[hermes_32]

Por cierto, no ha sido muy dificil encontrar una solucion a lo que se preguntaba al principio del post.

BMP a JPG

Código Delphi [-]
procedure TForm1.BMPtoJPG(const FileName: TFileName);
var
  jpeg: TJPEGImage;
  bmp:  TBitmap;
begin
  bmp := TBitmap.Create;
  try
    bmp.LoadFromFile(FileName);
    jpeg := TJPEGImage.Create;
    try
      jpeg.Assign(bmp);
      jpeg.SaveTofile(ChangeFileExt(FileName, '.jpg'));
    finally
      jpeg.Free
    end;
  finally
    bmp.Free
  end;
end;

JPG a BMP

Código Delphi [-]
procedure tform1.JPEGtoBMP(const FileName: TFileName);
var
  jpeg: TJPEGImage;
  bmp:  TBitmap;
begin
  jpeg := TJPEGImage.Create;
  try
    jpeg.CompressionQuality := 100; {Default Value}
    jpeg.LoadFromFile(FileName);
    bmp := TBitmap.Create;
    try
      bmp.Assign(jpeg);
      bmp.SaveTofile(ChangeFileExt(FileName, '.bmp'));
    finally
      bmp.Free
    end;
  finally
    jpeg.Free
  end;
end;