Image Processing Reference
Another open-source program to create HDR images is Qtpfsgui, now called
Luminance HDR , which can be found at: http://qtpfsgui.sourceforge.ne t/ .
The program is available for all three major operating systems. For
Windows, you will need to install additional DLLs. If you're interested in
this program, you should read the details on the website at http://qtpfsgui.
sourceforge.net/download.php or on the downloaded readme file.
FDRTools is another program for creating HDR images, and it's available
for Mac OS and Windows. The free version of the program, FDRTools Basic ,
can be downloaded at http://www.fdrtools.com/front_e.php, or you can find
it on this topic's DVD. It is worthwhile to read the tutorials on the website. All
basic information, prerequisites, and work steps are described in great detail.
In my experience, this program offers, even in the basic version, better editing
possibilities and results than most professional image editing software for
Adobe Photoshop, of course, is a very well-known commercial software
that includes the functionality to create HDR images. Starting at version CS2,
it can merge pictures into HDR images. You can also use Photomatix Pro from
Hdrsoft ( http://www.hdrsoft.co m ). Both programs offer free test versions.
Beware, though, that the Adobe Photoshop download is about 980 MB and
Photomatix is about 3 MB.
3.15.3 Cross-Fading Part 3—Merging Images
into one Pseudo HDR
GIMP doesn't offer any features for merging HDR images. However, I would like
to show you a method to reach similar results. Actually, it is used to cross-fade
parts of images, letting you merge images, but you can also merge bracketed
photos with this method. In addition, you can create the basis for a pseudo
HDR image by editing one preferably underexposed image with the tonality
corrections in three different variations, saving each variant as a new image.
In the SampleImages folder on the DVD you will find a subfolder named
Exposure Bracketing. Included you will find the RAW files DSCN0832.NEF ,
DSCN0833.NEF , and DSCN0834.NEF . For this example, I have developed these
RAW images as median.png , details-shadows.png , and details- highlights.png ,
which are also included in the subfolder. The first image was taken with normal
exposure settings and serves as the reference image. The second image is
overexposed. This is required so that darker parts of the image appear lighter.
The last image is underexposed, but it shows the most details in the brighter
parts of the picture.