How do you extract the raw image from a JPEG taken by the v2 camera?

Question

I'm very new to working with the Raspberry Pi. For a project, I must have the raw images taken by the camera instead of the processed JPEGs. If I take a raw image using:

raspistill -r -o test.jpg

then how do I extract the raw image from test.jpg or process test.jpg to give me a readable raw file (.raw) back? I've seen many solutions online, but either they haven't worked for me or I don't know how to use them.

Answer 1

In Python you can use https://github.com/OsmoSystems/picamraw/ to extract the raw Bayer data or a rudimentary demosaiced RGB image. The result is a numpy array that you can use with a variety of other python tools. This basic example should display the raw image:

First, install matplotlib and picamraw with pip install matplotlib picamraw.

Then, import the code, grab the bayer array, convert it to RGB and display it:

from matplotlib import pyplot as plt
import picamraw

raw_bayer = picamraw.PiRawBayer(
    filepath='path/to/image.jpeg',
    camera_version=picamraw.PiCameraVersion.V2,
)

plt.imshow(raw_bayer.to_rgb())

Full disclosure: my team just released that package. Let us know if you have any questions!