Merry Christmas

camera.md

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+# Camera
+Most models of the RPi have a camera port but pay attention as the RPi Zero has a smaller port and needs a smaller ribbon cable.
+There are two types of camera modules:
+- standard: take pictures in normal light
+- NoIR: without infrared filter, you can take pictures in the dark with an infrared light source
+
+## Connect the module
+1. look for the camera module port on your RPi
+2. pull up the edges of the ports plastic clip
+3. insert the camera ribbon cable and make sure the contacts face the ribbon cable connectors
+4. push down the plastic clip into place
+
+## Activate your camera
+Power up your RPi and start the config tool with `sudo raspi-config`. Scroll down to "enable camera" and set it to "Yes". Now restart your RPi to load all librarys. 
+
+## Taking pictures from cli
+Raspbian has it's own librarys to interact with the camera. To take pictures you can use the command `raspistill`. Here is a little list of what is possible:
+- Take a jpg picture (standard): `raspistill -o image.jpg`
+- Take a png picture (or bmp/gif): `raspistill -o image.png -e png`
+- Take a picture without preview: `raspistill -o image.jpg -n`
+- Wait 3000ms to take the picture: `raspistill -o image.jpg -t 3000`
+- set the width and height of the picture: `raspistill -o image.jpg -w 640 -h 480`
+- set the quality of the picture (from 0 to 100%): `raspistill -o image.jpg -q 20`
+- take a series of  pictures all 5 seconds for a whole hour (3600000 seconds): `raspistill -o image_%04d.jpg -tl 5000 -t 3600000` (later you can stick it together with ffmpeg to get a movie)
+
+## Taking videos from cli
+Next to pictures you can take videos
+- take a video for 5 seconds: `raspivid -o video.h264 -t 50000` (to never end set t to 0)
+- set width and height: `raspivid -o video.h264 -t 50000 -w 1280 -h 720`
+- set the bitrate: `raspivid -o video.h264 -t 50000 -b 3500000`
+- set the framerate: `raspivid -o video.h264 -t 50000 -f 10`
+- send the video stream to sdtout: `raspivid -t 50000 -o - `
+
+To convert videos from H264 to mp4 you can use gpac:
+```bash
+sudo apt-get install gpac
+MP4Box -fps 30 -add video.h264 video.mp4
+```
+
+## Control the camera with python
+You can control your camera using python libraries (preinstalled on Raspbian). 
+
+Open an editor and paste the following, save it like `camera.py`.
+```python
+from picamera import PiCamera
+from time import sleep
+
+camera = PiCamera()
+
+camera.start_preview()
+sleep(5)
+camera.stop_preview()
+```
+The camera should be shown 5 seconds and then close.
+
+There are several functions/filters you can use:
+- Rotate (in degree): `camera.rotation = 180`
+- Make the camera preview see-through by setting an alpha level: `camera.start_preview(alpha=200)`
+- Take a picture (it’s important to sleep for at least two seconds before capturing an image because this gives the camera’s sensor time to sense the light levels)
+    ```python
+    camera.start_preview()
+    sleep(5)
+    camera.capture('/home/pi/Desktop/image.jpg')
+    camera.stop_preview()
+    ```
+- record a video: 
+    ```python
+    camera.start_recording('/home/pi/Desktop/video.h264')
+    sleep(5)
+    camera.stop_recording()
+    ```
+- change the resolution: `camera.resolution = (2592, 1944)` 
+  - maximum resolution is 2592x1944 for still photos, 
+  - maximum resolution is 1920x1080 for video recording, 
+  - minimum resolution is 64x64
+- change the framerate: `camera.framerate = 15`
+  - 0 is minimum 
+  - 15 is maximum
+- add text to your image: `camera.annotate_text = "Hello world!"`
+
+# Source and more
+[RaspberryPi.com](https://www.raspberrypi.com/documentation/accessories/camera.html)