void VFilter( const TwoDArray<unsigned char>& pic_data, TwoDArray<unsigned char>& out_data, const OneDArray<int>& filter, const int bits )
{
const int offset = (1<<(bits-1));
int sum, j, jout;
// Do the first bit
for (j=0, jout=0; j<filter.Last(); j+=2, jout++)
{
for (int i=0; i<pic_data.LengthX(); ++i)
{
sum = offset;
for (int k=filter.Last(); k>=filter.First(); --k)
sum += filter[k]*static_cast<int>( pic_data[std::max(j-k,0)][i] );
sum >>= bits;
sum = std::min( 255, std::max( 0, sum) );
out_data[jout][i] = static_cast<unsigned char>( sum );
}// i
}// j
// Do the middle bit
for (; j<=pic_data.LastY()+filter.First(); j+=2, jout++)
{
for (int i=0; i<pic_data.LengthX(); ++i)
{
sum = offset;
for (int k=filter.Last(); k>=filter.First(); --k)
sum += filter[k]*static_cast<int>( pic_data[j-k][i] );
sum >>= bits;
sum = std::min( 255, std::max( 0, sum) );
out_data[jout][i] = static_cast<unsigned char>( sum );
}// i
}// j
// Do the last bit
for (; j<pic_data.LengthY(); j+=2, jout++)
{
for (int i=0; i<pic_data.LengthX(); ++i)
{
sum = offset;
for (int k=filter.Last(); k>=filter.First(); --k)
sum += filter[k]*static_cast<int>( pic_data[std::min(j-k,pic_data.LastY())][i] );
sum >>= bits;
sum = std::min( 255, std::max( 0, sum) );
out_data[jout][i] = static_cast<unsigned char>( sum );
}// i
}// j
}
void HFilter( const TwoDArray<unsigned char>& pic_data, TwoDArray<unsigned char>& out_data, const OneDArray<int>& filter, const int bits )
{
unsigned char* line_data;
const int offset = (1<<(bits-1));
int sum;
int i, iout;
for (int j=0; j<pic_data.LengthY(); ++j)
{
line_data = out_data[j];
// Do the first bit
for (i=0, iout=0; i<filter.Last(); i+=2, iout++)
{
sum = offset;
for (int k=filter.Last(); k>=filter.First(); --k)
sum += filter[k]*static_cast<int>(pic_data[j][std::max(i-k,0)]);
sum >>= bits;
sum = std::min( 255, std::max( 0, sum) );
line_data[iout] = static_cast<unsigned char>( sum );
}// i
// Do the middle bit
for (; i<=pic_data.LastX()+filter.First(); i+=2, iout++)
{
sum = offset;
for (int k=filter.Last(); k>=filter.First(); --k)
sum += filter[k]*static_cast<int>( pic_data[j][i-k] );
sum >>= bits;
sum = std::min( 255, std::max( 0, sum) );
line_data[iout] = static_cast<unsigned char>( sum );
}// i
// Do the last bit
for (; i<pic_data.LengthX(); i+=2, iout++)
{
sum = offset;
for (int k=filter.Last(); k>=filter.First(); --k)
sum += filter[k]*static_cast<int>( pic_data[j][std::min(i-k,pic_data.LastX())] );
sum >>= bits;
sum = std::min( 255, std::max( 0, sum) );
line_data[iout] = static_cast<unsigned char>( sum );
}// i
}// j
}