We present 3 solutions to this problem:
  mp1sol.m   is the solution as required by the MP1 document
  mp1sol2.m  is a solution that DOES NOT conform to the MP1 document but shows
             how one can use the rgb2gray function
  mp1sol3.m  is a solution that DOES NOT violate the MP1 document but goes
             beyond what was/is expected of the students for this MP1.


A. Official solution : mp1sol.m

Idea: (0,0,0) is black, (255,255,255) is white. We are going to convert  every pixel
      to a triplet (X,X,X) where X is either the R or G or B component of that pixel.

newpict(:,:,1)=newpict(:,:,3) 
newpict(:,:,2)=newpict(:,:,3) 

Use the Blue (layer 3) contribution and make the Red and Green values equal to it.
This ways R,G,B values for all pixels are the same as the B values.

Alternately you could have used the R or G contributions, as shown below for R.

newpict(:,:,3)=newpict(:,:,1) 
newpict(:,:,2)=newpict(:,:,1) 

Note that the solution file is mp1sol.m . Your submission should have used a
file named MP_1_WXYZ.m where WXYZ are the last 4 digits of your NJIT ID.

B. Non-conforming solution : mp1sol2.m 

As we mentioned in the assignment there is an easy way to solve this problem using
rgb2gray. This is done in mp1sol2.m  . Note that for a gray (i.e. black-and-white) image,
one needs to use imshow to display it.  The function image displays a 3-layer image, whereas
imshow displays a 1-layer image. You can verify the number of layers in pict and newpict
by typing. whos.


C. Conforming solution : mp1sol3.m
 
How does rgb2gray work to turn a 3-layered into a 1-layered image? A simple 'implementation'
of something close to rgb2gray is the code in mp1sol3.m . You can see there a new form of the
zeros function. In newpict every pixel obtains a contribution of both red, green and blue.
The weights I use are not mine. I looked them up on the Web.  MATLAB's implementation of
rgb2gray is more complex. Type   type rgb2gray.m to find out how it works!