[Users] Transparency / Opacity in OpendTect

[Arnaud Huck]

Dear OpendTect users,

Of of our users asked me the following questions: is it possible to 
see/analyze the amplitude histogram in the visualization tool? Or for 
instance, apply an opacity filter to display only certain amplitude values?

Let me answer to this questions. Yes, this is possible in OpendTect:
First, you need to have access to the amplitude histogram; This is 
achieved by selecting the attribute in the tree scene, moving the cursor 
over the colorbar, right-click and press edit. This will pop-up the 
colourbar editor, which always shows the histogram of the selected 
attribute in grey on the top right corner of this window. The X-label of 
this histogram is represented by the amplitudes shown on either sides of 
the colourbar in the main window.

Now that you have access to this histogram, you can apply an opacity 
filter by adding nodes where the histogram is shown. This transparency 
function as we call it is displayed using a red line joining the nodes 
(two nodes are always present, although they can move up and down). The 
more the transparency (red) curve is to the top, the less the 
corresponding colour will be shown. As many nodes as needed can be added 
with a double click. The result of any editing will be applied directly. 
There is no need of going out of the colour bar editor.

Please note that some default colorbars (like Chimney) already have a 
transparency function integrated.

We are currently developing a more sophisticated histogram tool, which 
is available in our development release 3.1.4a 
(http://download.opendtect.org). A specific button "Show histogram" is 
available in the menu when making a right-click on an attribute in the tree.

Best regards,
Arnaud.

-- dGB Earth Sciences B.V.
-- Nijverheidstraat 11-2, 7511 JM Enschede, The Netherlands
-- mailto: arnaud.huck at dgb-group.com, http://www.dgb-group.com
-- Tel: +31 53 4315155 , Fax: +31 53 4315104