Luminous Landscape Forum
Raw & Post Processing, Printing => Digital Image Processing => Topic started by: Guillermo Luijk on May 10, 2007, 07:59:53 pm
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HISTOGRAMMAR TUTORIAL (http://www.guillermoluijk.com/tutorial/histogrammar/index_en.htm)
DOWNLOAD HISTOGRAMMAR (http://www.guillermoluijk.com/software/histogrammar/index.htm)
Histograms we usually see are compressed into an 8-bit range (0-255). However real histograms have much more detail since 16-bit allow to represent as many as 65536 different levels. RAW files are usually 12-bit files (some others like Leica M8 DNG are 8-bit) and this has important implications when developing our RAWs and converting to a wider 16-bits space.
To study histograms in detail I have developed a simple but powerful program that can read 16-bit images and provide a 15-bit (the reason for it not to be 16 is that Photoshop loses the 16th bit on all 16-bit images) detailed histogram.
You can check some visual (text in Spanish) histogram results here, making a comparision of Canon 5D vs Leica M8 vs DMR histograms:
http://www.ojodigital.com/foro/showthread....=100967&page=43 (http://www.ojodigital.com/foro/showthread.php?t=100967&page=43)
(http://img527.imageshack.us/img527/9414/hgramacm7.jpg)
Regards
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It would be helpful to have three display options for the x axis
1 gamma
2 f stops
3 zones
Marc
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It would be helpful to have three display options for the x axis
1 gamma
2 f stops
3 zones
Marc
[a href=\"index.php?act=findpost&pid=117299\"][{POST_SNAPBACK}][/a]
yeah, it's a good idea to ser a f-stop mode, so X-axis scale is logaritmic. I will implement that.
what do you mean with 3 zones?
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yeah, it's a good idea to ser a f-stop mode, so X-axis scale is logaritmic. I will implement that.
what do you mean with 3 zones?
[a href=\"index.php?act=findpost&pid=120584\"][{POST_SNAPBACK}][/a]
I should have written it more clearly
1) gamma
2) f stops
3) zones (I through IX)
Marc
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Hi all, I am sorry to make a revival of this post of mine, but I think it could be of interest to some of you analysing images in detail.
Some time ago I added a logarithmic mode to the program so as a 'Zone System' plot (both making sense only on linearly developed images, for instance with DCRAW), and now I have completely translated into English the tutorial so anyone interested can read it here HISTOGRAMMAR TUTORIAL (http://www.guillermoluijk.com/tutorial/histogrammar/index_en.htm)
To download it just press "DESCARGAR HISTOGRAMMAR V1.1" here: DOWNLOAD HISTOGRAMMAR (http://www.guillermoluijk.com/software/histogrammar/index.htm)
Regards
(http://www.guillermoluijk.com/software/histogrammar/hgrama.jpg)
(http://www.guillermoluijk.com/tutorial/histogrammar/resultgamma.jpg)
(http://www.guillermoluijk.com/tutorial/histogrammar/histolinlog.gif)
(http://www.guillermoluijk.com/tutorial/histogrammar/zonasluma.gif)
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I find that photo of the young lady passing by in the street quite intriguing.
Why is she looking so worried? The male in me wants to rush over and console her.
Has her grandmother just died? Does she now realise that she just can't afford that expensive pair of shoes she's just bought? Has she just been 'told off' by her supervisor at work? Has her boyfriend just left her? Has she just returned from a visit to the doctor who has informed her she is pregnant?
The speculation could be endless .
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I find that photo of the young lady passing by in the street quite intriguing.
Why is she looking so worried? The male in me wants to rush over and console her.
Has her grandmother just died? Does she now realise that she just can't afford that expensive pair of shoes she's just bought? Has she just been 'told off' by her supervisor at work? Has her boyfriend just left her? Has she just returned from a visit to the doctor who has informed her she is pregnant?
The speculation could be endless .
[{POST_SNAPBACK}][/a] (http://index.php?act=findpost&pid=137382\")
hahaha Ray. Just dramatic pose, she is an actress and they were shooting a movie in Piccadilly Circus in London when I passed by: [a href=\"http://www.pbase.com/gluijk/image/73730465]http://www.pbase.com/gluijk/image/73730465[/url]