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Préparation d'une pile d'images pour des mesures automatiques

A partir du mode d'emploi du module (plugin) Tracker

Téléchargez la pile d'images d'exemple pour vous faire la main

Lien vers le plugin

Raw-stack.tif is a movie showing two termites running around in a petri dish. To use the Tracker plugin, all the images in the stack must be thresholded so that the termites are black and everything else is white.

1) Use Image/Duplicate to make a copy of the first slice in the stack. Name it "background".

2) Remove the two termites from the background image. For each termite, copy one or more small rectangular background selections and paste them over the termite. Use the magnifying glass tool to zoom in, type C to copy, the arrow keys to move the selection one pixel at a time, and type V paste.

3) Use Process/Image Calculator to subtract the background image from all the images in the stack. In the dialog, "Image1" is the stack, "Operator" is "Subtract" and "Image2" is the background image. Note: you will see a message that says "Process all 1 slices?". What it should say is "Process all 50 slices?". This is fixed in v1.19z.

4) Use Process/Smooth to blur all the images in the "Result" stack.

5) Use Image/Adjust Threshold (shift-t) to adjust the upper and lower thresholds so the termites are red and background is black. Scroll through the stack to verify that all the termites are in one piece and there no stray red pixels. Adjust the threshold levels if necessary.

6) Click the "Apply" button in the "Thresold" window to convert all the images in the stack to binary (black and white). This will not work if the drawing color is not black. The threshold tool in v1.19z has an option that forces the drawing color to be black.

7) Run the Tracker plugin.

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Page last modified on March 29, 2011, at 10:06 AM