NIH Image

Analyze Particles automatically counts and measures objects in binary or thresholded images. It does this by scanning across the image until it finds the boundary of an object, outlines the object using the same outlining routine used by the wand tool, measures the object using the equivalent of the Measure command, and then redraws the object in a different gray level so that it becomes invisible to the scanning process. Use Show Results to display the recorded measurements. Up to 32767 particles can be counted, but measurement recording is limited to the first Max Measurements (set in the Options dialog box) particles. Hold down the option key to bypass the dialog box. Use command-period to abort particle analysis. Particles smaller than Min Particles Size or larger than Max Particle Size will be ignored. Note that the sizes must be specified in pixels. Checking Label Particles causes Analyze Particles to draw a number, corresponding to the measurement number, on each particle found. Check Outline Particles if you want particles to be outlined (this currently only works for density sliced images). Checking Ignore Particles Touching Edge causes Analyze Particles to ignore particles touching the edge of the image. Interior holes in area and mean density computations are included if Include Interior Holes is checked.