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import numba
import numpy as np
@numba.jit(nopython=True)
def rescale_and_lookup(data, scale, offset, lut):
# data should be floating point and 2d
# lut is 1d
vmin, vmax = 0, lut.shape[0] - 1
out = np.empty_like(data, dtype=lut.dtype)
for (x, y) in np.nditer((data, out)):
val = (x - offset) * scale
val = min(max(val, vmin), vmax)
y[...] = lut[int(val)]
return out
@numba.jit(nopython=True)
def rescale_and_clip(data, scale, offset, vmin, vmax):
# vmin and vmax <= 255
out = np.empty_like(data, dtype=np.uint8)
for (x, y) in np.nditer((data, out)):
val = (x - offset) * scale
val = min(max(val, vmin), vmax)
y[...] = val
return out
@numba.jit(nopython=True)
def numba_take(lut, data):
# numba supports only the 1st two arguments of np.take
return np.take(lut, data)
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