on 
ut 
also 
arlier) 
ach 
tive 
bi- 
tone 
yses 
es) 
  
ture 
es 
or 
use 
bles 
and 
op 
gating 
ne 
etter 
Table 4 
Summary of Success Scores of Tonal and Textural Variables in 
Combinations 
  
(For Five Crop Types) 
Variables 3-6 1,3-6 153,9 2,4,6 3,5 4,6 
Percentage 80$ 79% 66% 45% 45% 46% 
Successes 
ES — — — — — —— — — — — — — —— — — — — — — — —— — — — —  — — — — — — — — —— — —— — — —— —— —— 
(For Four Crop Types) 
Variables 3-6 1,3-6 5,6 3,4 1,2 
Percentage 88% 86% 75% 80% 62% 
Successes 
Variables: 1 = Tone Small Scale 2 = Texture Small Scale 
3 = Tone Medium Scale 4 = Texture Medium Scale 
5 = Tone Large Scale 6 = Texture Large Scale 
  
first three crop comparisons, is illustrated in the table, while 
in the last three crop comparisons, texture played almost an ex- 
clusive role in discrimination with little or marginal increase by 
use of tone in addition to texture. It is apparent that if only 
pairs of crops were to be discriminated, one scale (medium or large) 
was sufficient. Medium was better in some cases while the large in 
some others. This explains the improvement in overall success by 
use of both scales when all the crop types are to be discriminated 
simultaneously. (Wheat fields are not included in this summary as 
they are easily separated from all other crop types by tonal vari- 
ables alone at all the three scales independently). 
Tonal and Textural bivariate plots (figures 1 to 5) 
Figure 1 is a bivariate plot of tone and texture at small scale. 
There is little separation at the contact scale except between wheat 
and other crop types. 
Figure 2 is bivariate plot of tone and texture at the medium scale 
and Figure 3 is a similar plot at the large scale. The following 
should be noted: 
a) size of the ellipses are generally reduced as compared. to 
Figure 1 indicating reduction of variances; 
b) there is little correlation between tonal and textural variables. 
Thus texture provides additional information; 
c) the role of texture is supplementary as well as complementary 
to that of tone. This is particularly evident in the separation 
of corn crop from the idle fields and idle fields from the wheat 
fields.