Modifying A 'Gaussian Blur' Tool Use Question

Rather than applying a gaussian blur uniformly over an entire picture,
it'd be really neat to be able to vary the radius and strength of the blur to
proportionally and inversely match to the square-root of the average
luminance of a sample field in question. IOW, I'm trying to reduce that shot
noise, especially for higher ISO pictures. Call it a tailor made color-
luminance noise filter.


Anybody have any ideas on how to accomplish this? How to make a variable
blur, depending upon the brightness of an area? I'd go even so far as to do
individual profiles for each of the color fields.

Thanks for any answers.


--
__
SneakyP
To email me, you know what to do.

Supernews, if you get a complaint from a Jamie Baillie, please see:
http://www.canadianisp.ca/jamie_baillie.html

On Fri, 11 Mar 2011 22:52:14 -0600, SneakyP
wrote:


Rather than applying a gaussian blur uniformly over an entire picture,
it'd be really neat to be able to vary the radius and strength of the blur to
proportionally and inversely match to the square-root of the average
luminance of a sample field in question. IOW, I'm trying to reduce that shot
noise, especially for higher ISO pictures. Call it a tailor made color-
luminance noise filter.


Anybody have any ideas on how to accomplish this? How to make a variable
blur, depending upon the brightness of an area? I'd go even so far as to do
individual profiles for each of the color fields.

Thanks for any answers.

I use PhotoLine with its built-in "Variable Blur" filter. Most often used
to create realistic DOF effects by using a depth-mask, but it can be used
even more simply for what you need it for.

You MORON.

I hope you enjoyed poking your own eyes out!

I just love people who wallow in their own self-induced ignorance.

LOL!

SneakyP wrote:
Rather than applying a gaussian blur uniformly over an entire picture,
it'd be really neat to be able to vary the radius and strength of the blur to
proportionally and inversely match to the square-root of the average
luminance of a sample field in question. IOW, I'm trying to reduce that shot
noise, especially for higher ISO pictures. Call it a tailor made color-
luminance noise filter.

Anybody have any ideas on how to accomplish this? How to make a variable
blur, depending upon the brightness of an area? I'd go even so far as to do
individual profiles for each of the color fields.

Thanks for any answers.

Interesting idea. It would probably work on some
images, but I'm in doubt about any "automatic" selection
or intesity methods for procesing images. I *always*
want to very precisely do that sort of thing manually.
(I guess that means I'm picky picky picky, eh?)

In particular the feathering on selection areas is
something that makes a lot of difference. Sometimes it
takes several different individual applications (of
blur, sharpening, contrast, whatever), using different
selections and with different feathering.

A simple example would be hand drawing a selection
around a person's head and shoulders, feathering it at
10 pixels, and doing USM or sharpen; then invert the
selection at do a blur at maybe a 5 pixel radius. Then
shrink the selection by 50 and set the feathering to
100, and set the blur to a 10 pixel radius. Then shrink
the selection by 150 and set feathering to 400 and do a
blur at a 20 pixel radius. It might also be useful to
change contrast and brightness at each selection too, or
perhaps only on the last one.

For portraits that process might be done fairly
aggressively, but to remove shot noise from the sky it
might be a little less so? It depends on what is
important. The skyline, where the horizon meets the sky
is sometimes significant, other times not at all. The
same is true of tonal variations of clouds in the sky.
The trick is to feather selections so that there is a
smooth transition and to avoid changing areas where
other detail is important.

--
Floyd L. Davidson http://www.apaflo.com/floyd_davidson
Ukpeagvik (Barrow, Alaska)

On 03/12/2011 05:52 AM, SneakyP wrote:
Rather than applying a gaussian blur uniformly over an entire picture,
it'd be really neat to be able to vary the radius and strength of the blur to
proportionally and inversely match to the square-root of the average
luminance of a sample field in question. IOW, I'm trying to reduce that shot
noise, especially for higher ISO pictures. Call it a tailor made color-
luminance noise filter.


Anybody have any ideas on how to accomplish this? How to make a variable
blur, depending upon the brightness of an area? I'd go even so far as to do
individual profiles for each of the color fields.

Thanks for any answers.

To do it manually, you would have several layers with increasing blur
levels, and you would use specific masks on them depending on luminance
(extract luminance channel, move to layer mask and threshold it).

--
Bertrand

On 03/12/2011 06:03 AM, LOL! wrote:


I use PhotoLine with its built-in "Variable Blur" filter. Most often used
to create realistic DOF effects by using a depth-mask,

Holy cow... you add DOF effects to your tack-sharp-everywhere photographs?

