add support for float32 and float 64

modules/imgcodecs/src/grfmt_gdal.cpp

@@ -135,6 +135,20 @@ int gdal2opencv( const GDALDataType& gdalType, const int& channels ){
             else { return CV_32SC(channels); }
             return -1;
 
+        case GDT_Float32:
+            if( channels == 1 ){ return CV_32FC1; }
+            if( channels == 3 ){ return CV_32FC3; }
+            if( channels == 4 ){ return CV_32FC4; }
+            else { return CV_32FC(channels); }
+            return -1;
+
+        case GDT_Float64:
+            if( channels == 1 ){ return CV_64FC1; }
+            if( channels == 3 ){ return CV_64FC3; }
+            if( channels == 4 ){ return CV_64FC4; }
+            else { return CV_64FC(channels); }
+            return -1;
+
         default:
             std::cout << "Unknown GDAL Data Type" << std::endl;
             std::cout << "Type: " << GDALGetDataTypeName(gdalType) << std::endl;
@@ -207,6 +221,13 @@ double range_cast( const GDALDataType& gdalType,
         return value;
     }
 
+    // float32 -> float32
+    // float64 -> float64
+    if( (gdalType == GDT_Float32 || gdalType == GDT_Float64) &&
+        ( cvDepth == CV_32F     ||  cvDepth == CV_64F   )){
+        return value;
+    }
+
     std::cout << GDALGetDataTypeName( gdalType ) << std::endl;
     std::cout << "warning: unknown range cast requested." << std::endl;
     return (value);