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Figure 2.1 Homogeneous residential sectors. Sao Jose 
dos Campos, SP, Brazil, 1977. 
Figure 2.1 shows an example of the result of the 
delineating process for residential sectors through 
the differentiation of the photographic textures. 
This aerial photograph clearly shows the 
differences between the textures 1, 2, 3 and 4 which 
are marked and allow the definition of four urban 
residential sectors. 
Texture 1 is coarser than the other ones, i.e. its 
primary elements are larger. It is defined by a few 
large houses and large lots, many of which still 
unoccupied, spatially organized along the streets 
that constitute the road system of the sector that 
is regular, with parallel lines ending up in 
"dead ends". 
Texture 2 introduces a more heterogeneous 
composition as far as its component elements are 
concerned. It is an urban reneval area in which can 
be seen large-size apartment houses, side-by-side 
with one-storey houses. Such elements are matched 
according to a spatial organization pattern that 
gives the area an overall homogeneous appearance. 
Texture 3 is slimmer, i.e. made up from primary 
elements smaller than in the preceding texture. It 
is defined by one-family houses, smaller than the 
ones in the areas of the previous textures. The 
occupation is dense, not only because of the 
relationship, per area, between constructed and 
empty areas, inside the lot, but also because there 
are hardly any unoccupied lots left. 
Texture 4 is defined by the presence of slightly 
larger houses than the ones described in the texture 
3 area. Furthermore, there are many unoccupied areas, 
as well as a great deal of arborization, which gives 
the area an aspect that is well-differentiated from 
that of the previous areas. 
The delineating of homogeneously-texture 
residential areas is a task that depends on the 
photointerpreter's capacity for discriminating 
between determined simpler textures and, by means of 
more developed cognitive processes, discriminating 
between more complex textures. The execution of this 
task requires not only the study of 
photointerpretation techniques, but also specific 
knowledge of architecture and urbanism.