struct _RGB
{
        byte R;
        byte G;
        byte B;
};

void __fastcall TForm1::ConverToGray()
{
        double Y;
        _RGB col;
        void *pict_line;

        for (int i= 0 ; i<Image1->Picture->Bitmap->Height; i++)
        {
                pict_line = Image1->Picture->Bitmap->ScanLine[i];
                for (int j= 0 ; j<Image1->Picture->Bitmap->Width; j++)
                {
                        col.R=*(byte*)pict_line;
                        ((byte*)pict_line)++;
                        col.G=*(byte*)pict_line;
                        ((byte*)pict_line)++;
                        col.B=*(byte*)pict_line;
                        ((byte*)pict_line)++;
                        if (col.R> 150 ||col.G> 150 ||col.B> 150 ) col.R=col.B=col.G= 250 ;
                        Y =  0 . 299 *col.R+ 0 . 587 *col.G+ 0 . 114 *col.B;
                        gray[j][i] = Y;
                }
        }
}