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;