Initial commit: DCNv4 custom op mirror setup

- Add enhanced README with project structure and quick start guide
- Initialize repository with DCNv4 CUDA extension (PyTorch module)
- Include classification, detection, and segmentation subdirectories
- Reference upstream OpenGVLab DCNv4 implementation

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

classification/logger.py

@@ -0,0 +1,44 @@
+# --------------------------------------------------------
+# DCNv4
+# Copyright (c) 2024 OpenGVLab
+# Licensed under The MIT License [see LICENSE for details]
+# --------------------------------------------------------
+
+import os
+import sys
+import logging
+import functools
+from termcolor import colored
+
+
+@functools.lru_cache()
+def create_logger(output_dir, dist_rank=0, name=''):
+    # create logger
+    logger = logging.getLogger(name)
+    logger.setLevel(logging.DEBUG)
+    logger.propagate = False
+
+    # create formatter
+    fmt = '[%(asctime)s %(name)s] (%(filename)s %(lineno)d): %(levelname)s %(message)s'
+    color_fmt = colored('[%(asctime)s %(name)s]', 'green') + \
+        colored('(%(filename)s %(lineno)d)', 'yellow') + \
+        ': %(levelname)s %(message)s'
+
+    # create console handlers for master process
+    if dist_rank == 0:
+        console_handler = logging.StreamHandler(sys.stdout)
+        console_handler.setLevel(logging.DEBUG)
+        console_handler.setFormatter(
+            logging.Formatter(fmt=color_fmt, datefmt='%Y-%m-%d %H:%M:%S'))
+        logger.addHandler(console_handler)
+
+    # create file handlers
+    file_handler = logging.FileHandler(os.path.join(
+        output_dir, f'log_rank{dist_rank}.txt'),
+                                       mode='a')
+    file_handler.setLevel(logging.DEBUG)
+    file_handler.setFormatter(
+        logging.Formatter(fmt=fmt, datefmt='%Y-%m-%d %H:%M:%S'))
+    logger.addHandler(file_handler)
+
+    return logger