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Red, Purple and Pink: The Colors of Diffusion on Pinterest

Kevin Stecyk
 

For those that are interested, here's an abstract of an academic article titled "Red, Purple and Pink: The Colors of Diffusion on Pinterest." You can click on the link in the prior sentence to read the article.

Many lab studies have shown that colors can evoke powerful emotions and impact human behavior. Might these phenomena drive how we act online? A key research challenge for image-sharing communities is uncovering the mechanisms by which content spreads through the community. In this paper, we investigate whether there is link between color and diffusion. Drawing on a corpus of one million images crawled from Pinterest, we find that color significantly impacts the diffusion of images and adoption of content on image sharing communities such as Pinterest, even after partially controlling for network structure and activity. Specifically, Red, Purple and pink seem to promote diffusion, while Green, Blue, Black and Yellow suppress it. To our knowledge, our study is the first to investigate how colors relate to online user behavior. In addition to contributing to the research conversation surrounding diffusion, these findings suggest future work using sophisticated computer vision techniques. We conclude with a discussion on the theoretical, practical and design implications suggested by this work—e.g. design of engaging image filters.
From the article, I interpret diffusion to mean sharing.


moderated Re: Case Study: Veiled Bride

Dan Margulis
 



On May 25, 2020, at 11:00 AM, k_d@... wrote:

Excellent. Pscc2020 flyout for the .dng is greyed out to clear any crop, and click on return to original makes no changes. So I still assume the .dng is not cropped.

Check the supplied JPGs, which are the “official” size for the case study. The .dng crop, if it is still being honored, is grossly different, so there shouldn’t be any doubt.


moderated Re: Case Study: Veiled Bride

Doug Schafer
 

On Mon, May 25, 2020 at 03:29 AM, Dan Margulis wrote:
Camera Raw there is a crop icon in the tool bar. A flyout next to it allows clearing the crop.
Excellent. Pscc2020 flyout for the .dng is greyed out to clear any crop, and click on return to original makes no changes. So I still assume the .dng is not cropped.

Doug Schafer


moderated Re: Case Study: Veiled Bride

Dan Margulis
 



On May 24, 2020, at 5:44 PM, k_d@... wrote:


And if we did need to undo a crop or anything else, just how is that accomplished? I assume it is like removing a sidecar .xmp file; but how is that done on a .dng?

It depends on the raw converter. In my version of Camera Raw there is a crop icon in the tool bar. A flyout next to it allows clearing the crop.



moderated Re: Case Study: Veiled Bride

Dan Margulis
 



On May 24, 2020, at 9:23 PM, Harvey Nagai via groups.io <hnagai@...> wrote:

On Sun, May 24, 2020 at 01:23 PM, Dan Margulis wrote:
Also, DO NOT APPLY UNSHARP MASKING. These retouchers weren’t allowed to so the comparison would not be fair.
 
Does this apply only to "normal" (edge) sharpening, or also to hiraloam sharpening?

My interpretation is no use of the unsharp mask filter, or any technique whose sole purpose is to emulate it.


moderated Re: Case Study: Veiled Bride

Harvey Nagai
 

On Sun, May 24, 2020 at 01:23 PM, Dan Margulis wrote:
Also, DO NOT APPLY UNSHARP MASKING. These retouchers weren’t allowed to so the comparison would not be fair.
 
Does this apply only to "normal" (edge) sharpening, or also to hiraloam sharpening?


moderated Re: Case Study: Veiled Bride

Doug Schafer
 

Dan,
I downloaded the .zip as I prefer to use raw/dng to start.
.dng Image opened at correct image size 3504x2336, meta data says it is cropped to that and looks just like the other .jpg sizes and crop.
So apparently no crop correction needed?

And if we did need to undo a crop or anything else, just how is that accomplished? I assume it is like removing a sidecar .xmp file; but how is that done on a .dng?

Doug Schafer


Re: Carnival: what's next?

Doug Schafer
 

Daniele DiStanio has a website called Color Duels which offers once a week image correction challenge and video feedback for all the entries as well as education and tips. Excellent way of learning. He and Dan are friends.  go to ColorDuels.com to learn more. Home base is Italy.

