Separaing tones/hues

Moderator: jsachs

Marpel
Posts: 317
Joined: September 13th, 2009, 3:19 pm
What is the make/model of your primary camera?: Nikon D810
Location: Port Coquitlam, British Columbia

Separaing tones/hues

Postby Marpel » December 13th, 2017, 10:49 pm

Was out one recent foggy morning and captured an image of a traffic light (actually shot three images - one for each red/green/amber - then composited them in PWP, using "Lighten" blend mode - worked like a charm) with the lights emanating the rays into the fog.

Tried a number of attempts to exaggerate the light "beams", but found it quite difficult to do any transforms on the beams that did not also affect the surrounding background/fog. This included different composite blend modes like "Soft Light" etc. Also tried doing some masking to separate the beams from the background, but that didn't work so well because of the incredibly gradual fall-off from one to the other (and the pole cutting across the beams).

I'm wondering if anyone can suggest a PWP method/transform/blend mode that better suits my intent.

I have attached two images, one is the initial unworked, while the second is an image after some heavy processing (both Soft Light and Filter and other treatments, if I recall), just to show the type of effect I am trying for - however this image is way too dark in the background and extreme in the hues.

Marv
Attachments
lights-comp.jpg
lights-comp.jpg (92.27 KiB) Viewed 995 times
lights-comp-2.jpg
lights-comp-2.jpg (139.01 KiB) Viewed 995 times

jsachs
Posts: 1213
Joined: January 22nd, 2009, 11:03 pm

Re: Separaing tones/hues

Postby jsachs » December 14th, 2017, 12:35 am

Not at my computer, but have you tried increasing the saturation. Either with the Saturation or the Selective Color Correction transformations.
Jonathan Sachs
Digital Light & Color

Marpel
Posts: 317
Joined: September 13th, 2009, 3:19 pm
What is the make/model of your primary camera?: Nikon D810
Location: Port Coquitlam, British Columbia

Re: Separaing tones/hues

Postby Marpel » December 14th, 2017, 1:27 am

Jonathan,

Thanks for the reply.

I have tried both and found with Saturation, the entire image is affected and, although it does pump up the light beams, the background starts to take on a sickly orange colour. With Selective Colour, if selecting close to the light fixture, it works relatively well, however, the farther out the beam the selection is made, the more it affects the background as well. So to not effect the background, the selection has to be closer to the fixture. That results in part of the beam being intensified while the rest is ignored, making it look too unreal. I was hoping for the background to remain relatively neutral.

In short, I am trying to intensify the beams, without effecting the background too much which, with a normal hard edged object, a mask would work fine. However, because the transition from the coloured light beams to the background is so gradual and subtle, a mask is difficult at best (at least for me). I was hoping some Composite blending mode, that I am unaware of, might work.

Marv

jsachs
Posts: 1213
Joined: January 22nd, 2009, 11:03 pm

Re: Separaing tones/hues

Postby jsachs » December 14th, 2017, 8:24 am

I tried the following which may or may not be moving in the direction you want to go...

1) File New based on the original image and using the eyedropper to set the color of the new image to the background color.
2) Difference to subtract the background from the original, giving a more or less black background.
2.jpg
2.jpg (48.01 KiB) Viewed 983 times

3) Brightness curve to lighten the image, especially the darker parts
1.jpg
1.jpg (84.84 KiB) Viewed 983 times

4) Composite with the background image in Lighten mode, adjusting the overlay amount slider to restore some of the background
3.jpg
3.jpg (60.65 KiB) Viewed 983 times
Jonathan Sachs
Digital Light & Color

den
Posts: 688
Joined: April 25th, 2009, 6:33 pm
What is the make/model of your primary camera?: Canon EOS-350D/Fuji X100T
Location: Birch Bay near Blaine, WA USA

Re: Separaing tones/hues

Postby den » December 14th, 2017, 9:57 am

...
Try using a favored large radius sharpening method with a strong bias towards a dark halo... ...illustrated is USM but consider Bilateral and High Pass sharpening as well...
lights-comp_LargeRadiusUSM.jpg
lights-comp_LargeRadiusUSM.jpg (185.48 KiB) Viewed 970 times

