Procedure ConvertJPGtoBMP;
var
jpeg: TJPEGImage;
bmp: TBitmap;
Begin
jpeg:= TJPEGImage.Create;
try
jpeg.LoadFromFile( filename );
bmp:= TBitmap.Create;
try
bmp.Assign( jpeg );
bmp.SaveTofile( ChangeFileExt( filename, ‘.BMP’ ));
finally
bmp.free
end;
finally
jpeg.free
end;
end;

uses jpeg;

procedure ConvertBMPtoJPG;
var
bmp : TImage;
jpg : TJpegImage;
begin
bmp := TImage.Create(nil);
jpg := TJpegImage.Create;
bmp.picture.bitmap.LoadFromFile ( ‘c:\picture.bmp’ );
jpg.Assign( bmp.picture.bitmap );
// Here you can set the jpg object’s properties as compression, size and more
jpg.SaveToFile ( ‘c:\picture.jpg’ );
jpg.Free;
bmp.Free;
end;