Noise

Module for describing different kinds of noise.

abtem.noise.add_scan_noise(measurement, dwell_time, flyback_time, max_frequency, rms_power, num_components=200)[source]

Add scan noise to a measurement.

Parameters
  • measurement (Measurement object or 2d array) – The measurement to add noise to.

  • dwell_time (float) – Dwell time on a single pixel in s.

  • flyback_time (float) – Flyback time for the scanning probe at the end of each scan line in s.

  • max_frequency (float) – Maximum noise frequency in 1 / s.

  • rms_power (float) – Root-mean-square power of the distortion in unit of percent.

  • num_components (int, optional) – Number of frequency components. More components will be more ‘white’ but will take longer.

Returns

measurement – The noisy measurement.

Return type

Measurement object

abtem.noise.poisson_noise(measurement, dose, pixel_area=None, negative_values='clip')[source]

Add Poisson noise to a measurment.

Parameters
  • measurement (Measurement object) – The measurement to add noise to.

  • dose (float) – The irradiation dose in electrons per Å^2.

  • pixel_area (float, optional) – Pixel area in Å^2. If not provided this will be calculated from the calibraions when possible.

Returns

measurement – The noisy measurement.

Return type

Measurement object