Opacity in 3D projections

[Knecht, David]

I find the description of "Opacity" in the 3D project menu opaque:

 "Opacity Can be used to reveal hidden spatial relationships, especially on overlapping objects of different colors and dimensions. The (surface) Opacity parameter permits the display of weighted combinations of nearest-point projection with either of the other two methods, often giving the observer the ability to view inner structures through translucent outer surfaces. To enable this feature, set Opacity to a value greater than zero and select either Mean Value or Brightest Point projection."

Can someone translate this into something taht explains how you would actually use it to reveal inner structures? I don't understand what the weighting is and how it would be combined with other projections.  Thanks- Dave

David Knecht, Ph.D.
Professor and Head of Microscopy Facility
Department of Molecular and Cell Biology
U-3125
91 N. Eagleville Rd.
University of Connecticut
Storrs, CT 06269
860-486-2200
860-486-4331 (fax)





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[Glen MacDonald-2]

HI David,
Open the bat-cochlea sample image and compare 0% and 50% for opacity and depth cueing singly, then both together for a MIP rotation.  Set both to 0% and the brightest intensities along the computed viewing angle prevail. Visual cues regarding interior structures (often of lower intensity) and depth of the volume are lost.    Raising the interior depth cueing provides an intensity gradient according to depth from the viewing surface.  Elevating Opacity seems to reduce the opacity of near structures to allow viewing intensities computed as being further away from the viewer.  This can bring out a greater sense of depth and the relationship between the surface and interior structures of a volume.
Switching to the Fire LUT may assist visualizing the effects.  Hope this helps.  
Glen MacDonald
        Core for Communication Research
Virginia Merrill Bloedel Hearing Research Center
        Cellular Morphology Core
Center on Human Development and Disability
Box 357923
University of Washington
Seattle, WA 98195-7923  USA
[phone]
[hidden email]
[hidden email]





On Mar 14, 2013, at 9:12 AM, "Knecht, David" <[hidden email]> wrote:

> I find the description of "Opacity" in the 3D project menu opaque:
>
> "Opacity Can be used to reveal hidden spatial relationships, especially on overlapping objects of different colors and dimensions. The (surface) Opacity parameter permits the display of weighted combinations of nearest-point projection with either of the other two methods, often giving the observer the ability to view inner structures through translucent outer surfaces. To enable this feature, set Opacity to a value greater than zero and select either Mean Value or Brightest Point projection."
>
> Can someone translate this into something taht explains how you would actually use it to reveal inner structures? I don't understand what the weighting is and how it would be combined with other projections.  Thanks- Dave
>
> David Knecht, Ph.D.
> Professor and Head of Microscopy Facility
> Department of Molecular and Cell Biology
> U-3125
> 91 N. Eagleville Rd.
> University of Connecticut
> Storrs, CT 06269
> 860-486-2200
> 860-486-4331 (fax)
>
>
>
>
>
> --
> ImageJ mailing list: http://imagej.nih.gov/ij/list.html

... [show rest of quote]

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