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Re: Convert Binary Image to Column Vector

  • To: mathgroup at smc.vnet.net
  • Subject: [mg83972] Re: Convert Binary Image to Column Vector
  • From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
  • Date: Thu, 6 Dec 2007 02:35:52 -0500 (EST)
  • Organization: The Open University, Milton Keynes, UK
  • References: <fj65hr$fp1$1@smc.vnet.net>

Tara.Ann.Lorenz at gmail.com wrote:

> Can a 30x30 binary image be converted directly into a column vector of
> 900 components in Mathematica? 

Yes.

Either Flatten@t1 or Flatten@Transpose@t1 will do the job, though the 
elements will be put in different order (see an example below).

 > Or must the image first be put into matrix form?

No.

And if by "matrix form" you mean MatrixForm, never do that for 
MatrixForm must be reserved just for display purpose.

 > I am using the command:
>  Flatten@Transpose@t1, where t1 is my binary image, and it seems to
> give me a vector but I'm not sure if it's the one that I desire.

The following examples illustrate the differences between the outputs 
produced by Flatten@t1 and Flatten@Transpose@t1, respectively.

Mathematica 6.0 for Microsoft Windows (32-bit)
Copyright 1988-2007 Wolfram Research, Inc.

In[1]:= t1 = {{a, b}, {c, d}};

In[2]:= t1 // MatrixForm

Out[2]//MatrixForm= a   b

                     c   d

In[3]:= Flatten@t1

Out[3]= {a, b, c, d}

In[4]:= Flatten@Transpose@t1

Out[4]= {a, c, b, d}

<snip>

Regards,
-- 
Jean-Marc


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