1. Image segmentation Grey scale image Binary image 34 19 12 13 18 55 2156 11 31 14 10 15 54 33
Threshold range
20-255 1 1 1 1 1 1 1 1 1

2. But simpler to interpret:
8-bits
Binary image
1-bit
Labelled objects
Less information
But simpler to interpret:
46 objects with different properties (size, shape, intensity, …)
65536 pixels
Intensity range 0-255
A lot of information !

3. Segmentation exercises
Open Samples>Blobs
How to determine the threshold?
Manual (use histogram and line profile for help)
Automatically
Remove “noise” with filters before applying segmentation

4. Edge detection Process>Find edge Open Samples>Blobs
Uses a Sobel edge detector to highlight sharp changes in intensity in the active image or selection
Open Samples>Blobs
Detect the edges
Apply a Gaussian Filter then detect the edges

5. Color thresholding
Thresholds 24-bit RGB images based on Hue Saturation and Brightness (HSB), Red Green and Blue (RGB), CIE Lab or YUV components.
Great method to extract DAB signal from histological stains
Image>Adjust>Color Thresholding
Open Samples>Fluorescent cells
Open BrdU-PCNA