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board pattern, which has n-1 elements of the same size and
one element, which has a size 4P-times larger than the size
of one of the other elements.
P is called perception value and is element of 2/4,3/4,4/4, 00 «
n is the number of significant elementary object images in the
image section Gp.
4P must be always less n.
The amount of area of the mask M must not be greater than
Crea" ] £4. If F, calculated from the equation above,,
is greater than Cre" y, then the according image
Structure should not be called a texture.
The maximum amount of the area of the mask is derived from the
following demand:
If a stripe structure is given, where the operator D is charac-
terized by a sinus function, this stripe structure should be a
texture, if there is a profile through Gg with at least one full
sinus phase.
Besides the two conditions T1 and T2 a third condition is necessa-
ry for a image structure to be a texture:
T3 If an image structure is texture for a perception value P1
with a significance factor c, then the image structure will
be a texture too for a perception value P1+1/4.
If an image structure is texture for a significance factor c1
with a percéption value P, then the image structure will be
a texture too for each significance factor greater cl.
If the conditions T1, T2 and T3 are satisfied, an image structure
is called a texture with perception value P and significance fac-
tor Ce
The size of the mask M is calculated from shape parameters so that
the definition of "texture" is derived from the shape parameters.
So the shape parameters, whieh supply the "density variance" para-
meters, to which the parameters of Haralick belong, are of great
importance for characterizing textures.
5. The significance of the texture definition given in 4. for
image analysis in geosciences
Before the shape parameters can be computed, the elementary ob-
ject' images have to be filtered out by a method of matched fil-
tering or by aid of equidensities. By smoothing the image before
filtering the finest structures can be eliminated, if desired.
Now analysing textures by aid of shape parameters is analysing
properties and arrangement of significant elementary object ima-
ges and the results of measurements of these properties can be
transferred to the image significant objects on the earth surface.
According as good the correlation between measurable properties
of the significant elementary object images and the appropriate
measurable properties of those objects on the earth surface, which
are interesting for the interpreter, texture parameters can be
measurable parameters for these objects.