mind, though, that with 15 different operators (algorithms),
with between one and five slider controls and a few tickboxes,
you could be busy for quite some time.
The tone mapping default settings, as shown by the
thumbnails, tend not to include the more surreal and garish
type of images that are often thought of as HDR. Instead, to
varying degrees, most but not all of them are moderately
realistic in appearance. What’s more, playing with the
controls doesn’t produce really over-the-top results. If you
do crave that ‘traditional’ HDR look, we suggest that you
select the Mantiuk ’06 operator with the minimum Contrast
Factor and the maximum Saturation Factor. If that doesn’t
gofarenoughforyou,there’salwaystheoptionof
importingtheoutputofLuminanceHDRintoGIMPfora
bitofpost-processing.
WhileusingLuminanceHDRtocombineimagesyou
won’thaveburntyourbridgesonceyoudecideona tone
mapping.Thenon-tone-mappedHDRimagecanbesaved
asanHDRfileformat,ofwhichLuminanceHDRsupports
several.ThismeansthatyoucanopenthisHDRimagein
LuminanceHDRlateronandtryoutalternativetone
mappings.It alsomeans,ofcourse,thatyoucanshareyour
HDRimageswithothers,orcarryoutthetonemappingusing
differentsoftware.
OurreferencetoHDRfileformatsbringsustothesubjectof
RAWfiles.Asyoumightbeaware,somecamerassaveimages
ina formatknownasRAW,inadditiontomorefamiliarones
like JPEG. As the
name suggests, this
is the raw image
directly from the
camera’s sensor,
with no in-camera
processing carried
out. Different
manufacturers
have different
specifications for
their RAW formats,
buttypicallythey
store 12 or 14 bits
perpixelperprimary
colour,comparedto
8 bitsfora JPEGfile.
Thatmight
notsounda huge
difference,buteachadditionalbitdoublesthenumberof
tonalvaluesthatcanberepresented.Inotherwords,a RAW
filehasa muchlargerdynamicrangethana JPEGfileand,in
thatrespect,it’salmostanHDRformat.Thereasonfor
mentioningthisisthatLuminanceHDRcanimportRAWfiles,
andevenif youonlyimporta singleone,youcangoonto
tone-mapit,producinga similarresulttothatachievablewith
a fewJPEGfiles.QQIf tone mapping is pushed to the extreme, the
end result might not quite be realistic, but the
end result can be quite eye-catching.None of the exposures of this cave entrance
come close to representing the full dynamic
range of the scene, but combining them in
Luminance gives an effective result.Explore
HDR photography in GIMP
April 2020 | |^37