From: Jens Gruschel <jens@pegtop.de>
Subject: Re: Loading Images From Stream
Date: 07 Sep 1999 00:00:00 GMT
Message-ID: <37D547A5.687DA229@pegtop.de>
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Hi Petr!

Try something like this to write your images to a BIG file:
(instead of JPGs you can use Bitmaps, too, just replace JPegImage with Bitmap)

Var
  TempJPegImage: TJPegImage;
  TempFileStream: TFileStream;

TempFileStream := TFileStream.Create(FileName,fmCreate OR fmShareDenyWrite);
Try
  TempJPegImage := TJPegImage.Create;
Try
    TempJPegImage.LoadFromFile (ImageName);
    TempJPegImage.SaveToStream (TempFileStream);
  Finally
    TempJPEGImage.Free;
  End;
Finally
  TempFileStream.Free;
End;

And to load them again:

TempFileStream := TFileStream.Create(Globals.SLIFileName,fmOpenRead OR
fmShareDenyWrite);
Try
  TempJPegImage := TJPegImage.Create;
  Try
    TempJPegImage.LoadFromStream (TempFileStream);
    Whereever.Canvas.Draw (0,0,TempJPegImage);
  Finally
    TempJPegImage.Free;
  End;
Finally
  TempFileStream.Free;
End;

If you have more than one image stored in your BIG file (I guess you have), a
file position table might help.
All you need is an array (if you don't know how many images there are better
solutions than this one) like this:

Var
  ImageTable: Array[0..99] of LongInt;

before you save the the first image to the stream:
  TempFileStream.Position := NumberOfImages*SizeOf(LongInt);

before you save a single image to the stream:
  ImageTable[i] := TempFileStream.Position;

before you close the stream:
  TempFileStream.Position := 0;
  TempFileStream.Write (ImageTable,NumberOfImages*SizeOf(LongInt));

for reading the images again, first read the table (once in FormCreate?) and
set the Position of the Stram.

Hope this helps...
Jens