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Context… Capture
Particle Capture
Distance to Nearest Neighbor
- Any particles that are equal to or less than this distance in microns
from each other will be imaged as one particle when the software analyzes a raw camera image and
segments out particles. Increasing this value will increase the chances that separate, unique particles
will be erroneously imaged and counted as one particle (not as multiple particles). It is recommended to
leave this set at zero (0).
Close Holes (iterations)
- Closing holes is a standard morphological operation used to fill in small gaps
in an image. The operation is performed on the thresholded binarized camera image after the
background has been removed. Each iteration of the close holes operation consists of a dilation and then
an erosion of the image using a 3x3 pixel neighborhood. For each neighborhood, the process is as
follows:
·
Dilation:
if any of the center pixel's neighbors are white (considered part of a particle in the
thresholded image), then the center pixel is set to white as well, otherwise it retains its current
value.
·
Erosion:
if any of the center pixel's neighbors are black (not considered part of a particle), then
the center pixel is set to black as well, otherwise it retains its current value.
The close holes operation is repeated as many times as selected by Close Holes (iterations). The result
of closing holes is to fill in small areas of an image that may have been lost due to a threshold setting
being too high or the particle image being too faint. Be aware that repeated iterations can distort the
original image. To check the effects of increasing the Close Holes iterations, enable the Save Binary
Collage Images setting (see the relevant section below for more information) and review the binary
collage images.
