Minimum Average Intensity Excess

In addition to satisfying the threshold criteria specified by [T Lower threshold] or [U Upper threshold], a particle will generally have an average intensity which exceeds this threshold by some amount. The entry specified by this option sets a lower limit on how much the average intensity must exceed the threshold by. If this limit is not satisfied, then the "blob" in the image will not be considered a particle.

Minimum difference between average particle intensity and threshold ?

As the average intensity is not confined to integer values, the minimum difference may take non integer values. Choice of the difference depends on the quality of the images being tracked, and the available contrast. Generally a nonzero value should be given so that the particles are forced to more than just satisfy the threshold. This is also desirable in order to ensure subpixel accuracy for specifying the particle location.

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Stuart Dalziel, last page update: 19 February 1996