Bitmap data extraction (matrix of matrix)

• To: mathgroup at smc.vnet.net
• Subject: [mg76445] Bitmap data extraction (matrix of matrix)
• From: mkorneck at nd.edu
• Date: Tue, 22 May 2007 02:54:57 -0400 (EDT)

```Hello,

This is most likely a simple question for those who use Mathematica on
a semi-regular basis, but ...

I have a 512x512 matrix composed of 1x3 matrix elements, and want to
create a 512x512 matrix composed of a single value in the original 1x3
elements.

That doesn't look very well defined, so please let me explain further
in the hopes of clarifying what I am after.

It's a bitmap image file (512x512) and I want to extract a part of the
"raw" data for further processing. The raw data in the original file
consists of values for the red, green and blue (RGB). I would like to
create a matrix composed of only the *red* values across the 512x512
array.

As a simplified example ....

Given RGB = {{1,0,1},{2,3,2},{4,6,4},{3,2,1}}
{{9,1,3},{3,2,1},{4,3,3},{5,3,2}}

I would like to end up with R = {1,2,4,3}
{9,3,4,5}