Re: reading jpegs faster

[John W. Eaton]

On 22-Jan-2010, David Grundberg wrote:

| Okay. Now I got it down to 1.3 seconds. That's 130% compared to the 
| jpgread performance, instead of the previous 900%. Needs polish, but it 
| works.

Thanks for looking at this problem.

| +        P *vec = reinterpret_cast<P *> (im.fortran_vec ());

I don't think this cast is needed, given that P appears to always be
the same as the element type of IM.  So you could use the element_type
typedef from the class T and eliminate the template parameter P:

  template <class T, unsigned int D>
  octave_value_list
  read_images (const std::vector<Magick::Image>& imvec,
               const Array<int>& frameidx, unsigned int depth)
  {
    octave_value_list retval (3, Matrix ());

    T im;

    typedef typename T::element_type P;

      ...

          P *vec = im.fortran_vec ();

         ...

          case 1:
            output = read_images<boolNDArray, 1> (imvec, frameidx, depth);
            break;

          ...

jwe