Updated README

docker/README.md

@@ -1,6 +1,57 @@
 # Instructions
 
-Build all docker images, in order:
+# Images on Docker Hub
+
+There are 4 images available on https://hub.docker.com/orgs/borglab/repositories:
+
+- `borglab/ubuntu-boost-tbb`: 18.06 Linux (nicknamed `bionic`) base image, with Boost and TBB installed.
+- `borglab/ubuntu-gtsam`: GTSAM Release version installed in `/usr/local`.
+- `borglab/ubuntu-gtsam-python`: installed GTSAM with python wrapper.
+- `borglab/ubuntu-gtsam-python-vnc`: image with GTSAM+python wrapper that will run a VNC server to connect to.
+
+# Using the images
+
+## Just GTSAM
+
+To start the Docker image, execute
+```bash
+docker run -it borglab/ubuntu-gtsam:bionic 
+```
+after you will find yourself in a bash shell, in the directory `/usr/src/gtsam/build`.
+## GTSAM with Python wrapper
+
+To use GTSAM via the python wrapper, similarly execute
+```bash
+docker run -it borglab/ubuntu-gtsam-python:bionic 
+```
+and then launch `python3`:
+```bash
+python3
+>>> import gtsam
+>>> gtsam.Pose2(1,2,3)
+(1, 2, 3)
+```
+
+## GTSAM with Python wrapper and VNC
+
+First, start the docker image, which will run a VNC server on port 5900:
+```bash
+docker run -p 5900:5900 borglab/ubuntu-gtsam-python-vnc:bionic
+```
+
+Then open a remote VNC X client, for example:
+
+### Linux
+```bash
+sudo apt-get install tigervnc-viewer
+xtigervncviewer :5900
+```
+### Mac
+In the finder, in the Go menu, select "Connect to Server...", enter `vnc://127.0.0.1`, and then press "Connect". When prompted for a password, leave blank and press "Sign In".
+
+# Re-building the images locally
+
+To build all docker images, in order:
 
 ```bash
 (cd ubuntu-boost-tbb && ./build.sh)
@@ -9,13 +60,4 @@ Build all docker images, in order:
 (cd ubuntu-gtsam-python-vnc && ./build.sh)
 ```
 
-Then launch with: 
+Note: building GTSAM can take a lot of memory because of the heavy templating. It is advisable to give Docker enough resources, e.g., 8GB, to avoid OOM errors while compiling.
-
-    docker run -p 5900:5900 dellaert/ubuntu-gtsam-python-vnc:bionic
-
-Then open a remote VNC X client, for example:
-
-    sudo apt-get install tigervnc-viewer
-    xtigervncviewer :5900
-
-