HDR Images Vs. Standard Images
Written by: Jason Dick
Photos by:
Nathaniel,
Marcus
Tan, and
Connie
High
Dynamic Range imaging (HDR or HDRI) is a series of
new photography technologies revolutionizing the
quality of digital images.
HDR is important because real world
scenes contain light ranges usually exceeding
50,000:1 dynamic range. For the last thousand years,
media has been limited to around 300:1 dynamic
range. HDR imaging allows the photographer to
replicate the tonal ranges available in real life.
Photographers and artists alike from El Greco,
Monet, W. Eugene Smith and Ansel Adams have been
trying to reproduce the tonal ranges of images. But,
with the evolution of digital HDR an even greater
range is possible without nearly the effort.
The transition to HDR imaging will affect all
aspects of image creation, including capture,
storage, editing and output.
Capture:
The most common way for photographers to capture
high dynamic range images is to merge multiple
images into one to increase the dynamic range. This
is done by taking multiple photographs at different
exposures and merging them together to create a
single high-dynamic range image. The product,
HDRCapture simplifies this process by taking up to
15 exposures at the same time.
Storage:
Traditional image storage formats such as JPEG and
GIF provide only 8 bits/color channel and less
possibility for tonal range, making them unsuitable
for HDR photos. However, newer formats such as
JPEG2000, RAW and PNG offer 16 bits per channel.
HDRCapture stores images automatically in RAW
format.
Editing:
There are three main issues photographers must
consider when editing images: representing
brightness levels, creating graphical user
interfaces for HDR editing and image size.
Currently, it rendering images in a brightness level
that is too great for the monitor to show is an
unresolved issue at many times. Representing
graphical images for editing can be difficult
because the color ranges can go from 0 to several
million making it difficult to graphically represent
the middle ranges. HDR imaging also creates images
up to four times larger then normal images. This
makes editing very time consuming. Photographic
technologies will have to be adopted to help deal
with these issues.
Output:
Today, some digital displays have up to a 2,000:1
dynamic range. This trend of increasing dynamic
range will continue.
Benefits and Uses of HDR Photography:
Today, the majority of HDR users are specialized
professionals in film, animation and virtual reality
industries. HDR imaging is very useful for turning
graphic computer objects into images in real scenes.
Creating panoramic images with wide dynamic ranges
is another great use for HDR imaging. Another use of
HDR imaging is in computer gaming. Recent computer
graphics cards support HDR texture maps. As
photographic technologies continue to improve, the
greatest use for HDR imaging will most likely end up
being consumer photography.
In the next decade, HDR imaging technology will
revolutionize the way images are stored,
manipulated, used, and displayed, forever.
About the Author
Jason Dick is a technology expert and web author who
works for eAcceleration Corporation in the Seattle,
Washington area. He has been taking photographs for
over 30 years and recently began writing articles
for HDRCapture.
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