Photo-Reactor Recipes

Upcoming mother of all image editors

Re: Photo-Reactor Recipes

Postby JEL » Fri Apr 11, 2014 3:51 am

RGB/CMY separator

This flow has 2 controls and is used to modify the weight of the 6 color-channels (RGBCMY)

The first control (top slider) is a merge-control. It sets how much the 6 color-channels are split into their 3 main components or merged into all 6.
It goes from zero to 100. Zero is fully split (into either RGB only or CMY only). 100 is fully merged (into RGBCMY)
When set to 100 the bottom-slider has no effect. When set to 0 the bottom-slider is fully effective.

RGBCMY (when top-slider is set to 100) is a normal image, but with a slight difference from normal colors. It's desaturating the CMY in their lower luma-values.

The second control (bottom slider) is a selection-control. It sets how much each set of 3 color-channels are used.
It goes from zero to 100. Zero is CMY only. 100 is RGB only.

There's an important difference between RGB and CMY;

When RGB only is selected (top-slider at zero and bottom-slider at 100) the CMY channels are fully desaturated but luma is still passed through (so they become monochrome)

When CMY only is selected (top-slider at zero and bottom-slider at zero) the RGB channels are fully turned OFF as in luma is NOT passed through (so they become fully black)


What it will do to the image:

Top 100, bottom 100: almost normal looking image, but with slightly muted complementaries. This will give a 'cleaner' or more defined looking image. Skin-tones will appear slightly more pink. Trees will appear slightly cleaner green.

Top 0, bottom 100: desaturated look, but with popping reds, greens and blues. Very similar to the old Technicolor 2-strip look actually. Skin-tones become very pink (a pleasing pink), brown hair becomes red. Trees become very even green. Blue skies become faded. Cyans, magentas and yellows are removed.

Top 0, bottom 0: desaturated look, but with popping cyans, magentas and yellows. Skin-tones become more 'sun-tanned', brown hair becomes earth-tone brown. Trees become yellowish green. Blue skies are amplified. Reds, greens and blues appears muted.

The white-balance of your input-image has a big effect on how the image looks in the various modes.


There's no specific purpose as such for this flow, but it can really make portraits pop. Perhaps flowers to (I haven't tried that myself, but perhaps Rachel will give that a go :) ). It's open if you need to modify anything in it or suit it into one of your own flows.

Enjoy! :)
Attachments
RGBCMYseparator_snapshot.jpg
RGBCMYseparator_snapshot.jpg (37.29 KiB) Viewed 14338 times
DAP (AOPs): http://jelstudio.dk/DAP/
PhotoReactor (flows, effects and scripts): http://jelstudio.dk/PhotoReactor/
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Re: Photo-Reactor Recipes

Postby Rachel » Sun Apr 13, 2014 4:38 pm

Jel, i will have some fun messing with your latest offering! I imagine I could have used it on this image to make the yellows green again.

This flow is made up of the gifts of others. If it works for you, thank all the contributors to this board!
Attachments
nice gift wc.jpg
nice gift wc.jpg (265.01 KiB) Viewed 14297 times
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Re: Photo-Reactor Recipes

Postby JEL » Sat Apr 19, 2014 12:23 pm

Rachel wrote:make the yellows green again.


I have battled that issue to. I've come up with 3 variations that are specifically aiming at reducing yellow color-cast in foliage (lawns, tree-leaves and such)

They all have strengths (less yellow where you don't want yellow) and weaknesses (less yellow where you do want yellow) ( :lol: ), but here they are:
Attachments
DeepGreen,KillYellow_snapshot.jpg
DeepGreen,KillYellow_snapshot.jpg (99.49 KiB) Viewed 14236 times
AddBlueToGreen,MinimizeYellowCastOnFoliage_snapshot.jpg
AddBlueToGreen,MinimizeYellowCastOnFoliage_snapshot.jpg (94.3 KiB) Viewed 14236 times
DAP (AOPs): http://jelstudio.dk/DAP/
PhotoReactor (flows, effects and scripts): http://jelstudio.dk/PhotoReactor/
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Re: Photo-Reactor Recipes

