You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: im2col_mine.m
    path of file: ./repos/OpenFace/matlab_version/fitting
    
    the code of the file until where you have to start completion: function b=im2col_mine(a, block)
%IM2COL Rearrange image blocks into columns.
%   B = IM2COL(A,[M N],'distinct') rearranges each distinct
%   M-by-N block in the image A into a column of B. IM2COL pads A
%   with zeros, if necessary, so its size is an integer multiple
%   of M-by-N. If A = [A11 A12; A21 A22], where each Aij is
%   M-by-N, then B = [A11(:) A21(:) A12(:) A22(:)].
%
%   B = IM2COL(A,[M N],'sliding') converts each sliding M-by-N
%   block of A into a column of B, with no zero padding. B has
%   M*N rows and will contain as many columns as there are M-by-N
%   neighborhoods in A. If the size of A is [MM NN], then the
%   size of B is (M*N)-by-((MM-M+1)*(NN-N+1). Each column of B
%   contains the neighborhoods of A reshaped as NHOOD(:), where
%   NHOOD is a matrix containing an M-by-N neighborhood of
%   A. IM2COL orders the columns of B so that they can be

    
function b=im2col_mine(a, block)
%IM2COL Rearrange image blocks into columns.
%   B = IM2COL(A,[M N],'distinct') rearranges each distinct
%   M-by-N block in the image A into a column of B. IM2COL pads A
%   with zeros, if necessary, so its size is an integer multiple
%   of M-by-N. If A = [A11 A12; A21 A22], where each Aij is
%   M-by-N, then B = [A11(:) A21(:) A12(:) A22(:)].
%
%   B = IM2COL(A,[M N],'sliding') converts each sliding M-by-N
%   block of A into a column of B, with no zero padding. B has
%   M*N rows and will contain as many columns as there are M-by-N
%   neighborhoods in A. If the size of A is [MM NN], then the
%   size of B is (M*N)-by-((MM-M+1)*(NN-N+1). Each column of B
%   contains the neighborhoods of A reshaped as NHOOD(:), where
%   NHOOD is a matrix containing an M-by-N neighborhood of
%   A. IM2COL orders the columns of B so that they can be
%   reshaped to form a matrix in the normal way. For example,
%   suppose you use a function, such as SUM(B), that returns a
%   scalar for each column of B. You can directly store the
%   result in a matrix of size (MM-M+1)-by-(NN-N+1) using these
%   calls:
%
%        B = im2col(A,[M N],'sliding');
%        C = reshape(sum(B),MM-M+1,NN-N+1);
%
%   B = IM2COL(A,[M N]) uses the default block type of
%   'sliding'.
%
%   B = IM2COL(A,'indexed',...) processes A as an indexed image,
%   padding with zeros if the class of A is uint8 or uint16, or
%   ones if the class of A is double.
%
%   Class Support
%   -------------
%   The input image A can be numeric or logical. The output matrix
%   B is of the same class as the input image.
%
%   Example
%   -------
%   Calculate the local mean using a [2 2] neighborhood with zero padding.
%
%       A = reshape(linspace(0,1,16),[4 4])'
%       B = im2col(A,[2 2])
%       M = mean(B)
%       newA = col2im(M,[1 1],[3 3])
%
%   See also BLOCKPROC, COL2IM, COLFILT, NLFILTER.

%   Copyright 1993-2012 The MathWorks, Inc.

[ma,na] = size(a);
m = block(1); n = block(2);

if any([ma na] < [m n]) % if neighborhood is larger than image
    b = zeros(m*n,0);
    return
end