Monday, April 27, 2009

High Dynamic Range Imaging (HDRI).

Today;



+

+


=



- The image you see is known as an HDR. Some basic concept goes as such that a human eye can perceive around 14 exposure values (EV) whislt a normal CCD can see around 8 EVs (Terry Reinert : 1). This translates that 'we' do not usually see a real scene in an image. A real world scene may contain light ranges that exceed a 50,000:1 dynamic range whilst our displays and capture devices are limited to 300:1 dynamic range! ( Jon Meyer : The Problem )

The process of tone mapping through various algorithms has thus been developed in order to convert HDRs into 'displayeable' LDRs (low dynamic range) images. For capturing an HDR; the same scene may be shot with various exposure settings to get the best possible 'all-round' detail level of a scene and then all those exposures are merged to give a high dynamic range image. :)

The weird thing, again, is the software I used for the creation of this HDR known as Qstpfgui. Yes, I agree it has a weird name but that's not about that.. but about it being an open source project which beats the 5hit out of proprietary softwares.


Further reading :

http://en.wikipedia.org/wiki/High_dynamic_range_imaging

http://www.cybergrain.com/tech/hdr/

http://www.tkrphoto.com/2009/04/hdr-photography-faq/

http://www.digitalphotopro.com/technique/software-technique/xdr-part-iv.html