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dict keywords:
seg : array
ofint
- 2-d segment index (beginning from 0), e.g. in CSPAD consisting of 32 segments this index should be in the range from 0 to 31row : array
ofint
- row (beginning from 0) of the central pixel with maximal intensity in the square region defined byrank
col : array
ofint
- column (beginning from 0) of the central pixel with maximal intensity in the square region defined byrank
npix : array
ofint
- number of pixels accounted in the peakamp_max : array
offloat
- maximal intensity among peak pixelsamp_total : array
offloat
- total intensity of pixels accounted in the peakrow_cgmean : array
offloat
- row "center of gravity" row coordinate evaluated for pixels accounted in the peak using their intensities as weightscol_cgmean : array
offloat
- column "center of gravity" coordinate column coordinate evaluated for pixels accounted in the peak using their intensities as weightsraw_cgrms : array
offloat
- row "center of gravity" coordinate row coordinate rmscol_cgrms : array
offloat
- column "center of gravity" coordinate column coordinate rmsbase : array
offloat
- per pixel base level mean estimated for pixels in the ring region (parameters
) around peak centerbase_r
, base_dr
noise : array
offloat
- per pixel base level rms estimated for pixels in the ring region (parameters
) around peak centerbase_r
, base_dr
son : array
offloat
- signal over noise ratio estimated asamp_total
/(noise * sqrt(
npix
))peak : list
ofpeak
objects
peak attributes:pixrow : array
ofint
- row index for pixels accounted in the peakpixcol : array
ofint
- column index for pixels accounted in the peak
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- peaks_two_thr - is a two-threshold peak-finding algorithm searching for groups of connected pixels with intensity above
thr
_low
in the square region restricted by the parameterrank
around central pixel with intensity exceedingthr_high
in the region restricted by the radial parameterrank
. In the loop over all pixels each pixel with intensity grater or equalthr_high
is considered as a peak candidate. For each candidate recursive algorithm is launched and searches for a group of connected pixels with intensity grater or equalthr
_low
in the square region with dimensions2*rank+1
pixel in rows and columns. Pixels of the group are marked as busy on 2-d map and are not used for in other groups. Central pixel of the peak candidate should have maximal intensity in the group of connected pixels, otherwise recursion is terminated and all group pixels released for further search. Two neighbor pixels with intensity abovethr
_low
having common boarder are assumed connected. Two pixels having a single common vertex are assumed disconnected. Base level mean,bkgd
base
, and , rms,noise
values , values are evaluated for pixels in the ring with internal radiusbase_r
and widthbase_dr
around central pixel. Pixels with intensity abovethr
_low
are excluded from evaluation of the base level parameters.
- peaks_adapt_thr - searches is an adaptive-threshold peak-finding algorithm searching peak candidates as group of connected pixels with intensity above dynamically estimated evaluated threshold around local intensity maximums of specified
rank
. Maps of local maximums and minimums of specifiedrank
are generated fordata
array. Parameterrank
defines a square region with dimensions2*rank+1
pixels in rows and columns around center pixel. Each local maximum is of specifiedrank
is considered as a peak candidate. Its base level mean,bkgd
base
, and rms,noise
, values are evaluated using surrounding pixels in the ring with internal radiusbase_r
and widthbase_dr
. Pixels marked as local maximums and minimums (for symmetry) of specifiedrank
in rows and columns are excluded in evaluation of the base level parameters.NOTE:
due to excluded extremes the base level rms is under-estimated in this algorithm, so, set parameternsigm
wisely.Then, for each peak candidate local adaptive-threshold parameterthr=
(no exclusion forbkgd
base
+nsigm*noisensigm=0
) is is used. Recursive algorithm searches for the group of connected pixels with intensity above local thresholdthr
in therank
-restricted region.
NOTE:
due to excluded extremes the base level rms is under-estimated in this algorithm, so, set parameter nsigm
wisely.
Other stages of all algorithms are about the same.
- returned values of
amp_max
andamp_total
are base level corrected by subtractingbkgd
andbkgd
base
andbase
*
, respectively, if do_base_sub=True.npix
- signal over noise
son
is evaluated asamp_total
/(noise * sqrt(
,npix
)) - output list of peaks is generated from the list of seed peaks complying with selection parameters
npix_min, npix_max, amax_thr, atot_thr, son_min
.
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