Postby Rachel » Sat Apr 19, 2014 6:26 pm

Fabulous! Thank you, Jel. I will download and give them a try. You are quite the wizard with PR.
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Re: Photo-Reactor Recipes

Postby Rachel » Sat Apr 19, 2014 6:46 pm

Ran the image with the new Jel color fixes, I think they will be super handy in the future. I played with the RGB/CMY separator but I am ignorant about the how and why of it all even with your great explanation. I imagine it will be useful at some future date for a specific image. If you see an image of mine that would benefit from its use let me know as I learn best from practice. :oops:
Attachments
with Jel's yellow to green.jpg
with Jel's yellow to green.jpg (248.73 KiB) Viewed 14224 times
Jel's add blue.jpg
Jel's add blue.jpg (243.32 KiB) Viewed 14224 times
DSCN1677web.jpg
DSCN1677web.jpg (257.08 KiB) Viewed 14224 times
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Re: Photo-Reactor Recipes

Postby Oscar » Wed May 21, 2014 7:27 pm

Experiment with creating poster in primary colors

DSC02714_Final.jpg
DSC02714_Final.jpg (177.29 KiB) Viewed 12475 times


poster.jpg
poster.jpg (233.59 KiB) Viewed 12475 times
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Re: Photo-Reactor Recipes

Postby JEL » Thu May 22, 2014 2:42 pm

Oscar wrote:Experiment with creating poster in primary colors


This is very sweet. Very Andy Warhol like :)
Works well on portraits also.
DAP (AOPs): http://jelstudio.dk/DAP/
PhotoReactor (flows, effects and scripts): http://jelstudio.dk/PhotoReactor/
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Converting film-negatives

Postby JEL » Tue Dec 02, 2014 2:47 am

Converting film-negatives to usable images is not as trivial as one might think.

I have spent some time constructing a flow that can do it correctly.

If this is a topic that has your interest, you may have seen how there is an abundant amount of articles on the internet on how to do colorfilm-conversion. That's good, until you discover that there seems to be as many different methods (yielding different end-results) as there are articles.

Some people will, to avoid drowning in articles, opt for a plugin (there is at least one very popular one, as far as I could find. I haven't tested it, but it gets good reviews. It's payware)

Until now :)
Because now you can use PhotoReactor :)

Unfortunately the champagne stays in the wine-cellar for just a bit longer. There is one major drawback to the PhotoReactor method I have come up with; bit depth.

Say you have scanned your film-negative in linear mode and import it into 8bit-PhotoReactor. In that case you will have between 5 and 7 bits available to work with*. Obviously this will not give as clean an image as if you could import it into a 16bit (or more) PhotoReactor.

*
blue ~5bit
green ~6bit
red ~between 6 and 7bit
*

However, the results can still be useful, but the bit-limitations will show (more on some negatives than on others, which is related to the color of the mask)

There's one more issue you might want to pay attention to, at least if you want extreme precision, and that is the film-response curve. In this flow there is no correction for individual film-response curves (for normal use this is not a problem, since these curves are very similar to each other, but for some connoisseurs it might be relevant)

Now, where this flow WILL (hopefully) excel, is in the fact that I have included TWO methods rather than just a single one :)

Method #1 will balance colors to give you a color-neutral image (a correct conversion)
This means blacks will be black, and whites will be white.

Method #2 will balance only the middle-grays, which has the neat side-effect of introducing a dual-tone effect that can be very aesthetically pleasing. The shadows will trend toward bluish tones, and the highlights towards golden/yellowish tones (you probably know this 'teal/orange'-like tone-scheme if you watch movies)
The strength of method2 depends on the film-negative's inherent color-balance. The more orange the mask is, the stronger the blue shadows will be. So this method can be hit or miss depending on the film-negative used.

Using the flow can be tricky, but here's a rundown:

First you must acquire a scanned image of your film-negative. This can be either linear or with the standard gamma2.2 applied.

