====== HDR (High Dynamic Range) ======

===== Tips =====

  * Standard way: 3 photos at -2,0,+2 EV. Very hard to realistically blend photos wider than 4 EV (automatic tools will either ignore extreme photos or produce unrealistic HDR photos).


===== Tools =====

==== Hugin/enfuse ====

Does not work correctly with Hugin, better use directly enfuse.

If image were taken with a tripod and are already aligned, directly used enfuse:
<code bash>
#!/bin/bash

n_input=$#
inputs=($*)

output=`echo ${inputs[0]} | sed -r "s@(.*_[0-9]+)[^/]*\\$@\1@"`-`echo ${inputs[$(($n_input-1))]} | sed -r "s@.*_[0-9]+([0-9]{2})[^/]*\\$@\1@"`.jpg

enfuse -o $output ${inputs[*]}

# fixme because hugin 2011.04 creates buggy jpg currently
convert $output $output
</code>

If you didn't use a tripod, or if the clouds are moving fast, align images before:
<code bash>
#!/bin/bash

n_input=$#
inputs=($*)

output=`echo ${inputs[0]} | sed -r "s@(.*_[0-9]+)[^/]*\\$@\1@"`-`echo ${inputs[$(($n_input-1))]} | sed -r "s@.*_[0-9]+([0-9]{2})[^/]*\\$@\1@"`.jpg
prefix=AHDR_`echo ${inputs[*]} | sed "s@[ ]*[^ ]*/@_@g"`_

align_image_stack -a /mnt/ram/${prefix} ${inputs[*]}

enfuse -o $output /mnt/ram/${prefix}*.tif

rm -f /mnt/ram/${prefix}*.tif

# fixme because hugin 2011.04 creates buggy jpg currently
convert $output $output
</code>


==== LuminanceHDR/Qtpfsgui ====

  * create new HDR
  * Choose profile ???
  * Choose operator:
    * mantiuk 06
      - adjust saturation and pre-gamma to get right color
      - adjust contrast and détails to get something realistic (less contrast and more details is more realistic)
  * adjust levels

==== Gimp ====

    * open middle image, rename layer "middle"
    * open dark image, copy content, create layer "dark" in middle image, paste content, anchor
    * desaturate dark image, adjust curves (white is opaque), copy content, add layer mask in "dark" layer, paste content
    * open bright image, copy content, create layer "bright" in middle image, paste content, anchor
    * desaturate bright image, adjust curves (black is opaque), invert, copy content, add layer mask in "bright" layer, paste content