{ "input_shape": [ 50, 50, 1 ], "pixel_convention": "digit stroke = 0, background = 1 (inverted binary, see clean_and_resize_optimized)", "normalization": "binary 0/1 via Otsu threshold + bitwise_not, then /255", "num_classes": 10, "class_mapping": "index == digit value (0-9)" }