# Average value of a Radiance image

Hi All,

Can anybody help me with a simple problem?
How do you evaluate the average value of a radiance (*.pic or *.hdr)
image?
Many thanks,

giovanni

Hi,

I suppose there is some command prompt command to do that easy and fast
(Greg?).

RadDisplay works on Windows and Linux.
When you open pic image in the program, create False Color image and then
press "Stats" button. In the dialog you 'll have various image statistics
and average luminance too.

Hope this helps,
Marija

···

On Tue, Jun 16, 2009 at 4:33 PM, Giovanni Betti < [email protected]> wrote:

Hi All,

Can anybody help me with a simple problem?
How do you evaluate the average value of a radiance (*.pic or *.hdr)
image?
Many thanks,

giovanni

Hi Giovanni,

There are a number of ways to do it, but I prefer using pvalue. For a color (RGB) average, you can use:

pvalue -h -H -df test.hdr | total -if3 -m

For grayscale average:

pvalue -b -h -H -df test.hdr | total -if1 -m

For original units (watts/sr/m^2) add a -o to either of the pvalue commands above.

-Greg

···

From: "Giovanni Betti" <[email protected]>
Date: June 16, 2009 7:33:25 AM PDT

Hi All,

Can anybody help me with a simple problem?
How do you evaluate the average value of a radiance (*.pic or *.hdr)
image?
Many thanks,

giovanni

Thanks both to Greg and Marija

···

-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Greg
Ward
Sent: 16 June 2009 16:07

Hi Giovanni,

There are a number of ways to do it, but I prefer using pvalue. For
a color (RGB) average, you can use:

pvalue -h -H -df test.hdr | total -if3 -m

For grayscale average:

pvalue -b -h -H -df test.hdr | total -if1 -m

For original units (watts/sr/m^2) add a -o to either of the pvalue
commands above.

-Greg

From: "Giovanni Betti" <[email protected]>
Date: June 16, 2009 7:33:25 AM PDT

Hi All,

Can anybody help me with a simple problem?
How do you evaluate the average value of a radiance (*.pic or *.hdr)
image?
Many thanks,

giovanni

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