function ImageNegativeKetupat pada pengolahan citra digital

function ImageNegativeKetupat(MInput:Matriks):Matriks;
var
    i,j,l,s,r:integer ;
    MOutput : Matriks ;
begin
    SetLength(MOutput,Length(MInput), Length(MInput[0]));
    if Length(MInput)<Length(MInput[0]) then
      l:= Length(MInput)div 2
    else
      l:= Length(MInput[0])div 2 ;

    s:=(Length(MInput[0])div 2)-l;
    r:=(Length(MInput)div 2) - l;

    for i := 0 to Length(MOutput)-1 do
    begin
        for j:= 0 to Length(MOutput[0])-1 do
        begin
            MOutput[i,j] := MInput[i,j]   ;
            if ((i-r)+(j-s) >= l) and ((j-s)<=l+(i-r)) and ((i-r)<= l+(j-s) ) and ((i-r)+(j-s) <= length(MOutput)+l) and ((i-r)+(j-s) <= length(MOutput[0])+l) and (i>=r) and (j>=s) then
                 MOutput [i,j] := 255 - MInput[i,j]
        end;
    end;
    ImageNegativeKetupat := MOutput ;
end;