def value(self, view, template=None):
        out = AttrDict()
        for key, typ in self.subtemplates.items():
            out[key] = typ.value(view[key], self)
        return out
Convert string image data to cv2.Mat.
dataset/ETHPy150Open beetbox/beets/beets/util/confit.py/MappingTemplate.value--crossover with--dataset/ETHPy150Open GoogleCloudPlatform/appengine-opencv-sudoku-python/sudoku_image_parser.py/SudokuImageParser._create_image_from_data