From 625efeb8ebc75a9167c8abc9f0e7afe10b120be5 Mon Sep 17 00:00:00 2001
From: Kai Chen <chenkaidev@gmail.com>
Date: Sat, 23 Nov 2019 16:39:07 +0800
Subject: [PATCH] update installation guide (#1701)

---
 docs/INSTALL.md | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/docs/INSTALL.md b/docs/INSTALL.md
index 8f4fb76..b88380b 100644
--- a/docs/INSTALL.md
+++ b/docs/INSTALL.md
@@ -42,8 +42,8 @@ cd mmdetection
 d. Install mmdetection (other dependencies will be installed automatically).
 
 ```shell
-python setup.py develop
-# or "pip install -v -e ."
+pip install mmcv
+python setup.py develop  # or "pip install -v -e ."
 ```
 
 Note:
@@ -53,6 +53,9 @@ It is recommended that you run step d each time you pull some updates from githu
 
 2. Following the above instructions, mmdetection is installed on `dev` mode, any local modifications made to the code will take effect without the need to reinstall it (unless you submit some commits and want to update the version number).
 
+3. If you would like to use `opencv-python-headless` instead of `opencv-python`,
+you can install it before installing MMCV.
+
 ### Another option: Docker Image
 
 We provide a [Dockerfile](../docker/Dockerfile) to build an image.
-- 
GitLab