[gdal-dev] read whole elevation data from geotif to vector[x][y]

[Mateusz Łoskot]

On 17 June 2014 20:56, Robert Grah <smilingmolecule at web.de> wrote:
>
> I try to read the whole elevation data from a band of a GeoTiff image into a c++ 2d vector so that I can read the values like vector[x][y].
> [...]
> Is there an easy way to get the values ordered like the pixels of an image?
> From left to right and top to bottom? I think i am overlooking something...

I think, your image is read correctly into vector of vectors,
but you are mismatching x and y indices while accessing individual pixels.

Compare your technique of accessing with this simple example:

// image 3x4
std::vector<std::vector<int>> v =
{
    { 1, 2, 3, 4 },// scanline 0
    { 5, 6, 7, 8 },// scanline 1
    { 9,10,11,12 } // scanline 2
};

std::size_t y(1), x(2);
int pixel = v[y][x]; // value 7

Notice, it is v[y][x]. no v[x][y].

Best regards,
-- 
Mateusz  Łoskot, http://mateusz.loskot.net