Doug Schafer


moderated Case Study: Veiled Bride

Dan Margulis
 

By popular demand, more or less, we’ll try another one. Choosing a particular exercise is nuisance because no one image is interesting to everyone, nor does every image illustrate every possible technique. So I chose ten. to illustrate a variety: three portraits (one from an iPhone), three scenics, two night shots, one flower, and even a restoration of a faded color print. About half of these are pretty hard, IMHO.

Of course we’ll do them one at a time. If people continue to contribute, and I’ve got the availability, maybe we’ll get through all ten eventually, otherwise we’ll cut it short when appropriate.

Four of the exercises come from my own files but six, including this first one, come from the MIT study of 5,000 images, about which I’ve posted several times in my blog, beginning with

As you may remember, the images are supposed to represent those typical of professional work. Five intermediate retouchers were hired to attack them. Of course, I’m going to post their versions along with yours. This may help boost your spirits. Some of the people who entered the Carnival case study are not known to me but several are notably fine technicians. On a more difficult image than that one, some might get quite discouraged when comparing their efforts to those of these sharks. That won’t be a problem here, believe me; a couple of these hired guns did a particularly putrid job.

This first image is a wedding shot, a portrait of the bride. The challenge is that half the face is covered by her veil and the other half is not. You can take a look at the new photo album,

The retouchers were given raw (well, .dng actually) files, which our Photos section doesn’t support. One of the JPEGs in the album is a default open in Camera Raw, the other a flatter version of the type I prefer to start with. You’re welcome to work with either. If you’d like the .dng, you can download veiled_bride.zip (which also contains the two versions above) from our Files section,

If you do use the .dng, be sure to remove its internal crops, and to resize it as needed to match the supplied JPEGs.

Also, DO NOT APPLY UNSHARP MASKING. These retouchers weren’t allowed to so the comparison would not be fair.

Remember: the files should be sent to me personally. 
DO NOT POST THEM TO THE LIST!!!

The image attached here is low-res, not for reproduction!

Appended are the rules for this case study, and a thumbnail.

Dan

*In the study, no instructions were given as to what the client wanted. Here, let us assume that it is for placement in a wedding album.

*You can use whatever methods you like to improve the picture EXCEPT AN UNSHARP MASK filter or similar, because the original retouchers in the MIT study were not allowed to.

*Please keep clear records of what you did for discussion. List members find these very valuable.

*In the Photos section, Case Study: Veiled Bride, I have uploaded a version opened with Camera Raw defaults, and another where the settings were much flatter. You may use either, or fetch the .dng as below.

*groups.io does not allow .dng format in the Photos section. If you want the .dng, you must download a zipped file from the Files section. NOTE: the zipped file contains the two default images as well, you don't need to download them separately.

*The designated size of this exercise is 3504 x 2336 pixels. If you use the .dng image you MUST remove the existing crops, and open into the correct size. Do not crop, rotate, or alter the sizing.

*Your final file is to be sRGB with a proper tag. If you work in a different RGB you must Edit: Convert to Profile>sRGB before submitting the file.

*When finished, save in JPEG form, quality level 9. E-mail it to me, dmargulis@..., with a brief explanation of how you produced it includingwhat file you used for your original. DO NOT POST IMAGES TO THE LIST!

*Entries close Monday morning, 1 June, at 06:00 Eastern/11:00Z, 12:00 ora italiana.

*Rather than confirm every entrant I've received, I will periodically post the initials of everyone whose file I have.

*As soon as convenient after the deadline, I'll post all the entrants in a random order. Names will not be revealed except for those entrants that I or somebody else has declared to be particularly good, which will come later.

*A discussion will follow within a few days after posting the final files. 





Re: Carnival: what's next?

Roberto Tartaglione
 

I’m really interested in more case studies Dan; in real world It is not easy to face with others about technical or aesthetical aspects of photography or pre-press.
Dealing with list members who share their Know How under your coordination, represents a step ahed for all of us.

Hope this is a common thinking.


Roberto Tartaglione
roberto@tartaglione.com


Re: Carnival: what's next?

Dan Margulis
 

OK, we’ll try another.

