High Dynamic Range Imaging… my first steps…


I don’t own a 600 Euro digital camera. Mine was cheap and does the job well so far. And now I’ve found something more to play with. I like to do panoramic views, as you might have mentioned before. But the technique I am now discovering is far more interesting. It’s called High Dynamic Range imaging.

Here’s an excerpt of the wikipedia article on that subject:

In computer graphics and cinematography, high dynamic range imaging (HDRI for short) is a set of techniques that allow a far greater dynamic range of exposures than normal digital imaging techniques. The intention is to accurately represent the wide range of intensity levels found in real scenes, ranging from direct sunlight to the deepest shadows.”

Since it’s night here at the moment I could only experiment in the dark, where my camera creates, beside dark pictures, very much picture noise.

So, what to do, you may ask. Well grab a camera where you can control at least the exposure time. Than take at least 2 (the more the better) pictures with different exposure times. I started with 3 pictures per HDR image. As you can see above:

When you have those pictures you need a software to combine them to an HDR image. There are many sites that can provide such tools, I recommend hdrsoft.com. They provide a tool called “Photomatix” which is specialized on HDR imaging. If you have a Photoshop CS2 available, well, that will do the job as well. Just go to the “File->Automate->Create HDR” dialog.

If you downloaded the tools, throw the pictures inside and let the magic happen. You get a 16 or 32 Bit per pixel image. You can control the exposure and saturation, the white and the black levels and so on. To save the picture as a standard-JPG like I did, you have to do some Tone-Mapping. Photomatix can do that as well.

Expect more on that subject here tomorrow. Then with some pictures of the sunny nature…well if there is sun tomorrow…Till than: Enjoy the HDR images I’ve got so far:

First the 3 source pictures:

And then the HDRI:

First the 3 source pictures:

And then the HDRI:

Source 1: http://en.wikipedia.org/wiki/High_dynamic_range_imaging

Source 2: http://www.hdrsoft.com

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