falsecolor scale adjustments

radiance-general
1

Hello all!

I'm attempting to customize the falsecolor scale to match the below scale (generated in photosphere) but unable to decipher the options required. Any insights on the -s and -log multipliers necessary? Is there a way to manually set the low end of the scale?

Thanks for your help! So very appreciated!
Kristen

[cid:[email protected]]

···

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2

Hi Kristen,

If I understand your question, you essentially want to have 6 log divisions with a maximum of 10000 cd/m^2. I think the following will work with falsecolor:

  falsecolor -log 6 -s 10000 -i image.hdr > image_fc.hdr

I guess you are not asking about the color scale itself, which should be the same as the default palette in falsecolor. (Running "falsecolor -palettes > pal.hdr" will show you the standard palattes you may choose from.)

Cheers,
-Greg

···

From: Kristen Garibaldi <[email protected]>
Date: August 10, 2017 12:41:57 PM PDT

Hello all!

I’m attempting to customize the falsecolor scale to match the below scale (generated in photosphere) but unable to decipher the options required. Any insights on the –s and –log multipliers necessary? Is there a way to manually set the low end of the scale?

Thanks for your help! So very appreciated!
Kristen

3

^ cool trick, Greg! #alwayssomethingnew #neverends #Radianceisdeep

···

On 8/10/17, 1:50 PM, "Greg Ward" <[email protected]> wrote:

(Running "falsecolor -palettes > pal.hdr" will show you the standard
palattes you may choose from.)

4

With the official Radiance version of falsecolor (coded in Perl), there is no way of adjusting the lower end of the scale.

Cheer
Axel

···

On 10/08/17 20:50, Greg Ward wrote:

Hi Kristen,

If I understand your question, you essentially want to have 6 log divisions with a maximum of 10000 cd/m^2. I think the following will work with falsecolor:

falsecolor -log 6 -s 10000 -i image.hdr > image_fc.hdr

I guess you are not asking about the color scale itself, which should be the same as the default palette in falsecolor. (Running "falsecolor -palettes > pal.hdr" will show you the standard palattes you may choose from.)

Cheers,
-Greg

*From: *Kristen Garibaldi <[email protected] <mailto:[email protected]>>

*Date: *August 10, 2017 12:41:57 PM PDT

*

Hello all!

I�m attempting to customize the falsecolor scale to match the below scale (generated in photosphere) but unable to decipher the options required. Any insights on the �s and �log multipliers necessary? Is there a way to manually set the low end of the scale?

Thanks for your help! So very appreciated!

Kristen

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5

Full credit to Axel Jacobs on this one -- he thought of this option, came up with the extra palettes, and re-implemented a better version of falsecolor.csh in Perl.

-Greg

···

From: "Guglielmetti, Robert" <[email protected]>
Date: August 10, 2017 12:54:42 PM PDT

On 8/10/17, 1:50 PM, "Greg Ward" <[email protected]> wrote:

(Running "falsecolor -palettes > pal.hdr" will show you the standard
palattes you may choose from.)

^ cool trick, Greg! #alwayssomethingnew #neverends #Radianceisdeep

6

While it's true that the minimum is always zero if you are using the default linear scale, setting a log scale allows you to (indirectly) specify the minimum as the scale setting divided by 10^N specified using the "-log N" option. (And "N" can be any positive value.)

I checked, and the setting I recommended works for your example.

Cheers,
-Greg

···

From: Axel Jacobs <[email protected]>
Date: August 10, 2017 1:01:01 PM PDT

With the official Radiance version of falsecolor (coded in Perl), there is no way of adjusting the lower end of the scale.

Cheer
Axel

On 10/08/17 20:50, Greg Ward wrote:

Hi Kristen,
If I understand your question, you essentially want to have 6 log divisions with a maximum of 10000 cd/m^2. I think the following will work with falsecolor:
falsecolor -log 6 -s 10000 -i image.hdr > image_fc.hdr
I guess you are not asking about the color scale itself, which should be the same as the default palette in falsecolor. (Running "falsecolor -palettes > pal.hdr" will show you the standard palattes you may choose from.)
Cheers,
-Greg

*From: *Kristen Garibaldi <[email protected] <mailto:[email protected]>>

*Date: *August 10, 2017 12:41:57 PM PDT

*
*

Hello all!

I’m attempting to customize the falsecolor scale to match the below scale (generated in photosphere) but unable to decipher the options required. Any insights on the –s and –log multipliers necessary? Is there a way to manually set the low end of the scale?

Thanks for your help! So very appreciated!

Kristen

7

Much appreciated all! Thanks!!!

Kristen

···

-----Original Message-----
From: Greg Ward [mailto:[email protected]]
Sent: Thursday, August 10, 2017 4:14 PM
To: Radiance general discussion
Subject: Re: [Radiance-general] falsecolor scale adjustments

While it's true that the minimum is always zero if you are using the default linear scale, setting a log scale allows you to (indirectly) specify the minimum as the scale setting divided by 10^N specified using the "-log N" option. (And "N" can be any positive value.)

I checked, and the setting I recommended works for your example.

Cheers,
-Greg

From: Axel Jacobs <[email protected]>
Date: August 10, 2017 1:01:01 PM PDT

With the official Radiance version of falsecolor (coded in Perl), there is no way of adjusting the lower end of the scale.

Cheer
Axel

On 10/08/17 20:50, Greg Ward wrote:

Hi Kristen,
If I understand your question, you essentially want to have 6 log divisions with a maximum of 10000 cd/m^2. I think the following will work with falsecolor:
falsecolor -log 6 -s 10000 -i image.hdr > image_fc.hdr I guess you
are not asking about the color scale itself, which should be the same
as the default palette in falsecolor. (Running "falsecolor -palettes
> pal.hdr" will show you the standard palattes you may choose from.)
Cheers, -Greg

*From: *Kristen Garibaldi <[email protected]
<mailto:[email protected]>>

*Date: *August 10, 2017 12:41:57 PM PDT

*
*

Hello all!

I'm attempting to customize the falsecolor scale to match the below scale (generated in photosphere) but unable to decipher the options required. Any insights on the -s and -log multipliers necessary? Is there a way to manually set the low end of the scale?

Thanks for your help! So very appreciated!

Kristen

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