Talk:Tone mapping

Too many images?

There are an awful lot of images on this page, most of which add very little to the topic of tone mapping - they're just HDR photos with no information on the tone mapping algorithm used. The Grand Canyon image is the only one worth keeping from the Gallery IMHO, because it shows an example of direct (i.e. non gradient-based) tone mapping, which can be compared with the gradient-based tone mapping examples given in the sidebar pictures of the church and the beach, but I think the others should probably be deleted. I'll wait a couple of weeks before making the changes. Any comments? Chrisjohnson 13:07, 2 April 2007 (UTC)

Just a note, for Image:Victoria Inner Harbour HDR.png and Image:Victoria harbor yin-yan.jpg the original source images are available on the image page. I find one a good example of an unrealistic tone mapping result, and the other a realistic tone mapping result. Of course, these are my pictures so I may be biased. ^High_InBC^{(Need help? Ask me)} 13:40, 2 April 2007 (UTC)

Keeping examples of this sort does make sense if they're captioned as such. Keeping an example of an image with an obvious "halo" might also be good. I think having the original source images (or the one at EV 0.00) is valuable for this article, since it demonstrates what the tone mapping is actually doing. I'll see if I can get information and/or original images relating to some of the other photos. Chrisjohnson 17:30, 2 April 2007 (UTC)

I've incorporated a few of the (most exemplary, not necessarily 'best') images into a section on the visual effect of tone mapping, and have made a number of other changes. Probably most controversially, I've moved the previous title image down to the gallery of other images. It's a nice picture, but not especially high-dynamic range so it doesn't demonstrate tone mapping as well as some of the other images. Chrisjohnson 14:50, 22 May 2007 (UTC)

Needs a new intro

Intro doesn't explain anything to layman. It's all overwritten, overly complicated jargon. —Preceding unsigned comment added by 66.65.63.44 (talk) 04:25, 22 September 2008 (UTC)

Is it really better?

Unless I use masks to use the light exposure for the dark areas and the dark exposure for the light areas, does it really result in better pictures than if I just took a middle-exposure picture? There ought to be a comparison of middle-exposure versus two- and more- stepped tone mapped pictures to show the actual benefit of the whole process. - Keith D. Tyler ¶ 18:27, 23 August 2007 (UTC)

The masks are an integral part of the process, going back to dodging and burning in the days of photographic film. Taking the article's example of the church, a middle-exposure picture will have very dark shadows and a blindingly overexposed window, unless you took the shot with a camera that could capture a range of brightness values from almost complete darkness to bright sunshine (the Fuji S3/S5 Pro has an unusually wide dynamic range). But even if your camera could capture this range of values, no monitor would be able to display them, and so you would have to squash them down for viewing. As for "better" pictures, that is up to the photographer; the end results are often grotesquely and inappropriately technique-heavy, or just very dull and bland on account of the low contrast. But the technique can capture images that would otherwise have required a complicated lighting set-up, or in the case of outdoors images a magnesium flare on a huge crane. -Ashley Pomeroy (talk) 21:47, 3 January 2009 (UTC)

Some changes

I added a new section on the popularity of HDR tone mapping in digital photography and the reasons for it. Previously there wasn't much about this in the article, except some slightly garbled comments in the "visual effect" section. Possible some of this should be in the introduction? Right now it launches into math-speak, which isn't likely to help most visitors, who probably just want to know about the pretty pretty pictures. I also corrected an erroneous explanation of halos from the "visual effect" section, and added some comments on the aesthetics (which judging from the edit history lots of people care about, but no-one wants to comment on in the article!). Hope this is helpful - accidentally made my edits while not logged in so I thought I should comment. —Preceding unsigned comment added by Simonkinahan (talk • contribs) 22:34, 15 June 2009 (UTC)

Global vs. local tone mapping

This article needs a section explaining the difference between global and local tone mapping. —Darxus (talk) 17:47, 27 August 2009 (UTC)

Isn't that covered in the "Purpose and methods" section at the top? Simonkinahan (talk) 18:42, 27 August 2009 (UTC)

Yes, thank you. They could use graphical examples, preferably in contrast to an LDR original. I have a strong and possibly predictable preference for using contrast reduction as the example for global tone mapping. —Darxus (talk) 13:59, 28 August 2009 (UTC)

So... how is it actually done ?

I've read the article three times now and I still don't know how the individual images are actually combined into one. Software would be my guess. But this being an encyclopedia, I don't think I should have to guess.76.113.105.186 (talk) 21:39, 16 October 2010 (UTC) EDIT: And, by the way, I ask because I have photo editing software that utilizes layers. It just doesn't seem to have the ability to combine them in a way that would yield the results discussed here. So I'm particularly curious about that part of the process.75.109.227.5 (talk) 05:25, 29 October 2010 (UTC)

Ansel Adams

"Local adjustment of tonality in film processing [ie, when printing images] is primarily done via dodging and burning, and is particularly advocated by and associated with Ansel Adams, as described in his book The Print; see also his Zone System."

This is misleading. Dodging and burning were in use before Ansel Adams was born. Furthermore, the Zone System -- a form of tone mapping -- was supposed to reduce or eliminate the need for dodging and burning. It was commonly assumed that Adams did little dodging/burning. I was therefore surprised a few years ago when I learned that Adams commonly dodged and burned his prints, in addition to using the Zone System. WilliamSommerwerck (talk) 00:41, 4 January 2012 (UTC)

He also used developer-depletion techniques to prevent highly-exposed areas of film from blackening completely. Dilute developer with no agitation gives a partial effect : removing the film from the developer, soaking in pure water to allow developer absorbed in the gelatin to complete development of shadow areas. --195.137.93.171 (talk) 02:39, 27 February 2014 (UTC)

Removed section: "A local tone mapping algorithm without halos"

I removed the section called "A local tone mapping algorithm without halos", because:

• it gives undue weight to one particular piece of research,
• it is not in any way integrated with the rest of the article.

Maybe there is some salvageable material here, but whoever replaces it has to show that the work is notable. --Slashme (talk) 02:02, 20 September 2012 (UTC)

Hm, such an algorithm actually seems interesting, since most local tone mapping algorithms do give halos as a bi effect, which is not especially nice. Did the section cite any sources? Maybe it would be worth investigating what research have been presented about it and try to write a new, neutral section about it. —Kri (talk) 15:26, 29 May 2013 (UTC)

Difference between these two groups of tone mapping algorithms?

What is the difference between tone mapping algorithms based on contrast or gradient domain methods and tone mapping algorithms inspired by the anchoring theory of lightness perception, which are both described in the section Purpose and methods? According to the article and to the limited knowledge I have about tone mapping algorithms, the two groups practically seem to be the same. —Kri (talk) 15:33, 29 May 2013 (UTC)

"OpenCV code for Tone Mapping" doesn't fit in

https://en.wikipedia.org/wiki/Tone_mapping#OpenCV_code_for_Tone_Mapping It acts more as a tutorial rather than contributing to the article. I don't feel it belongs to the article, and it takes up a lot of space without being very helpful. — Preceding unsigned comment added by Gavekort (talk • contribs) 20:16, 2 November 2015 (UTC)