void CResizableImage::HorizontalFilter(unsigned int dst_width, unsigned int dst_height)
{
if (dst_width == myWidth)
{
// No scaling required, just copy
memcpy (myResizedImage, myRGBArray, sizeof(RGBQUAD) * myWidth * myHeight);
}
myWeightsTable = new CWeightsTable(myFilter, dst_width, myWidth);
for (UINT u = 0; u < dst_height; u++)
{
// scale each row
ScaleRow (dst_width, dst_width, u); // Scale each row
}
delete myWeightsTable;
}
// Reduces all elements in a column except the diagonal element
// Returns 0 on success, 1 if the column cannot be reduced
int Matrix::ReduceColumn(int column, Matrix &inverse)
{
// loop variable for working down column
int row, pivot = column;
// find the first non-zero element in the column
// that is not above the diagonal
for (row = pivot; row < 4; row++)
if (fabs(Element(row, pivot)) > ERROR_TOLERANCE)
break;
// if we didn't find one, return an error code
if (row == 4) return 1;
// if we did, but it wasn't on the diagonal, swap with the pivot row
// this makes sure we never get divide by zero errors
if (row != pivot)
{
SwapRows(pivot, row);
inverse.SwapRows(pivot, row);
}
// now scale the pivot row so the pivot element is one
float scaleFactor = 1.0 / Element(pivot, pivot);
ScaleRow(pivot, scaleFactor);
inverse.ScaleRow(pivot, scaleFactor);
// for each row
for (row = 0; row < 4; row++)
{
// skip the row we're pivoting on
if (row == column) continue;
scaleFactor = -Element(row, pivot);
AddRows(row, scaleFactor, pivot);
inverse.AddRows(row, scaleFactor, pivot);
}
// and we're done
return 0;
}