Dan

On May 23, 2020, at 6:38 PM, James Gray <James@...> wrote:

I am in favor of more case studies.  Even though I did not participate in the Carnival challenge, I always learn from what the participants do and the many comments, especially, yours, Dan.


Re: Carnival: what's next?

James Gray
 

I am in favor of more case studies.  Even though I did not participate in the Carnival challenge, I always learn from what the participants do and the many comments, especially, yours, Dan.

James Gray


On Sat, May 23, 2020 at 9:46 AM Dan Margulis via groups.io <dmargulis=aol.com@groups.io> wrote:

It’s true that this is a very atypical image. OTOH it represents a category that we are probably seeing more of: a job where technical limitations (in this case, a lack of gamut) make it impossible to achieve what we would like (in this case, matching an extremely intense red). People who don’t understand the process give the work to us to figure out what is and is not possible. And not just to execute, but to explain.

This brings up the question of whether to do more case studies. I’m still stuck at home and so are many of us so it could probably be done. Then again many of us are not necessarily in the mood for such diversions. I’ve got more than enough interesting images but what we would need is interested people, since it takes an effort to run these case studies. So I ask now whether the list would like to see more of them. I won’t be offended if the answer is no.




Re: Carnival: what's next?

Harvey Nagai
 

I found out about this group list only a few years ago, and in mining the
messages archive had discovered the Challenges and Case Studies of yore.
Those were highly instructive in a way that just isn't possible from
presentation formats (i.e. books, articles, videos). Seeing the creative
successes and also the not-so-successful results was interesting, reading
the commentaries was invaluable.

So I would very much welcome a return of case studies, if it wouldn't be
too much trouble.


Re: Carnival: what's next?

George Machen
 

Case studies would seem to be the very raison d'être of this group! We were limited by storage restrictions on Yahoo, but I can only find in our FAQ restrictions on individual photo sizes, not a total for a given group. (100 MB per photo in Basic groups, 500MB in Premium and Enterprise groups)

Dan's time and disposition are not infinitely elastic; I would think that he doesn't have to participate in every case study (although the more the better!), if that would mean more case studies. And I suppose we could always rein it in if it gets out of hand.

-- 
George Machen
 


Re: Carnival: what's next?

bill bane
 

I would love to see and try some additional whacks with additional case studies.

 

Bill Bane

 

From: colortheory@groups.io <colortheory@groups.io> On Behalf Of ROBIN MARK D'ROZARIO
Sent: Saturday, May 23, 2020 11:10 AM
To: colortheory@groups.io
Subject: Re: [colortheory] Carnival: what's next?

 

Dear Dan,
I enjoyed the Carnival exercise and vote Yes for further case studies.
Best regards,
Robin Mark D'ROZARIO


Re: Carnival: what's next?

Thomas Hurd,MD
 

I am interested in more case studies. I also enjoyed the Carnival case study very much.

Tom Hurd

On May 23, 2020, at 12:10 PM, ROBIN MARK D'ROZARIO <rdrozario@...> wrote:

Dear Dan,
I enjoyed the Carnival exercise and vote Yes for further case studies.
Best regards,
Robin Mark D'ROZARIO


Re: Carnival: what's next?

ROBIN MARK D'ROZARIO
 

Dear Dan,
I enjoyed the Carnival exercise and vote Yes for further case studies.
Best regards,
Robin Mark D'ROZARIO


Carnival: what's next?

Dan Margulis
 

Unless someone wants further discussion this will be my last post on the Carnival image. In past case studies we’ve tried to pick winners. Here, the top entrants are so close that trying to choose between them is like splitting hairs.

Also, in previous studies there have always been some completely fouled-up entries, useful because it highlights misconceptions. Here, the only obvious mistake was that some people concentrated so much on the reds that they ignored the need for strong yellows. Even so, there were no really bad entries.

I do think it was a worthwhile exercise. It highlighted some excellent techniques. It also may have instilled some confidence, because several people in their notes describing technique said things like “I’m sure this is going to seem terrible next to the others, because I know absolutely nothing about CMYK.” And of course they all did well.

It’s true that this is a very atypical image. OTOH it represents a category that we are probably seeing more of: a job where technical limitations (in this case, a lack of gamut) make it impossible to achieve what we would like (in this case, matching an extremely intense red). People who don’t understand the process give the work to us to figure out what is and is not possible. And not just to execute, but to explain.

