ABSTRACT
At these levels of resolutions and in a context of dense urban tissue, there are a considerable number of hidden parts to the extent that a dense and thorough description of the scene by a stereo analysis is limited (Figure 3.3.29). Besides in urban areas, the classical stereo processing admits some flaws due to all the matching ambiguities encountered, e.g. mobile vehicles (Figure 3.3.30), repetitive structures and also due to the poor image quality. Poor image quality for instance in scanned images is due to noise added by the scanning process, to the dust, the scratches, and other dirt present on the silver halide photographs, but also due to the non-linearity of the silver halide sensibility. Indeed, the signal to noise ratio is dreadful in dark areas such as shadows, which will thus have poor chances of being matched if they are hard.
