International Archives of Photogrammetry and Remote Sensing, Vol. 32, Part 7-4-3 W6, Valladolid, Spain, 3-4 June, 1999
189
inventory maps. The total length of the forest inventory stand
borders was 30,380 m.
Figure 4 shows the visibility result for the first interpreter: the
total stand border length from inventory maps is set to 100%
visible (best). In every image product more than 71% of the
stand borders could be detected, whereby IHS_TM showed
worst visibility. The visual part of the delineation increased in
the following order: Pan, IHS_SP, Ortho and achieved
maximum percentage at Qsim with 88%.
Fig. 4. Visibility percentage of stand borders of interpreter 1.
Figure 5 shows a comparison of the visibility for 3 image
products and two interpreters. For both interpreters the visibility
percentage is increasing from IHSJTM to Pan and Qsim. The
class partial visible is decreasing with increasing geometric
resolution of the image product. It is important to point out, that
the fused IHS_TM achieves worse visibility than the single Pan
image, i.e. in this case the fusion did not lead to enhanced
information for visual analysis.
Fig. 5. Comparison of stand border delineation of two
interpreters with 3 image products.
On the other hand, IHS_SP with the combination of IHS and
AIF transformed SPOT data showed better results than the
panchromatic image alone (Figure 4).
3.2. Calculation of quality measure criteria
The buffer method was used with 3 buffer widths (2.5m, 5m and
10m). Only results with 10m will be presented here (10m is an
acceptable delineation accuracy, as defined by the forest
administration). Table 5 shows the result for correctness for
interpreter 1: total delineation is the total length of all visually
extracted stand borders and matched delineation is the total
length of the stand borders inside the buffer around the
reference.
Interpreter 1
PAN
1HS_TM
IHSJP
ORTHO
QSIM
Matched Delineation
19867
17554
20347
22557
23117
Total Delineation
23259
22558
23958
25610
26625
Correctness
0.85
0.78
0.85
0.88
0.87
Table5. Calculated correctness results from interpreter 1.
(delineation in m).
The best results for correctness were achieved by interpreter 1
with Ortho and Qsim with 88% and 89 % respectively, followed
by IHS_SP and Pan with 85%. IHSJTM achieved the worst
result with 78%. Interpreter 2 achieved the best results with
Qsim with 78%, followed by IHSJTM with 74% and Pan with
70%. So, the results of interpreter 2 were ca. 10% less accurate
than the ones of interpreter 1.
Table 6 shows the result for completeness for interpreter 1: total
reference is the sum of all stand borders, and matched reference
is the percentage of the reference network within the buffer
around the delineated data.
Interpreter 1
PAN
IHS_TM
IHS_SP
ORTHO
QSIM
Matched Reference
21248
21003
23383
23267
23185
Total Reference
30380
30380
30380
30380
30380
Completeness
0.70
0.69
0.77
0.77
0.76
Table 6. Calculated completeness results from interpreter 1
(delineation in m).
The best results were obtained with IHS_SP, Ortho and Qsim
with 0.77 and 0.76. The worst result again with IHSJTM.
Table 7 shows the result for quality for interpreter 1. Best results
were achieved with Qsim and Ortho with 0.68 and 0.69
respectively, IHS_SP is medium and again IHSJTM provided
the worst quality.