Fwd: how to use Spectral decomposition

[Yasir Yousif]

Hi 

I am performing Spectral decomposition on my 3D seismic, using 15,20,25  frequencies. I display them using RGB blending.but I get images with bad color. How can I enhance the color to make the channels clear.  

With my respect 

Yasir Yousif Fadlelmula

Lecturer of Geosciences 

Red Sea University

Technical Manager of Zat Alemad Mining CO.Ltd 

Tel:+249916516049

[Paul de Groot]

Hi Yasir,

I expect that there is not enough variation in the 3 components you have selected. For a nice display, the components should be complementary. Some people pick frequencies at peaks in the amplitude spectrum, others at double the frequency (e.g. 15, 30, 60). The reasoning for the latter choice is that a doubling corresponds to halving the thicknesses (a layer that brightens in 15 Hz displayed in the red channel is twice as thick as a layer brightening at 30 Hz in the blue channel, is 4 times as thick as the 60Hz in green).

In your case, the spectrum is rather narrow with meaningful frequencies between roughly 15 and 45 Hz. You can try: 15, 30, 45 in red, blue, green. 

Alternatively, you can compute all frequencies between let's say 5 and 75 with steps of 5 Hz. Store these as "Horizon Data". Now load all components in each channel (red, green, blue). Start with a display of red only and use PgUp and PgDwn buttons to scroll through all components. Select one in the lower frequency range that you like. Now do the same with the green channel and select a component in the middle range that shows complementary features to the one shown in red. Finally do the same for the blue channel and select a component in the higher frequency range.

Good luck and best regards,

Paul.

--

Paul de Groot

Special Adviser

-----------------------------------------------------------------------------------------------------------------------   dGB Earth Sciences
Phone: +31 53 4315155 E-mail: paul.d...@dgbes.com Internet: dgbes.com

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[Yasir Yousif]

Thank you for your response.

To view this discussion visit https://groups.google.com/a/opendtect.org/d/msgid/users/CABuvx8HPCr%2BCGjDu-XLaEZh6OgSpfdUMV%2B388_AK93_kfh8Zug%40mail.gmail.com.