[Страдалецъ]

Держите готовую утилю. Я сегодня добрый.

Код:

program JpgTran;

{$APPTYPE CONSOLE}

uses
  SysUtils,Graphics,JPeg;

Var
  Path: String;
  FileInfo: TSearchRec;
  FileNo,Width: Integer;
  Scale: Double;
  Jpg: TJpegImage;
  Bmp: TBitmap;
begin
 if ParamCount < 2
 then begin
      WriteLn('Example: JpgTran c:\jpglib\ 768');
      Exit;
      end;
 Path := Paramstr(1);
 Width := StrToInt(Paramstr(2));
 FileNo := 0;
 try
 if FindFirst(Path+'*.jpg',faAnyFile,FileInfo) = 0
 then repeat
      Inc(FileNo);
      Jpg := TJpegImage.Create;
      Jpg.LoadFromFile(Path + FileInfo.Name);
      Scale := Width / Jpg.Width;
      Bmp := TBitmap.Create;
      Bmp.Width := Round(Jpg.Width * Scale);
      Bmp.Height := Round(Jpg.Height * Scale);
      Bmp.Canvas.StretchDraw(Bmp.Canvas.ClipRect, Jpg);
      Jpg.Assign(Bmp);
      Jpg.SaveToFile(Format('%s%d.jpg',[Path,FileNo]));
      Bmp.Free;
      Jpg.Free;
      until FindNext(FileInfo) <> 0;
 except
  WriteLn('Error! Program aborted.');
  Exit;
 end;
end.