[Liblas-devel] libLAS 1.6.1 - Can't read color in Point Format 2

[Howard Butler]

On Nov 8, 2011, at 3:15 PM, Ryan W. Frenz wrote:

> It seems I am unable to read RGB color from points in point format 2.  Using the code snippets below, I write 10 points to a LAS file, with RGB color, and then read it back.  I can read back the coordinates properly but not the color (I get RGB=0,0,0 for all points).  Anything jump out that I'm doing wrong?  Could someone point me to some sample data in point format 2 that I could use for testing?
> 
> Notes:
> - This same code works properly using Point Format 0 and Set/GetIntensity instead of Color.
> - I am performing this test using libLAS 1.6.1 compiled for Windows (same results in 32 and 64 bit).
> 
> Thanks in advance,
> Ryan
> 
> void write(const std::string& filename) {
>    std::ofstream out(filename, std::ios::binary);
>    liblas::Header h;
>    h.SetDataFormatId(liblas::ePointFormat2);
>    h.SetPointRecordsCount(10);
>    h.SetPointRecordsByReturnCount(1, 10);
>    h.SetScale(0.001, 0.001, 0.001);
>    h.SetOffset(0,0,0);
> 
>    liblas::Writer w(out, h);
>    for (double i = 0; i <= 1.0; i+=0.1) {
>      liblas::Point p;
>      p.SetX(i);  p.SetY(i); p.SetZ(i);
>      liblas::Color c;
>      c.SetRed(static_cast<liblas::Color::value_type>(std::numeric_limits<liblas::Color::value_type>::max() * i));
>      c.SetGreen(static_cast<liblas::Color::value_type>(std::numeric_limits<liblas::Color::value_type>::max() * i));
>      c.SetBlue(static_cast<liblas::Color::value_type>(std::numeric_limits<liblas::Color::value_type>::max() * i));
>      p.SetColor(c);
>      w.WritePoint(p);
>    }
>    out.close();
> }
> 
> void read(const std::string& filename) {
>    std::ifstream in(filename, std::ios::binary);
>    liblas::Reader reader(in);
>    int ct = 0;
>    while ((ct < 10) && reader.ReadNextPoint()) {
>      const liblas::Point& p = reader.GetPoint();
>      std::cerr << p.GetX() << ", " << p.GetY() << ", " << p.GetZ() << ", " << p.GetColor().GetRed() << ", " << p.GetColor().GetGreen() << ", " << p.GetColor().GetBlue() << "\n";
>      ++ct;
>    }
>    in.close();
> }

Ryan,

Please pull the latest from github if you can.  A number of issues have been fixed, and I think the issue you're running into was http://trac.liblas.org/ticket/224

https://github.com/liblas/liblas

Howard