Hi over there,

I'm not sure about your point, but let's discuss this:
If one takes a picture of a single leave of a lime ("lindenblatt.png") as an example, the following happens:

In[37]:= SetDirectory[NotebookDirectory[] <> "\\test"]
Out[37]= "N:\\Udo\\Abt_N\\test"

In[43]:= pofl = Import["lindenblatt.png"]

In[44]:= Clear
verts = ComponentMeasurements[pofl, "ConvexVertices"][[1, 2]];

In[47]:= verts
Out[47]= {{0., 536.}, {0., 0.}, {664., 0.}, {664., 536.}}

this is just a rectangle. 

In[50]:= Minimize[{Sin, Cos} - Rescale[[1]], t]
Out[50]= Minimize[{0. + Sin, -0.807229 + Cos}, t]

This did not work because Minimize[] minimizes a scalar-valued function, not a vector-valued function. One might use the Dot[] to get a scalar out of it

In[52]:= Minimize[({Sin, Cos} - Rescale[[1]]).({Sin, Cos} - Rescale[[1]]), t]
Out[52]= {0.0371607, {t -> -6.87155*10^-20}}

But what usage can you make out of it??

Greetings
Udo.