This brings up the question of whether to do more case studies. I’m still stuck at home and so are many of us so it could probably be done. Then again many of us are not necessarily in the mood for such diversions. I’ve got more than enough interesting images but what we would need is interested people, since it takes an effort to run these case studies. So I ask now whether the list would like to see more of them. I won’t be offended if the answer is no.

Before signing off let me discuss one special Carnival case. The original artwork is silhouetted, no background at all. In #217 Harvey Nagal had the inspiration of adding a gradated black background. In his notes, he cited Chevreul, reasoning that the red robe would appear more brilliant against black than against white. And in this he was correct. There was nothing in the instructions to prevent this move, although in real life we’d need to run it by the client first.

In real life offset printing, large black areas like this can have unintended consequences, even if technically the file complies with the ink limit. So I would recommend not using this file in real life unless you are really confident about your press conditions.

Something lighter, however, might work. Harvey said he first had tried a pure Chevreul move of making the background the complementary of the robe, which in this case would be a cyan rather than a black. He reports: “I replaced the background with the inverse color of the costume, and found that the costume did indeed look as colorful in CMYK as it did in the original RGB image. The background looked like the worst puke spewing from a sewage pipe, but neutralizing the hue showed that the luminance contrast was sufficient to make the colors look brighter.”

I would point out that there are intermediate possibilities between dead black and bright cyan. Also, that it doesn’t have to be the exact complementary: anything cool might do. And white is the most brilliant background possible, so *anything* that darkens it may have a helpful effect—it doesn’t have to be a black.

You may wish to test this for yourself by downloading and blending #217 into your own version, at say 25% opacity. Or you might try a blend that partially excludes the green channel, making the background slightly purple rather than black. Or any of a hundred other permutations. The results are interesting.

Dan


Choosing the Best RGB Space as a Source for Channel Blending

Rick Gordon
 

It might be an interesting test to see if sRGB would normally be better for extracting channels for blending. My own sense is that, since channel blending is likely to be called for when there is missing detail in a current channel (i.e., either clipped or nearly clipped to either black or white), that the most suitable channel to blend with would be one that has sufficient latitude at both extremes, and that a wide-gamut space such as ProPhoto RGB would be the most serviceable.

This is a different argument than the argument that a wide-gamut space is always preferable as a composite RGB space. I generally concur with Dan's assessment that a smaller space may be a better tool for that if the gamut required is not excessive. However, since I opt to edit in 16-bit (though not necessarily use as final), I believe that the argument — that banding is more likely to occur when the values are compressed within a smaller range of gray values — may be mitigated by the 16-bit workflow. (But I dare not open that can of worms again.)

But I do think that some real-world testing of that hypothesis might be informative, in terms of the value of generally using a high-gamut space (e.g., ProPhoto RGB) as a source to derive unclipped individual channels.

Rick Gordon

--------------------
On May 20, 2020 at 5:57:25 PM [-0700], Dan Margulis Via Groups.io wrote in an email entitled "Re: [colortheory] The group's techniques, 2":
In more normal work it wouldn’t make a difference, and if it did sRGB would likely be a better choice than ProPhoto.
___________________________________________
RICK GORDON
EMERALD VALLEY GRAPHICS AND CONSULTING
___________________________________________
WWW: http://www.shelterpub.com


Re: Topaz Gigapixel AI anyone using it.

Beat C
 

I have once tried Topaz Gigapixel for blowing up a 10 Mb image to about 4 times it’s size (so 2 times as wide and 2 times as high).
I compared to PS enlargement algorithms. The Gigapixel result seemed better, until I discovered that it sharpens as well. The PS mode ‘Keep details’ does that as well, but less.
I eventually used the PS enlargement, as I had to do a lot of processing after the enlargement (complicated image from 3 images and lots of blends and processing), so I didn’t want to start off with sharpening in the beginning.
To really compare Gigapixel and PS enlargement, the sharpening should be the same. I have the idea, that starting with a good medium to big sized image (I have no experience with small images), the PS algorithm performs not much worse than the Gigapixel. And I think the Topaz products are rather expensive and not very user friendly.

Beat Cornaz

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