Определить формат изображения, загруженного в TMemoryStream
Материал из DRKB
type
TImageType = (NoImage, Bmp, Gif, Gif89, Png, Jpg);
function KindOfImage(Start: Pointer): TImageType;
type
ByteArray = array[0..10] of Byte;
var
PB: ^ByteArray absolute Start;
PW: ^Word absolute Start;
PL: ^DWord absolute Start;
begin
if PL^ = $38464947 then
begin
if PB^[4] = Ord('9') then
Result := TImageType.Gif89
else
Result := TImageType.Gif;
end
else if PW^ = $4D42 then
Result := TImageType.Bmp
else if PL^ = $474E5089 then
Result := TImageType.Png
else if PW^ = $D8FF then
Result := TImageType.Jpg
else
Result := TImageType.NoImage;
end;
Пользоваться можно так:
case KindOfImage(MemoryStream.Memory) of ...
Для тех, кого смущает absolute:
type
TImageType = (NoImage, Bmp, Gif, Gif89, Png, Jpg);
function KindOfImage(Start: Pointer): TImageType;
begin
if LongWord(Start^) = $38464947 then
begin
if (PChar(Start) + 4)^ = '9' then
Result := TImageType.Gif89
else
Result := TImageType.Gif;
end
else if Word(Start^) = $4D42 then
Result := TImageType.Bmp
else if LongWord(Start^) = $474E5089 then
Result := TImageType.Png
else if Word(Start^) = $D8FF then
Result := TImageType.Jpg
else
Result := TImageType.NoImage;
end;
Author: s-mike
Source: http://forum.sources.ru
ID: 03631
ID: 03633