function img = pfs_read_image( fileName )
%PFS_READ_IMAGE Read image file and return RGB, luminance or multichannel matrix.
%
% IMG = PFS_READ_IMAGE( file_name )
%
% If input is a gray-scale or luminance image, IMG is a 2D matrix. If input is
% a color image, IMG(:,:,k) represents red, blue and green color channels for k=1,2 and 3.
% If input is a multi-channel image (channel names C1, C2, ..., Cn), IMG is a
% 3D matrix with 3rd dimension corresponding to the channels.
%
% PFS_READ_IMAGE accepts all formats recognized by the shell "pfsin"
% command.
%
% Example:
% img = PFS_READ_IMAGE( 'hdr_images/memorial.exr' );
%
% See also: PFS_READ_RGB, PFS_READ_LUMINANCE, PFS_READ_XYZ,
% PFS_WRITE_IMAGE, PFSVIEW.
%
% Copyright 2009 Rafal Mantiuk
%Check if file exists
fid = fopen( fileName, 'rb' );
if( fid == -1 )
error( 'pfs_read_image: File "%s" does not exist', fileName );
end
fclose( fid );
fid = pfspopen( sprintf( '%spfsin ''%s''%s', pfs_shell(), fileName, pfs_shell( 1 ) ), 'r' );
pin = pfsopen( fid );
pin = pfsget( pin );
if( isfield( pin.channels, 'X' ) && isfield( pin.channels, 'Z' ) )
img = pfs_transform_colorspace( 'XYZ', pin.channels.X, pin.channels.Y, pin.channels.Z, 'RGB' );
elseif( isfield( pin.channels, 'Y' ) )
img = pin.channels.Y;
elseif( isfield( pin.channels, 'C1' ) )
ch=1;
% count the number of channels
while( isfield( pin.channels, sprintf( 'C%d', ch ) ) )
ch = ch+1;
end
ch_max = ch-1;
img = zeros(pin.rows, pin.columns, ch_max);
for ch=1:ch_max
img(:,:,ch) = pin.channels.(sprintf( 'C%d', ch ));
end
else
error( 'Color channels missing in the pfs frame' );
end
pfsclose( pin );
% TODO: Check why crashes on windows
if ~ispc()
pfspclose( fid );
end
end
I found this program on the internet but I don't really understand it but I just want to use this part
% count the number of channels
while( isfield( pin.channels, sprintf( 'C%d', ch ) ) )
ch = ch+1;
end
ch_max = ch-1;
img = zeros(pin.rows, pin.columns, ch_max);
for ch=1:ch_max
img(:,:,ch) = pin.channels.(sprintf( 'C%d', ch ));
end
but I don't really know how to do it.
