Tech Battles: Colourscale vs Greyscale Which is best for viewing seismic data?

Seismic You Can Trust presents: TECH BATTLES

What is the most common response a geophysicist gives to any technical question? 

“It depends”

Frustrating? Absolutely. BUT the right answer usually does depend. On the geology. The objectives. The acquisition. The processing. The compromises you're willing to make. Turns out, that's not a very satisfying answer... so we're going to argue about it instead.

Our geophysicists like to argue (don’t worry, MS Teams prevents any fisticuffs). Most of those arguments make our work better and help us deliver Seismic You Can Trust. So we decided to take some of the debates we have every day, make them (slightly) more public friendly, and film the whole thing for your entertainment.

For our first Tech Battle we ask... Which is better for viewing seismic… Colour or Grey scale?

This question seems to provoke many into offering their opinion. Does it really depend, or is one superior to the other? Is it only geologists who prefer colour? 

Watch the hotly anticipated inaugural Tech Battle with Tas Burn and Connor Boylan and let us know who you think is the winner.

Don’t let Connor sway you with what happens at the end of this video, he is just showing off. The full transcript can be found below the video:

https://www.youtube.com/watch?v=weKgr5BN1BE

ROUND 1 – Which Is Better for Processing QC?

TEAM COLOUR

QC isn’t about making the seismic look its best, it's about finding what's wrong with it.

Colour separates amplitudes much more clearly because you end up with two levels of intensity. Which is much better at showing subtleties in amplitude differences.

If we're QC'ing adaptive subtraction, random noise attenuation or eraser strikes from an overly aggressive demultiple, colour makes those problems jump out.

Why would we deliberately choose a display that makes processing problems harder to find?

TEAM GREYSCALE

I'll give you random noise, but what about linear noise? Coherency? Deghosting?

Those are all easier to judge in greyscale.

Before the broadband revolution, colour worked well because we were looking at a much narrower frequency range.

But for the past 15 years, greyscale has been the best way to see the low frequencies we've worked so hard to recover.

If your colour map goes through white, you’re recovering the full bandwidth… then hiding part of it!

Madness.

TEAM COLOUR

Nonsense!

Anyway you've just proved our point. Greyscale became popular because broadband looks better in greyscale. QC isn't about making the data look good, it's about exposing faults in the data.

TEAM GREYSCALE

You're absolutely right. It is better at finding faults... really steeply dipping ones that become crystal clear once you've recovered all those lovely low frequencies.

Oh... you meant processing faults.

TEAM COLOUR

Very funny.

ROUND 2 – Which Is Best When Showing Clients Your Results?

TEAM COLOUR

This one's easy. Show clients the data the way they actually use it.

We've worked with clients who wanted everything shown in colour - so we used it throughout the project. The last thing you want is to deliver your seismic, the client switches to colour and immediately spots something you missed.

That's an embarrassing conversation.

TEAM GREYSCALE

Where’s your backbone?

If we've tested every processing decision in greyscale... that's how we should present it.

We're showing exactly what we based our decisions on.

If our processing has genuinely improved bandwidth & continuity, greyscale should prove it. And – did I mention it’ll look great?!

TEAM COLOUR

We're not talking about making it look great. This round is about communication.

TEAM GREYSCALE

And sometimes communication means education. If we genuinely believe broadband seismic is better understood in greyscale, why wouldn't we explain that?

ROUND 3 – What Best Serves the Interpreter?

TEAM COLOUR

The best display is the one the interpreter actually uses. Simple.

Most interpreters are looking at the subtle amplitude differences. And I’ve already told you colour works best for highlighting subtleties. Were you listening?

TEAM GREYSCALE

Yes, and you’re stuck in the past.

Broadband changed the way us processors looked at seismic. We adapted.

But maybe we've spent the last fifteen years giving interpreters better seismic...

without ever explaining why they should be looking at it differently.

TEAM COLOUR

Or maybe we've spent fifteen years telling interpreters they're wrong instead of listening to why they prefer colour.

And let's not forget, the real problem isn't colour, it's bad colour maps.

Nobody here is defending those old rainbow defaults. Modern scientific colour scales are a completely different conversation.

TEAM GREYSCALE

Maybe. But when you're interpreting a seismic stack. you're trying to understand the geology. Broadband in greyscale shows more of the seismic signal, so why would we choose to see less?

NOW, WATCH THIS DRIVE!