docs: boolean isScaleSpaceExtremum(int c_x, int c_y, float value, float signAdj) {
  		if( c_x <= 1 || c_y <= 1 || c_x >= dogLower.width-1 || c_y >= dogLower.height-1)
  			return false;
  
  		float v;
  
  		value *= signAdj;
  
  		for( int y = -1; y <= 1; y++ ) {
  			for( int x = -1; x <= 1; x++ ) {
  			    v = dogLower.unsafe_get(c_x+x,c_y+y);
  				if( v*signAdj >= value )
  					return false;
  				v = dogUpper.unsafe_get(c_x+x,c_y+y);
  				if( v*signAdj >= value )
  					return false;
  			}
  		}
  
  		return true;
  	}