Step 7: Tracking an image pattern with background mask

- Press button “Evaluation” in the start window to open “Evaluation” window;

- Click menu “Start” in “Evaluation” window;

- Select parameters in dialogue box “Evaluation settings” as
Method & algorithm:
Image pattern tracking (IPT)
Functions: BG mask selected
Tracking freedom limit: 1
Image pattern diameter: 32

- Press “OK” in “Evaluation settings” box;

- Move the mouse to select image pattern at (51,63) and then click the left mouse button;

- Set “end frame” number t0 300 and press  button “OK”;

- Wait until the image pattern tracking is finished;

- Click menu “Edit \ Display time history \ Displacement” to display the displacement time histories in the window;

- Click menu “Edit \ Save” to save the displacement time histories in a file;

- Close “Evaluation” window.

Step 8: Make plots with TECPLOT software

- Close EDPIV;

- Use TECPLOT to make plots.

 

Results: Image pattern tracking without background mask

 

Results: Image pattern tracking with background mask