First of all, I am not a photographer, nor related to the professional photography, nor even having a digital camera.
I've seen lots of photos in my life. Surfing the web, I even discovered several techniques to improve the visual impact of a photo. Visual impact doesn't mean only to boost the contrast of picture's color, but to send a much "visible" message to the viewer.
Since I am not professionally related to the image processing and not even owning a digital camera, I am more than a stranger to the daily tasks that an amateur to a professionally photographer is currently performing when is processing images.
But sometimes, I was questioning myself if it is possible to get from a picture more than we currently see in it. Some of the photos I've seen were good (as far as I can tell as a common viewer) and most of them were bad: not having the proper exposure, lot of blurring due to the lack of a tripod or anything to keep the camera still, vignetting, noise and other image flaws.
Sometimes I was picturing in my mind that someone could have better results if he will use the same picture, but taken in different conditions: under or overexposed, in order to get the picture to the same visual level as a human eye can do it.
Of course this is not possible with the current cameras in one shot only, but we can make the picture in 3 different exposures: under, normal and overexposed. Then, from each of these, we will extract the details we need.
Today I've found that there is such a technique, and is used to make HDR pictures (highdynamicrange).
Look at these photos:
There is nothing to not like them.
And those picture were made with the same technique I've just dreamed of: taking the same picture with 3 different exposures, and then combining into a image processing software as Photoshop or Photomatix.
More of these picture here: http://flickr.com/groups/bestofhdrpictures/pool/
You can search the net for HDR making techniques, as there are available few good tutorials.