The Edge Finding options allow you to control how Fluid
Mask analyses all or part of your image. When you open Fluid Mask, the
program calculates reasonable values for these options. Sometimes you
may find it helpful to adjust the settings with the goal of finding the
important edges in your image, while at the same time keeping the total
number of objects as small as possible.
The settings you make on the main Edge Finding palette
apply to the entire image. However, sometimes different areas of an image
have such varied characteristics that it is difficult to find settings
that work for the entire image. To solve this problem, you can create
a patch over part of an image using the Patch
tools and apply a unique set of edge finding options to just that area
using the Patch Properties dialog.
The edge finding settings all change the number and size
of the objects Fluid Mask will detect in an image. In general, the best
way to dial in the optimum settings is to start with the default settings
and then work from top to bottom of the Options Palette. In other words,
find the best edge width threshold first, then the best setting for the
number of objects, and so on.
- Edge Width Threshold:
sets the minimum width in pixels of a color or texture transition that
Fluid Mask will recognize as an edge. If you set a small threshold, Fluid
Mask will find many in-focus and sharp edges; if you set a larger threshold,
Fluid Mask will find fewer but broader edges such as found with out of
- Number of Objects:
Sets how finely Fluid Mask divides an image into objects. The higher
the setting, the more objects Fluid Mask will identify.
When working with fine detail like tree leaves and branches, move the
slider all the way to the right – this is the optimal setting for finding
these kinds of objects. You will note that the Show
Object Edges check box at the bottom of the screen has been turned
off at this setting, as indicating such fine objects is not useful.
- Defaults button:
Restores the edge detection settings to the original, calculated values.
- Revert button:
Restores the edge detection settings to the last settings you applied.
- Apply button:
Applies the current settings and re-analyzes the image.
Click the Advanced button to reveal
the advanced options. These options do not need to be adjusted for most
- Edge Contrast:
Sets how much difference in color there must be for an edge to be identified.
- Choose Low
to have Fluid Mask identify low contrast changes as an image edge.
Medium or High
when there is plenty of contrast between the image to be cut out and the
background. A higher setting will result in fewer edges —
useful for complex images..
- Filter out Texture:
Sets how Fluid Mask should combine highly textured areas.
- Choose Fine
to have Fluid Mask treat each object within a textured area separately,
such as when you are cutting out leaves against the sky.
- Choose Coarse
to have Fluid Mask treat textured areas as a single area, such as when
you want a lawn to be treated as a single object with one edge rather
than as several small objects with many edges.