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Gamma Correction

This tutorial demonstrates how to capture a 2D image with a configurable gamma correction.

First, we connect to the camera.

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camera = app.connect_camera()

Then we get the gamma as command line argument from user.

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user_options = _options()
print(f"Capturing with gamma correction: {user_options.gamma}")

We then capture the image with no gamma correction (gamma = 1.0) and with given gamma correction (in this case, gamma = 0.6).

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bgr_original = _capture_bgr_image(camera, 1.0)
bgr_adjusted = _capture_bgr_image(camera, user_options.gamma)

The complete implementation of the function to capture a color image is given below.

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def _capture_bgr_image(camera, gamma):
    """Capture and extract 2D image, then convert from RGBA and return BGR.

    Args:
        camera: Zivid Camera handle
        gamma: Gamma correction value

    Returns:
        BGR image (HxWx3 darray)

    """
    print("Configuring Settings")
    settings_2d = zivid.Settings2D(
        acquisitions=[zivid.Settings2D.Acquisition()],
    )
    settings_2d.processing.color.gamma = gamma

    print("Capturing 2D frame")
    with camera.capture(settings_2d) as frame_2d:
        image = frame_2d.image_rgba()
        rgba = image.copy_data()
        bgr = cv2.cvtColor(rgba, cv2.COLOR_RGBA2BGR)
        return bgr

Lastly, we display both images.

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width = (int)(bgr_original.shape[1] / 2)
combined_image = np.hstack([bgr_original[:, :width], bgr_adjusted[:, -width:]])
cv2.imshow("Original on left, adjusted on right", combined_image)
print("Press any key to continue")
cv2.waitKey(0)