GONet Cameras
A GONet camera is an imaging unit built around a Raspberry Pi camera stack and
a Sony IMX477 image sensor. In the current configuration, GONet uses the
Raspberry Pi HQ Camera module and captures images through the legacy
picamera/MMAL pipeline.
For GONet Wizard, the most important practical point is that these cameras do not only produce ordinary JPEG images. When acquisition is configured with raw capture enabled, the JPEG file also contains raw Bayer sensor data. That raw component preserves physically meaningful pixel values that are better suited to quantitative work than the processed 8-bit JPEG preview.
Hardware overview
The current GONet hardware configuration uses:
Raspberry Pi HQ Camera module.
Sony IMX477 back-illuminated CMOS image sensor.
Native full-frame resolution of 4056 x 3040 pixels.
1.55 micrometer pixels.
Rolling shutter readout.
Native 12-bit ADC output.
Raw Bayer acquisition when enabled by the capture pipeline.
The raw sensor values span the physical ADC range from approximately 0 to 4095. For saturation analysis, this matters: a raw pixel value near 4095 corresponds to the meaningful saturation limit of the acquisition, whereas the JPEG image is an 8-bit, ISP-processed representation intended primarily for display.
Acquisition pipeline
GONet images are captured with the legacy Raspberry Pi camera stack, using
picamera with the camera configured in sensor mode 3. Conceptually, the
capture pipeline produces two related products inside the same image file:
an ISP-processed JPEG image, convenient for quick viewing;
a packed 12-bit raw Bayer block, useful for quantitative analysis.
GONet Wizard focuses on recovering and working with the scientifically useful parts of that file while still making the convenient display image available for inspection and visualization.
Current sensor mode
The current GONet configuration uses sensor_mode = 3. In the legacy IMX477
camera stack, this mode provides:
full-resolution readout at 4056 x 3040 pixels;
full sensor field of view;
true 12-bit raw Bayer acquisition;
no binning;
maximum dynamic range for still-image acquisition.
This is the mode assumed by the GONet parsing utilities in the package. It is also why the raw data path is central to GONet Wizard: the raw values preserve the full 12-bit dynamic range of the sensor.
Why raw data matters
The JPEG image is useful for visual inspection, but it has already passed through the camera image signal processor. During that processing, the data are converted to 8-bit channels and may be affected by color processing, tone mapping, compression, and other display-oriented transformations.
The raw Bayer data are different. They retain the sensor measurements before that display-oriented processing. For tasks such as saturation checks, channel statistics, or repeatable photometric-style measurements, the raw data are the preferred input.
GONet Wizard therefore treats a GONet image as more than a picture. It treats it as an observational data product containing image arrays, channels, and metadata.