Otsu's method

Last revised by Joachim Feger on 7 May 2024

Citation, DOI, disclosures and article data

Citation:

Moore C, Feger J, Otsu's method. Reference article, Radiopaedia.org (Accessed on 18 May 2024) https://radiopaedia.org/articles/188842

DOI:

Permalink:

https://radiopaedia.org/articles/188842

rID:

188842

Article created:

5 May 2024, Candace Makeda Moore

Disclosures:

At the time the article was created Candace Makeda Moore had no financial relationships to ineligible companies to disclose.

View Candace Makeda Moore's current disclosures

Last revised:

7 May 2024, Joachim Feger ◉

Disclosures:

At the time the article was last revised Joachim Feger had no financial relationships to ineligible companies to disclose.

View Joachim Feger's current disclosures

Revisions:

2 times, by 2 contributors - see full revision history and disclosures

Otsu’s method, also known as Otsu's threshold algorithm, is an automatic thresholding algorithm used in image processing.

The method separates pixels or voxels from an image into groups based on where their values lie in relation to the image histogram. The method finds threshold values that create a separation to minimize intraclass pixel/voxel value variance or conversely, maximize the interclass variance of values.

Many image processing libraries have built-in implementations (pre-made functions) of Otsu’s method that will return the threshold value computed with this method and there are many variations and extensions of Otsu’s method that have been applied to radiological images ^2,3.