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JOURNAL OF COMPUTERS, VOL. 8, NO. 6, JUNE 2013 1525<br />
reliability of estimat<strong>in</strong>g leaves number with the use of<br />
snowflake theory is very high.<br />
curvature angle follow<strong>in</strong>g the ve<strong>in</strong> is very small, and we<br />
divide leaves with this k<strong>in</strong>d of features as shown <strong>in</strong> figure<br />
6(This is divided along the ve<strong>in</strong>s on the leaves), with the<br />
hypothesis that the rectangle divided out by us is <strong>in</strong> a<br />
plane.<br />
Figure 7. simulation of maple tree<br />
IV. SINGLE LEAF AREA ESTIMATION<br />
Ideas of model: we have classified leaf shapes <strong>in</strong> the<br />
above, so when we want to establish the model for leaf<br />
area estimation, we can f<strong>in</strong>d a representative leaf for<br />
analysis. In the process of analysis, ma<strong>in</strong>ly ideas of<br />
<strong>in</strong>tegration are used, <strong>in</strong> which, a reasonable division is<br />
given to leaves <strong>in</strong> different shapes <strong>in</strong> order to divided<br />
them <strong>in</strong>to graphics, of which areas can be calculated for<br />
analysis; Also considerations are gave to the bend<strong>in</strong>g<br />
problem of edges of leaves when the ve<strong>in</strong>s become closer<br />
to the central l<strong>in</strong>e at the middle of the leaves. For the<br />
calculation of this model each leave is segmented along<br />
with the ve<strong>in</strong>s of the leave.<br />
A. Flat Leaf<br />
Take a typical leaf, and draw its shape on a piece of a<br />
coord<strong>in</strong>ate paper. Take some po<strong>in</strong>ts from the draw<strong>in</strong>g and<br />
make a fitt<strong>in</strong>g to work out the leaf outl<strong>in</strong>e function with<br />
Least squares method. We can get the function images as<br />
shown <strong>in</strong> figure 8.Then we can calculate the leaf area S<br />
with curvil<strong>in</strong>ear <strong>in</strong>tegral:<br />
x2 x2<br />
∫ 1( ) ∫ 2( )<br />
(7)<br />
S = f x dx − f x dx<br />
x1 x1<br />
Figure 8. The simulation of flat leaf<br />
B. Curv<strong>in</strong>g Leaf<br />
Through observation we can f<strong>in</strong>d out that most of the<br />
curv<strong>in</strong>g of a leaf follows the ve<strong>in</strong> and towards the middle<br />
l<strong>in</strong>e, and the curv<strong>in</strong>g is gentle. The appearance of a bigger<br />
arc of curv<strong>in</strong>g is unusual, so we suppose that the<br />
Figure 9. The division of curv<strong>in</strong>g leaf<br />
This model can only make a rough estimation of the<br />
area of the curv<strong>in</strong>g leaf, and can only have an analysis on<br />
leaves with specific curv<strong>in</strong>g characteristics.<br />
C. Results of Model<br />
N is the number of the leaves on the tree;<br />
S is the area of a s<strong>in</strong>gle leaf;<br />
ρ is the surface density ;<br />
M is the weight of leaves on the maple tree.<br />
As for the maple used as an example, the number of<br />
the leaves simulated by computer belongs to<br />
[ 2187 , 2357 ].<br />
Accord<strong>in</strong>g to statistical data: the area of a s<strong>in</strong>gle leaf is<br />
about 52cm 2 , and the surface density is about 0.17g/cm 2 .<br />
Through calculation:<br />
M = ρ ⋅S⋅ N<br />
(8)<br />
The weight of the leaves on the maple tree is 19.3kg to<br />
20.8kg.<br />
We have used the method of factor analysis for<br />
cluster<strong>in</strong>g of leaf shapes to reduce the number of<br />
variables and simplify our research workload. We use a<br />
few public factors to expla<strong>in</strong> complicated relationships<br />
exist<strong>in</strong>g <strong>in</strong> more variables <strong>in</strong> observation. We use<br />
snowflake model to catch the law tree growth, well<br />
estimat<strong>in</strong>g the leaves quality of a tree. For the calculation<br />
the area of a s<strong>in</strong>gle leaf, not only the comparatively flat<br />
leaves are considered, but also the calculation of the area<br />
of leaf surface when there is the problem of surface<br />
curv<strong>in</strong>g.<br />
However because of time constra<strong>in</strong>ts, we couldn’t f<strong>in</strong>d<br />
out large amount of data for verify<strong>in</strong>g our theory.<br />
V. CONCLUSION<br />
Our ma<strong>in</strong> objective is about leaves quality research.<br />
First, we classify leaves based on different shapes, then<br />
simulate the processes of leaf growth and calculate total<br />
leaves per tree. Accord<strong>in</strong>g to the area and density of a<br />
leaf, we can easily estimate leaves weight of a tree.<br />
In the process of leaf shape classification, we firstly<br />
analyze the diversification of leaf shape. From the genetic<br />
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