The first node (levels node) in the flow applies a gamma of 2.2 to the source-image, so if your scan is NOT linear, then deactivate this first node (or correct the gamma setting such that you get an image with gamma 2.2)
(In the attached flow-snapshot the source-image is a linear scan of a Kodak film-negative)

After this first node, the flow splits into 2.

For a neutral image you follow the top flow-path.
For a tinted image you follow the bottom flow-path.

The procedure for both paths is similar. Here's the one for the neutral image:

Connect the top-scope (labeled 'neutral') to the layers-node with the multiply blend-mode selected (drag the output from the multiply node to the scope)

Now you will see that the red, green and blue histograms on the scope are unbalanced.

To counter this we will apply a counter-mask (a color that nulls out the orange mask of the film-negative)

We do this by adjusting the highlights cutoff in the red and green levels-nodes found on the left side (in each levels node the highlights cutoff is the control at the bottom on the right-hand panel)
The point is to adjust the highlights cutoff until the RGB bars on the scope align at each others top (basically you will move the red and green bar to align with the blue bar), which will place somewhere below the value of 128 on the scope (depending on the mask color of the film-negative)

When these 3 bars are aligned you move onwards in the flow-path to the levels-node at the top (just left of the output-node) where you adjust the shadow and highlights INPUT-levels to select the part of the histogram containing your image.

Finally you adjust the whitebalance (the kelvin-node) if needed (to do this connect the scope to the kelvin-node, as is shown in the flow-snapshot, so you can see if the RGB bars are aligned at their tops)

That's it :)

For method2 you do almost the same, except you do not balance the RGB bars at their tops but at their center (connect the linear-burn blend-mode node to the scope) AND you adjust only the green and blue channels (for film-negatives with orange colored masks)

Method2 is not setup to include a whitebalance-node, since the goal is to introduce a slight golden tint at the highlights, but if you wish you can probably do so.

Method2 will generally result in stronger, more saturated, colors, although they will obviously be non-neutral.

Choose whichever method you prefer with the film-negative you are converting.



A technical note; All films have different response-curves* that aren't completely linear, so the simple gamma adjustment performed in this flow will not be a perfect gamma-conversion.

*
Even if you know the film's published response-curve, this curve can change over time depending on how the film has been stored, how old it is, which batch it is from, etc.

However, to do a 'perfect' gamma-conversion you can setup 3 curve-nodes, one for each color-channel, instead of the first levels-node and do this specific gamma-conversion that way.

PhotoReactor makes it possible :)
Attachments
FilmNegativeConverter,2types,KodakGoldISO200,neutral.jpg
FilmNegativeConverter,2types,KodakGoldISO200,neutral.jpg (222.15 KiB) Viewed 10911 times
FilmNegativeConverter,2types,KodakGoldISO200_snapshot.jpg
FilmNegativeConverter,2types,KodakGoldISO200_snapshot.jpg (245.55 KiB) Viewed 10911 times
DAP (AOPs): http://jelstudio.dk/DAP/
PhotoReactor (flows, effects and scripts): http://jelstudio.dk/PhotoReactor/
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Re: Photo-Reactor Recipes

Postby minstrel » Wed Dec 03, 2014 5:28 am

Jel,
This is very interesting! Thanks for working on this and sharing your results.

I've multiple thousands of negatives that would take forever to scan using a dedicated film scanner. Maybe now I can easily make 'proof sheets' which will not only assist in cataloging but quickly highlight the best shots for re-scanning [higher resolution] with the dedicated scanner.

Could be a real time saver!...Thanks again!
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Re: Photo-Reactor Recipes

Postby JEL » Wed Dec 03, 2014 7:14 pm

minstrel wrote:I've multiple thousands of negatives that would take forever to scan using a dedicated film scanner. Maybe now I can easily make 'proof sheets' which will not only assist in cataloging but quickly highlight the best shots for re-scanning [higher resolution] with the dedicated scanner.


I believe it could be used for that, yes :)
DAP (AOPs): http://jelstudio.dk/DAP/
PhotoReactor (flows, effects and scripts): http://jelstudio.dk/PhotoReactor/
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