Working with the preprocessing pane
Tip: | The preprocessing pane is not shown in the
default layout. Use the Window menu to show
it. |
The preprocessing pane is rarely used, and exists only to allow fine tuning
of the underlying algorithm used to detect colours. This is
a stochastic algorithm, meaning that it may produce slightly
different results each time, although generally this will not be noticeable
to the naked eye. You may occasionally, however, see slightly different
colours selected, even for the same photo and same settings.
Care should be taken when adjusting the first two of these settings in
particular, as large values may make the program unresponsive.
- Reps sets the number of times the algorithm is run. The
best result from all runs is then used. Increasing this may improve both the
quality and consistency of colour detection. It will increase runtime when
clusters are added or removed, but not at other times.
- Pixels sets the number of pixels used for colour
detection. Approximately this many pixels are subsampled from the
image. Increasing this may improve the quality and consistency of colour
detection, particularly when attempting to select small regions of
colour. It will increase runtime when clusters are added or removed, but not
at other times.
- Threshold sets the minimum saturation value of a pixel for it to
be considered in colour detection. Adjusting this may improve the quality of
colour detection in some situations, particularly where the detection of
very bold colours in the image is sought, and less saturated pixels appear
to be detracting from the final result.