A HighPass Sharpening illustration...
lights-comp_HiPassShrpn_1-1Clone.jpg
lights-comp_HiPassShrpn_1-1Clone.jpg (87.87 KiB) Viewed 970 times

...den...

jsachs
Posts: 1213
Joined: January 22nd, 2009, 11:03 pm

Re: Separaing tones/hues

Postby jsachs » December 14th, 2017, 11:33 am

Interesting idea, but sharpening the background makes its posterization more apparent.
Jonathan Sachs
Digital Light & Color

Marpel
Posts: 317
Joined: September 13th, 2009, 3:19 pm
What is the make/model of your primary camera?: Nikon D810
Location: Port Coquitlam, British Columbia

Re: Separaing tones/hues

Postby Marpel » December 14th, 2017, 10:02 pm

Jonathan and Den,

Thanks to both for the replies.

Jonathan, your approach actually looks like it works pretty well. I was looking for a more pronounced set of light beams without the background going crazy, which this seems to accomplish. I will have to play around with this a bit.

Den, as I have no experience with PWP's sharpening (I use Focus Magic for all my sharpening), I will have to study your method and, in particular, figure out what is meant by "....with a strong bias towards a dark halo...." (I presume you are referring to the Halo Limit slider).

Regards,

Marv

den
Posts: 688
Joined: April 25th, 2009, 6:33 pm
What is the make/model of your primary camera?: Canon EOS-350D/Fuji X100T
Location: Birch Bay near Blaine, WA USA

Re: Separaing tones/hues

Postby den » December 15th, 2017, 7:49 am

...
Yes, 'strong bias towards a dark halo' is the difference between the white and black Halo sliders of PWP's sharpening transforms... ... 'large radius sharpening' is also called Local Contrast Enhancement...

The Halo control can be manually duplicated with an image in PWP by:
1) create an "extreme" sharpened image version
2) Composite-Darken the original image to a preference Amount to simulate the Halo black slider
3) Composite-Lighten the resulting 2) image to a preference Amount to simulate the Halo white slider...
...using the "extreme" sharpened image version as the Overlay image in steps 2) and 3).

Another illustration using USM with a larger blur Radius and an increased Threshold to reduce the posterizing Jonathan points out that can occur...
LocalContrastEnhancement-USM_InputImage.jpg
LocalContrastEnhancement-USM_InputImage.jpg (138.14 KiB) Viewed 928 times
LCE-USM_TransformedImage.jpg
LCE-USM_TransformedImage.jpg (95.75 KiB) Viewed 928 times

...den...

P.S. Perhaps add a small amount of a RGB darkening contrast curve to add additional emphasis to beams:
DarkeningRGB_ContrastCurve.jpg
DarkeningRGB_ContrastCurve.jpg (179.17 KiB) Viewed 921 times

Marpel
Posts: 317
Joined: September 13th, 2009, 3:19 pm
What is the make/model of your primary camera?: Nikon D810
Location: Port Coquitlam, British Columbia

Re: Separaing tones/hues

Postby Marpel » December 15th, 2017, 10:53 pm

Thanks Den for the clarification.

I will be giving this a try.

Marv

den
Posts: 688
Joined: April 25th, 2009, 6:33 pm
What is the make/model of your primary camera?: Canon EOS-350D/Fuji X100T
Location: Birch Bay near Blaine, WA USA

Re: Separaing tones/hues

Postby den » December 16th, 2017, 4:29 pm

...
Marv...

Just for fun... ...from the original image's HSV-H channel, a cyan hue range was masked...
lights-comp.jpg_mask.jpg
lights-comp.jpg_mask.jpg (21.34 KiB) Viewed 875 times
...and using the Color Curves transform in the HSV color space the Hue and Saturation channel curves were adjusted to change the cyan light/beam to green...
lights-comp_cyan-green.jpg
lights-comp_cyan-green.jpg (98.71 KiB) Viewed 875 times

...den...


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