Single-Image HDR — Ask Tim Grey
[Source](http://asktimgrey.com/2017/06/05/single-image-hdr/ “Permalink to Single-Image HDR — Ask Tim Grey
Today’s Question: I’ve got a single image that has a pretty broad range of tonal values. Is there a way to create an HDR image from a single photo? I tried creating additional versions of the original (-2, -1, +1, +2 stops) and then combining them, but that didn’t work. Do you have any suggestions of what would work?
Tim’s Quick Answer: Put simply, you can’t create a true high dynamic range (HDR) image from a single exposure. You can, however, use the tone-mapping feature of most HDR processing software to apply adjustments to that single image.
More Detail: An HDR image involves combining multiple exposures into a single file, blending all of the information from the multiple images into a single processed image with a higher range of tonal values. This is the reason that an initial HDR image assembled from multiple 16-bit per channel captures will generally be a 32-bit per channel HDR image.
That 32-bit per channel image then needs to be tone-mapped to a “normal” tonal range represented by a 16-bit per channel image. This tone-mapping step can be applied to any image, even if it is not a true HDR image.
Some software tools for processing HDR images allow you to use multiple images processed from a single capture, using different exposure adjustments for each copy of the image. This would require that the RAW captures be processed and saved in another image format such as TIFF, however. If you simply made multiple copies of the same RAW capture with different adjustments saved in metadata, the HDR software would not be “fooled”, since the underlying RAW captures would all contain the same capture data.
So, there is no real reason to process the same RAW capture with multiple exposure adjustment variations. Instead you can simply open the original RAW capture in the HDR software, using the tone-mapping features to create the interpretation you prefer. Put simply, applying adjustments to create multiple interpretations of a single capture does provide any additional data compared to the single original RAW capture. To truly leverage the benefits of HDR imaging, you need to capture multiple bracketed exposures in the camera to begin with.
Learn Datalog Today!
Learn Datalog Today is an interactive tutorial designed to teach you the Datomic dialect of Datalog. Datalog is a declarative database query language with roots in logic programming. Datalog has similar expressive power as SQL.
Datomic is a new database with an interesting and novel architecture, giving its users a unique set of features. You can read more about Datomic at http://datomic.com and the architecture is described in some detail in this InfoQ article.
Table of Contents
This tutorial was written on rainy days for the Lisp In Summer Projects 2013. If you find bugs, or have suggestions on how to improve the tutorial, please visit the project on github.
Many thanks to Robert Stuttaford for his careful proof reading/editing. I’d also like to thank everyone who has contributed by fixing bugs and spelling mistakes.
Brando Skyhorse, Snap #807 - Born Identity - Snap Judgment
What’s in a name?
Special thanks to Brando Skyhorse. Check out Brando’s memoir, “Take this Man”, and his award winning novel, “The Madonnas of Echo Park.”
To learn more about Brando’s work, go towww.brandoskyhorse.com .
A very big thanks to Curt Wells and Bennington College.
Producer: Liz Mak
Original Score and Sound Design: Leon Morimoto
Stacey L. Kirby
Stacey’s Vimeo videos
Running on Cargo 
(25,920 views) Filed under [Stacey L. Kirby][4], [performance art][5], [book art][6], [installation art][7]
[Artist Residency and Performance][9]
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[SECCA, Winston-Salem, NC][11]
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[ArtPrize 8][13]
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[The Bureau of Personal Belonging][15]
[][16]
[I AM][17]
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[The Power of the Ballot][19]
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[ARTIST VIDEOS][21]
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[VALIDnation][23]
[][24]
[VALIDnation Cards][25]
[][26]
[I AM VALID Stickers][27]
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[The Declaration Project: 2013][29]
[3]: [4]: http://cargocollective.com/staceykirby/filter/Stacey-L.-Kirby [5]: http://cargocollective.com/staceykirby/filter/performance-art [6]: http://cargocollective.com/staceykirby/filter/book-art [7]: http://cargocollective.com/staceykirby/filter/installation-art [8]: 
[9]: http://cargocollective.com/staceykirby/Artist-Residency-and-Performance [10]: 
[11]: http://cargocollective.com/staceykirby/SECCA-Winston-Salem-NC [12]: 
[13]: http://cargocollective.com/staceykirby/ArtPrize-8 [14]: 
[15]: http://cargocollective.com/staceykirby/The-Bureau-of-Personal-Belonging [16]: 
[17]: http://cargocollective.com/staceykirby/I-AM [18]: 
[19]: http://cargocollective.com/staceykirby/The-Power-of-the-Ballot [20]: 
[21]: http://cargocollective.com/staceykirby/ARTIST-VIDEOS [22]: 
[23]: http://cargocollective.com/staceykirby/VALIDnation [24]: 
[25]: http://cargocollective.com/staceykirby/VALIDnation-Cards [26]: 
[27]: http://cargocollective.com/staceykirby/I-AM-VALID-Stickers [28]: 
[29]: http://cargocollective.com/staceykirby/The-Declaration-Project-2013
The Wonderful Hippie Era Has Gone
Looking Back at Everyday Life of Young People in the Late 1960s and 1970s
We’ve had such a wonderful life - the Hippie era. It was an era of new ideas such as new religious movements, spiritual awakening and freedom from conformity.
Hippies began to rebel against established traditions such as their parents’ religion and cultural expectations. This was a time of freedom, peace and love beyond comprehension.
A beautiful photo collection from spysgrandson will bring back to you a nostalgic look at the wonderful life that has gone.
