Transformation Brightness Curve

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bulrichl
Posts: 7
Joined: April 30th, 2009, 1:41 pm

Transformation Brightness Curve

Post by bulrichl »

Hello,

I posted this a while ago but did not get a respond from the developers, therefore again:
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I encountered a problem with the transformation Gray/Brightness Curve... (PWPro 5.0.1.2, Windows XP Home, Service Pack 3):

1) Open a 48-bit color TIF picture,
2) call the transformation Gray/Brightness Curve,
3) choose Color Space: RGB,
4) close the transformation,
5) call the transformation Color/Extract Channel,
6) choose Channel: Red and click on OK,
7) call the transformation Gray/Brightness Curve.

The histogram of the monochrome picture (the red channel) is obviously incorrect. This bug has been in previous versions of PWPro (4.0 and if I remember correctly, 3.5 likewise).
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Kiril, Jonathan: could you have a look at it?

Bernd
Bob Walker
Posts: 78
Joined: April 25th, 2009, 9:08 am
What is the make/model of your primary camera?: Canon R5
Location: Los Alamos, New Mexico
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Re: Transformation Brightness Curve

Post by Bob Walker »

Bernd,

I can confirm what you see.

Some other observations:
(1) 48-bit TIF not required -- 24bit Jpeg shows same issue.
(6) Red channel not required, histogram shown is also wrong for extracted green channel (and probably blue channel).

The wrong histograms just show a spike or two at the 50% brightness level.

The new histogram tool for the grayscale color channel is OK.

BobW
jsachs
Posts: 4203
Joined: January 22nd, 2009, 11:03 pm

Re: Transformation Brightness Curve

Post by jsachs »

Thanks, I have fixed this for the next maintenance release.
Jonathan Sachs
Digital Light & Color
bulrichl
Posts: 7
Joined: April 30th, 2009, 1:41 pm

Re: Transformation Brightness Curve

Post by bulrichl »

Jonathan,

oh, I am the one to thank you! As I often work with color pictures and monochrome channels simultaneously, this strange behaviour happened frequently. So I will be very happy when it has been fixed.

Bernd
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