--
Bertrand

On Sat, 12 Mar 2011 13:31:13 +0100, Ofnuts
wrote:

On 03/12/2011 05:52 AM, SneakyP wrote:
Rather than applying a gaussian blur uniformly over an entire picture,
it'd be really neat to be able to vary the radius and strength of the blur to
proportionally and inversely match to the square-root of the average
luminance of a sample field in question. IOW, I'm trying to reduce that shot
noise, especially for higher ISO pictures. Call it a tailor made color-
luminance noise filter.


Anybody have any ideas on how to accomplish this? How to make a variable
blur, depending upon the brightness of an area? I'd go even so far as to do
individual profiles for each of the color fields.

Thanks for any answers.

To do it manually, you would have several layers with increasing blur
levels, and you would use specific masks on them depending on luminance
(extract luminance channel, move to layer mask and threshold it).

Like cameras, you've never used any photo editors either, eh? Thought so.

LOL!

On 03/12/2011 03:32 PM, LOL! wrote:
On Sat, 12 Mar 2011 13:31:13 +0100,
wrote:

On 03/12/2011 05:52 AM, SneakyP wrote:
Rather than applying a gaussian blur uniformly over an entire picture,
it'd be really neat to be able to vary the radius and strength of the blur to
proportionally and inversely match to the square-root of the average
luminance of a sample field in question. IOW, I'm trying to reduce that shot
noise, especially for higher ISO pictures. Call it a tailor made color-
luminance noise filter.


Anybody have any ideas on how to accomplish this? How to make a variable
blur, depending upon the brightness of an area? I'd go even so far as to do
individual profiles for each of the color fields.

Thanks for any answers.

To do it manually, you would have several layers with increasing blur
levels, and you would use specific masks on them depending on luminance
(extract luminance channel, move to layer mask and threshold it).

Like cameras, you've never used any photo editors either, eh? Thought so.

I'm obviouly not the only one:

http://groups.google.com/group/rec.photo.digital/browse_thread/thread/775f33716ee361fa/b300ff00783963bd?hl=en&lnk=gst&q=photoline+missing +pixels+group%3Arec.photo.*#b300ff00783963bd

Remember?

--
Bertrand

On Sat, 12 Mar 2011 23:58:21 +0100, Ofnuts
wrote:

On 03/12/2011 03:32 PM, LOL! wrote:
On Sat, 12 Mar 2011 13:31:13 +0100,
wrote:

On 03/12/2011 05:52 AM, SneakyP wrote:
Rather than applying a gaussian blur uniformly over an entire picture,
it'd be really neat to be able to vary the radius and strength of the blur to
proportionally and inversely match to the square-root of the average
luminance of a sample field in question. IOW, I'm trying to reduce that shot
noise, especially for higher ISO pictures. Call it a tailor made color-
luminance noise filter.


Anybody have any ideas on how to accomplish this? How to make a variable
blur, depending upon the brightness of an area? I'd go even so far as to do
individual profiles for each of the color fields.

Thanks for any answers.

To do it manually, you would have several layers with increasing blur
levels, and you would use specific masks on them depending on luminance
(extract luminance channel, move to layer mask and threshold it).

Like cameras, you've never used any photo editors either, eh? Thought so.

I'm obviouly not the only one:

http://groups.google.com/group/rec.photo.digital/browse_thread/thread/775f33716ee361fa/b300ff00783963bd?hl=en&lnk=gst&q=photoline+missing +pixels+group%3Arec.photo.*#b300ff00783963bd

Remember?

After reading it, it clearly proves you to be a know-nothing troll and were
dead wrong, again. Is that what you were hoping to show everyone again?

LOL!

(Floyd L. Davidson) wrote in :

Interesting idea. It would probably work on some
images, but I'm in doubt about any "automatic" selection
or intesity methods for procesing images. I *always*
want to very precisely do that sort of thing manually.
(I guess that means I'm picky picky picky, eh?)



Nothing wrong with manually correcting the picture. This does seem to be an
artists area. But, a very-mild noise reduction on a picture might minimize
any further work needed in certain situations. Masking such a process may be
the trick.


Thanks for the rest of the tips, though. Have to experiment with that.

--
__
SneakyP
To email me, you know what to do.

Supernews, if you get a complaint from a Jamie Baillie, please see:
http://www.canadianisp.ca/jamie_baillie.html

On 03/13/2011 12:09 AM, LOL! wrote:

Like cameras, you've never used any photo editors either, eh? Thought so.

I'm obviouly not the only one:

http://groups.google.com/group/rec.photo.digital/browse_thread/thread/775f33716ee361fa/b300ff00783963bd?hl=en&lnk=gst&q=photoline+missing +pixels+group%3Arec.photo.*#b300ff00783963bd

Remember?

After reading it, it clearly proves you to be a know-nothing troll and were
dead wrong, again. Is that what you were hoping to show everyone again?

Ah, so you can't read...

*rattle*
--
Bertrand