OCR Chinese CHOOSE_PRE_INSTALLED_MODEL_KEY ENABLE_CUSTOM_SETTINGS_KEY MODEL_PATH_KEY LABEL_PATH_KEY IMAGE_PATH_KEY CPU_THREAD_NUM_KEY CPU_POWER_MODE_KEY INPUT_COLOR_FORMAT_KEY INPUT_SHAPE_KEY INPUT_MEAN_KEY INPUT_STD_KEY SCORE_THRESHOLD_KEY models/ocr_v2_for_cpu labels/ppocr_keys_v1.txt images/0.jpg 4 LITE_POWER_HIGH BGR 1,3,960 0.485, 0.456, 0.406 0.229,0.224,0.225 0.1