The cameras are meant to acquire the description of the scene in visual
terms. We will not be addressing other descriptors, such as audio or other
sensory signals, but only the visual side of it. So the visual information
is what will be acquired, and for that we will have a suit of cameras
at the scene which will be acquiring information about the scene in various
ways.
Traditionally these cameras have four attributes that make them good or
bad, meaning they represent strengths and weaknesses at the same time,
where if the camera does well in anyone of them it may not be doing equally
well in others.
First, the dynamic range attribute refers to the camera's ability to capture
the entire brightness present in the scene. So if you look here the scene
has a very large range of brightness. There is the background far behind
the tree, which is very bright. At the same time the tree leaves and the
tree branches are not getting any of light to be seen in detail where,
when the camera is at the same time also trying to get information about
the brightness in the far region.
Now, most cameras that we are familiar with have the property that they
cannot simultaneously get detail in this entire range of brightness. And
therefore usually we would like to arrange the scene to be seized at,
that it is either very bright or very dark, and we adjust as uniformly
bright or dark, or not to the range of brightness values is not too broad
and, once we know what range, it is we can adjust our camera parameters
so that it is more sensitive to that range.
So when the range is too large like here, then the camera does not capture
the detail on either end. In fact, it really captures the entire range
badly. In summary, this feature refers to the small breadth of sensitivity
range that the camera has, and in practice that sensitivity range has
to be tuned to one particular interval on the scene brightness range,
only that interval is captured well. The rest is either clipped at the
bottom or at the top under exaggerated exposure or over exaggerated exposure.
This is one attribute in which cameras need to be performing well, namely
regardeless of the brightness range of the scene. The ideal thing would
be for them to capture the scene brightness to provide an image such that
we do not loose any of the details.
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