How can I retrieve my raster data from PostGIS database in Django project and calculate my value of the raster at Given location

Question

I have the raster data stored in my database. I want to get that raster data back in my Django and try to find the value at that certain pixel. My code

class dataviewView(views.View):
    def post(self, request):
        data = json.loads(request.body)
        name = data['name']
        lat = data['lat']
        long = data['long']
        point = ogr.Geometry(ogr.wkbPoint)
        point.AddPoint(lat,long)
        if ndvimodel.objects.filter(name = name).exists():
            p1 = ndvimodel.objects.all()
            for raster_data in p1:
                rasterdata = raster_data.rast
                print(type(rasterdata))

But I am unable to get that raster content. How can I solve these issues

Answer 1

Access to raster.bands[0].data() will return numpy array from the first band, then access to raster.geotransform. After yo can use

mx, my = geom.GetX(), geom.GetY() 
px = int((mx - gt[0]) / gt[1]) 
py = int((my - gt[3]) / gt[5]) 
intval = raster.bands[0].data()[px, py]