Avoid overflow in ljpeg_start().
void CLASS hat_transform (float *temp, float *base, int st, int size, int sc)
{
  int i;
  for (i=0; i < sc; i++)
    temp[i] = 2*base[st*i] + base[st*(sc-i)] + base[st*(i+sc)];
  for (; i+sc < size; i++)
    temp[i] = 2*base[st*i] + base[st*(i-sc)] + base[st*(i+sc)];
  for (; i < size; i++)
    temp[i] = 2*base[st*i] + base[st*(i-sc)] + base[st*(2*size-2-(i+sc))];
}

void CLASS hat_transform (float *temp, float *base, int st, int size, int sc)
{
  int i;
  for (i=0; i < sc; i++)
    temp[i] = 2*base[st*i] + base[st*(sc-i)] + base[st*(i+sc)];
  for (; i+sc < size; i++)
    temp[i] = 2*base[st*i] + base[st*(i-sc)] + base[st*(i+sc)];
  for (; i < size; i++)
    temp[i] = 2*base[st*i] + base[st*(i-sc)] + base[st*(2*size-2-(i+sc))];
}
