用delphi比较两张图片的相似度

procedure TFrm_test.initList;
var
  idx, i, k, x, y, l: integer;
  p, fn: string;
  bmp: TBitmap;
  BColor, NowColor: TColor;
begin

  p := ExtractFilePath(Application.ExeName);
  bmp := TBitmap.Create;
  for i := 0 to 9 do
  begin
    fn := p + '\CodeBmp\ ' + IntToStr(i) + '.bmp ';
    if not FileExists(fn) then
      Continue;

    idx := length(PointRecList);
    SetLength(PointRecList, idx + 1);
    PointRecList[idx].Code := IntToStr(i);

    bmp.LoadFromFile(fn);
    BColor := bmp.Canvas.Pixels[0, bmp.Height - 1];

    for x := 0 to bmp.Width - 1 do
      for y := 0 to bmp.Height - 1 do
      begin
        NowColor := bmp.Canvas.Pixels[x, y];
        if NowColor <> BColor then
        begin
          l := length(PointRecList[idx].PointList);
          SetLength(PointRecList[idx].PointList, l + 1);
          PointRecList[idx].PointList[l].x := x;
          PointRecList[idx].PointList[l].y := y;
        end;
      end;

  end;

  FreeAndNil(bmp);

  //
end;

function getCode_Bmp(const bmp: TBitmap; strLen: integer;
  PointRecList: array of TPointRec): string;
var
  j, i, l, x, y, x0, xS, beginx: integer;

  BColor, NowColor: TColor;
  PointList: array of TPoint;
  function getCode: string;
  var
    maxCount, k, m, j, i: integer;

  begin
    Result := '? ';
    if length(PointList) < 3 then
      exit;

    maxCount := 0;
    for i := 0 to high(PointRecList) do
    begin

      if length(PointRecList[i].PointList) < 3 then
        Continue;

      m := 0;

      for k := 1 to high(PointList) do
      begin

        for j := 1 to high(PointRecList[i].PointList) do
          if ((PointList[k].x - PointList[0].x) =
              (PointRecList[i].PointList[j].x - PointRecList[i].PointList[0].x)
            ) and ((PointList[k].y - PointList[0].y) =
              (PointRecList[i].PointList[j].y - PointRecList[i].PointList[0].y)
            )

            then
          begin
            inc(m);
            Break;
          end;

      end;

      m := m * 100 div (length(PointList) - 1);
      if m > maxCount then
      begin
        Result := PointRecList[i].Code;
        maxCount := m;
      end;
    end;
  end;

begin
  Result := ' ';
  BColor := bmp.Canvas.Pixels[0, bmp.Height - 1];
  x0 := 0;
  xS := bmp.Width div strLen;
  for i := 0 to strLen - 1 do
  begin
    beginx := x0 + xS * i;
    SetLength(PointList, 0);
    for j := 0 to xS - 1 do
    begin
      x := beginx + j;
      for y := 0 to bmp.Height - 1 do
      begin
        NowColor := bmp.Canvas.Pixels[x, y];
        if NowColor <> BColor then
        begin
          l := length(PointList);
          SetLength(PointList, l + 1);
          PointList[l].x := x;
          PointList[l].y := y;
        end;
      end;
    end;
    Result := Result + getCode;
  end;
end;