825
impared
and Flight B 15,000 feet images (A 15,0 R1 vs B 15,0 Rl), and
the flight B 6,000 feet image and the repeat measurement of the
same image (B 6,0 Rl vs B 6,0 R2). Colors closely matching but
significantly different were the comparisons of the red image of
Flight B 6,000 feet as contained on two adjacent transparencies
(B 6,0 Rl and B 6,0 R2 vs B 6,0 R3). The view angle, especially
when one of the images is near the outer edges of the trans
>up being
parency as was the case in this study, can affect the color.
Most of this change is in terms of visual transmittance given by
the Y tristimulus value where a change from 68.92 to 63.72 is
noted (Table 2). The CIE-UCS u,v coordinates, however, differ
only at the fourth decimal place. Therefore, the chromaticness
differences are negligible even though the extremely low variance
values of this study provide a significant test difference.
i a F-
.ows:
For the green target, all comparisons were significantly differ
ent although the same tendencies exhibited by the red target were
evident. The Flight A and Flight B 15,000 feet images (A 15,0 G1
vs B 15,0 Gl) were quite similar as were the Flight B 6,000 feet
independent color determinations of the same image on two adjacent
transparencies (B 6,0 Gl vs B 6,0 G2). Also similar were the
Flight A and Flight B 1,500 feet images (A 1,5 Gl vs B 1,5 Gl).
observa-
For the white target, the 1960 CIE-UCS u,v coordinates for all
colors are so nearly the same that visually all images would be
judged to be almost clear of color. However, the nearly nil
variance terms associated with the image sample measurements
make an analysis possible although possibly somewhat question
able because of the unknown effects of slight equipment set-up
and calibration differences which are included in the measure
signific-
ment data. That this concern is warranted is attested to be the
fact that Flight B, 6,000 feet image and a repeat sample of the
same image (B 6,0 W1 vs B 6,0 W2) are significantly different
even though the difference was slight (Mahalanobis 1 D 2 = 2.55).
Nevertheless, the Flight A and Flight B 1,500 feet images are
not significantly different (A 1,5 W1 vs B 1,5 Wl) continuing
the pattern for the images at 1,500 and 15,000 feet to be nearly
the same color respectively on each of the flight dates.
1 sample
il value
COLOR SHIFTS
>ns were
Imaged Red Target
Reference to Table 2 and Figure 3 (2x enlargement insert) shows
an altitude associated color shift toward blue-green for the red
imaged target which appears as a saturated yellow color on the
transparencies. The changes in the visual transmittance given
by the tristimulus Y value and the analytical density of the
ltly dif-
Light A
yellow, magenta and cyan dye layers on the different Flight
dates-altitude combinations may be partially explained by the