Threshold Type

This option specifies how the thresholds defining the particles are to be determined. The thresholds may either be set in advance by the user, or determined automatically for each image processed based on the intensity histogram of that image. In most situations manually choosing the thresholds in advance will produce better results, however for inexperienced users or for flows where the overall brightness of the images change with time, then automatic thresholding may be preferable.

Specify Fixed thresholds in advance or determine them Automatically ?

Choosing <F> allows access to [T Lower threshold], [U upper threshold] and [V Number of threshold levels] through which the user may specify the thresholds used to determine the locations of the particles. If <A> is selected, then the threshold is determined automatically from the intensity histogram in each image processed.

Parent menu

Main Menu

DigImage User Documentation

Stuart Dalziel, last page update: 19 February 1996