subtract_corner_background
- laserbeamsize.background.subtract_corner_background(image, corner_fraction=0.035, nT=3, iso_noise=True)[source]
Return image with background subtracted.
The mean and standard deviation are estimated using the pixels from the rectangles in the four corners. The default size of these rectangles is 0.035 or 3.5% of the full image size.
The new image will have a constant with the corner mean subtracted.
ISO 11146-3 recommends values from 2-5% for corner_fraction.
ISO 11146-3 recommends from 2-4 for nT.
If iso_noise is False, then after subtracting the mean of the corners, pixels values < nT * stdev will be set to zero.
If iso_noise is True, then no zeroing background is done.
- Parameters:
image – the image to work with
corner_fraction – the fractional size of corner rectangles
nT – how many standard deviations to subtract
- Returns:
image – 2D array with background subtracted