Home Cell Biology Threshold Calibration
Steps
  1. 1 Introduction & purpose --:--
  2. 2 Select calibration images 00:10
  3. 3 Run calibrateThreshold macro in Fiji 00:46
  4. 4 Inspect mask outputs 01:30
  5. 5 Run EvaluateCalibration.R in RStudio 01:55
  6. 6 Choose final threshold value 02:25
Cell Biology Bio-protocol Video Citable · DOI

Threshold Calibration

DOI: 10.21769/BioProtoc.v270
Protocol

Practical demonstration of threshold calibration in autophagy image analysis using Fiji macros and an R evaluation script.

Difficulty
beginner

Steps

1
Introduction & purpose

Explains why threshold calibration matters for vacuole selection in image analysis.

▶ --:--
2
Select calibration images

Locate processed TIFF files; copy one good, one average, one poor scan into a "calibration" folder.

▶ 00:10
3
Run calibrateThreshold macro in Fiji

In Fiji: Plugins → Macros → Run → Autoflux/imageJ macro/calibrateThreshold.Igm. Point at the calibration folder.

▶ 00:46
4
Inspect mask outputs

For each input image the macro writes a series of masks back into the calibration folder, plus an overview TIFF.

▶ 01:30
5
Run EvaluateCalibration.R in RStudio

Open EvaluateCalibration.R → Code → Source → choose the calibration folder to generate ThresholdGraph.tiff.

▶ 01:55
6
Choose final threshold value

Combine the ThresholdGraph with the masks to pick an upper threshold; the demo lands on a value of 3.

▶ 02:25
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