More documention about gaze analysis pipeline.

1 files changed, 56 insertions, 0 deletions

diff --git a/docs/user_guide/gaze_analysis_pipeline/background.md b/docs/user_guide/gaze_analysis_pipeline/background.md
new file mode 100644
index 0000000..420dbdf
--- /dev/null
+++ b/docs/user_guide/gaze_analysis_pipeline/background.md
@@ -0,0 +1,56 @@
+Add Background
+==============
+
+Background is an optional [ArFrame](../../argaze.md/#argaze.ArFeatures.ArFrame) attribute to display any image.
+
+![Background](../../img/ar_frame_background.png)
+
+## Load and display ArFrame background
+
+[ArFrame.background](../../argaze.md/#argaze.ArFeatures.ArFrame.background) can be enabled thanks to a dedicated JSON entry.
+
+Here is the JSON ArFrame configuration file example where a background picture is loaded and displayed:
+
+```json
+{
+    "name": "My FullHD screen",
+    "size": [1920, 1080],
+    ...
+    "background": "./joconde.png",
+    ...
+    "image_parameters": {
+        ...
+        "background_weight": 1
+    }
+}
+```
+
+Now, let's understand the meaning of each JSON entry.
+
+### Background
+
+The path to an image file on disk.
+
+### Background weight
+
+The weight of background overlay in [ArFrame.image](../../argaze.md/#argaze.ArFeatures.ArFrame.image) between 0 and 1.
+
+## Edit ArFrame background
+
+It is also possible to set background image and display it from script:
+
+```python
+import numpy
+
+# Assuming an ArFrame is loaded
+...
+
+# Set ArFrame background as gray
+ar_frame.background = numpy.full((ar_frame.size[1], ar_frame.size[0], 3), 127).astype(numpy.uint8)
+
+# Get ArFrame image with background and any other options
+ar_frame_image = ar_frame.image(background_weight = 1, ...)
+
+# Do something with ArFrame image
+...
+```