function grow()
% rr and rc can be any number provided they are greater than one and whole
% integers.
rr = 4; % ratio to multiply the rows by, i.e. rr = 2 doubles the amount of rows the new picture will have
rc = 4; % same as above but for columns

if( rr < 1  || rc < 1) % this program cannot yet downsize pictures!
    disp(' This program cannot downsize pictures, run function shrink() instead!');
end


nc = 235; %Image dimensions
nr = 300; %Other image dimensions

F = imread('watarunfullsmall.jpg'); % reads image from the same folder this matlab .M file is located
%H = imread('watarunfull.jpg');
%image(F);
%image(F);



X = zeros(rr*nr,rc*nc,3,'uint8'); % creates 3 dimensional array to replace the picture supplied earlier (columns,rows,rgb of type unsigned integer (8 bytes))

for i = 1:1:nr
    for j = 1:1:nc

        X(i*rr - rr + 1 ,j * rc - rc + 1,1:3) = F(i,j,1:3); % Copies color codes

    end
end


sir = splineInterpolationRows(X,nr,nc,rr,rc,1);
sic = splineInterpolationColumns(sir,nr,nc,rr,rc,1);

for i = 2:rc
sic = splineInterpolationColumns(sic,nr,nc,rr,rc,i);
end


image(sic);

%E = zeros(nr*rr,nc*rc,'uint8');
%for i = 1:1:nr*rr
  %  for j = 1:1:nc*rc
    %   for color = 1:3
    %    E(i,j,color) = abs(H(i,j,color) - sic(i,j,color)); % Copies color codes

    %   end
  % end
%end

%image(sic);
%imwrite(sic,'dogpixel Spline.jpg');

end



function sir = splineInterpolationRows(img,columnlength,rowlength,columnmultiple,rowmultiple,start)
degree = 1;
  for y = start:columnmultiple:columnlength*columnmultiple

  splinered = spline((1:rowmultiple*degree:rowlength*rowmultiple-rowmultiple*degree),...
      double(img(y,(1:rowmultiple*degree:rowlength*rowmultiple-rowmultiple*degree),1)));

  splinegreen = spline((1:rowmultiple*degree:rowlength*rowmultiple-rowmultiple*degree),...
      double(img(y,(1:rowmultiple*degree:rowlength*rowmultiple-rowmultiple*degree),2)));

  splineblue = spline((1:rowmultiple*degree:rowlength*rowmultiple-rowmultiple*degree),...
      double(img(y,(1:rowmultiple*degree:rowlength*rowmultiple-rowmultiple*degree),3)));

        for z = 1:rowmultiple-1
            for i = 1+z:rowmultiple:rowlength*rowmultiple-rowmultiple*degree-1

            img(y,i,1) = ppval(splinered, i);
            img(y,i,2) = ppval(splinegreen, i);
            img(y,i,3) = ppval(splineblue, i);
            end
        end
  end
sir = img;
end



function sic = splineInterpolationColumns(img,columnlength,rowlength,columnmultiple,rowmultiple,start)
degree = 1;
 for x = start:rowmultiple:rowlength*rowmultiple

       % xv = [1,1+rowmultiple,1+rowmultiple*2,1+rowmultiple*3];
       % yv = [img(y,xv(1),color),img(y,xv(2),color),img(y,xv(3),color),img(y,xv(4),color)];
        splinered = spline((1:columnmultiple*degree:columnlength*columnmultiple-columnmultiple*degree),double(img((1:columnmultiple*degree:columnlength*columnmultiple-columnmultiple*degree),x,1)));
        splinegreen = spline((1:columnmultiple*degree:columnlength*columnmultiple-columnmultiple*degree),double(img((1:columnmultiple*degree:columnlength*columnmultiple-columnmultiple*degree),x,2)));
        splineblue = spline((1:columnmultiple*degree:columnlength*columnmultiple-columnmultiple*degree),double(img((1:columnmultiple*degree:columnlength*columnmultiple-columnmultiple*degree),x,3)));



        for z = 1:columnmultiple-1

            for i = 1+z:columnmultiple:columnlength*columnmultiple-columnmultiple*degree-1

            img(i,x,1) = ppval(splinered, i);
            img(i,x,2) = ppval(splinegreen, i);
            img(i,x,3) = ppval(splineblue, i);


            end

        end
 end

sic = img;

end