CRImage (version 1.20.0)

calculateOtsu: Does Otsu thresholding

Description

The function applies Otsu thresholding on the image.

Usage

calculateOtsu(allGreyValues)

Arguments

allGreyValues

Vector of grey values.

Value

the threshold

Details

The function calculates a value which separates the grey value histogram the best in foreground and background.

References

Nobuyuki Otsu: A threshold selection method from grey level histograms. In: IEEE Transactions on Systems, Man, and Cybernetics. New York 9.1979, S.62-66. ISSN 1083-4419

See Also

calculateThreshold localOtsuThreshold

Examples

f1= system.file("extdata", "exImg2.jpg", package="CRImage")
print(f1)
img=readImage(f1)
print(img)
#convert to grayscale
imgG=EBImage::channel(img,'grey')
#threshold value
t=calculateOtsu(as.vector(imgG))