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leonarski_fandClaude Opus 5.5 5c28330de6 Azimuthal integration: Q bins equally spaced in log10(Q), or linear by bin count
The Q bins can now be laid out in equal steps of log10(Q) between low and high Q,
dense at low Q and coarse at high Q, as small-angle work needs; such binning is
given by its number of bins. Linear binning takes either its spacing (as before)
or its number of bins, not both. Linear binning by spacing bins every pixel and
reports every bin centre exactly as before.

The Q axis (bin_to_q, written to CBOR and HDF5) holds each bin's centre on its
binning scale: the geometric mean of the edges for log10 bins. The ring background
of the Bragg radial correction and the ice-ring score read the bin centres instead
of assuming a constant spacing. A q rounding onto the far edge of the last bin now
stays in that bin instead of spilling into the next azimuthal row.

rugnux: --azim-q-binning linear|log10 and --azim-q-bins; --mode calibration
refuses log10 bins, as its ring search works in equal Q steps.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HVeDQsU5a8AJUdJPgWevAK
2026-11-10 16:55:48 +01:00

310 lines
17 KiB
C++

// SPDX-FileCopyrightText: 2026 Filip Leonarski, Paul Scherrer Institute <filip.leonarski@psi.ch>
// SPDX-License-Identifier: GPL-3.0-only
#include "BraggIntegrationEngine.h"
#include <algorithm>
#include <cmath>
#include <map>
#include <mutex>
#include <numeric>
#include <string>
#include <tuple>
#include "../../common/JFJochMath.h" // PI (M_PI is not standard, and MSVC does not define it)
#include "../SensorAbsorption.h"
#include "RingBackground.h"
namespace {
// Radial parallax broadening as the coefficient of tan^2(2theta), i.e. Var(z)/pixel^2 [px^2].
// Copied verbatim from ProfileIntegrate2D: a photon converts at a random depth z (exponential,
// attenuation length L, truncated at the sensor thickness), shifting the recorded spot radially by
// z*tan(2theta). L comes from the tabulated NIST attenuation coefficients (SensorAbsorption.h); the
// lambda^3 approximation this used before is within 0.2% for silicon above 10 keV but overstates
// the attenuation length of CdTe by up to a factor of two, and by six above the Cd K edge, which
// made this variance 1.9x too large on 750 um CdTe data.
double parallax_var_px2(const std::string &material, double thickness_um, double lambda_A, double pixel_um) {
if (!(thickness_um > 0.0) || !(pixel_um > 0.0) || !(lambda_A > 0.0))
return 0.0;
const double L = sensor_absorption::AttenuationLength_um(material, lambda_A);
return sensor_absorption::ConversionDepthVariance_um2(L, thickness_um) / (pixel_um * pixel_um);
}
// The radial-offset kernels below are a pure function of these six numbers, and one engine is built
// per worker per pass - 96 of them on a two-pass run - so the table was built 96 times over from the
// same inputs. Build it once and let the rest copy it; it is a few hundred floats. Two workers can
// still race to build the same table, which costs nothing but the second build: the values are
// identical, and emplace keeps whichever arrived first.
struct RadialKernelKey {
float r1_sq, r2, r3;
int n_kern, k_off, k_len;
bool operator<(const RadialKernelKey &o) const {
return std::tie(r1_sq, r2, r3, n_kern, k_off, k_len)
< std::tie(o.r1_sq, o.r2, o.r3, o.n_kern, o.k_off, o.k_len);
}
};
std::mutex radial_kernel_mutex;
std::map<RadialKernelKey, std::vector<float>> radial_kernel_cache;
} // namespace
BraggIntegrationEngine::BraggIntegrationEngine(const DiffractionExperiment &experiment)
: geom(experiment.GetDiffractionGeometry()), modules(experiment.GetModules()),
plane_bounds(modules.PlaneBounds(experiment.GetXPixelsNum(), experiment.GetYPixelsNum())) {
const auto settings = experiment.GetBraggIntegrationSettings();
const auto &det = experiment.GetDetectorSetup();
mode = settings.GetIntegrator();
empirical = mode == IntegratorMode::ProfileEmpirical;
// Same frame as the reflections' predicted_x/predicted_y and the ImagePreprocessorBuffer that
// feeds this engine (MXAnalysisWithoutFPGA sizes that buffer to GetPixelsNum()).
xpixel = experiment.GetXPixelsNum();
ypixel = experiment.GetYPixelsNum();
npixel = experiment.GetPixelsNum();
r1_sq = settings.GetR1() * settings.GetR1();
r2 = settings.GetR2();
r2_sq = r2 * r2;
r3 = settings.GetR3();
r3_sq = r3 * r3;
R = static_cast<int>(std::ceil(r2));
G = 2 * R + 1;
GG = G * G;
// The X-ray bandwidth enters ONE place: it smears a reflection radially by bw_sigma * Rpx, which
// the per-reflection Gaussian carries as part of its radial variance. It is not a mode switch -
// the background estimator and the parallax/capture term below are the same whatever the beam is.
bw_sigma = experiment.GetBandwidthFWHM().value_or(0.0f) / 2.3548f;
const double c_par = parallax_var_px2(det.GetSensorMaterial(), det.GetSensorThickness_um(),
geom.GetWavelength_A(), geom.GetPixelSize_mm() * 1000.0);
c_radial = c_par + bragg_engine::C_CAPTURE;
F_px = geom.GetDetectorDistance_mm() / std::max(1e-6f, geom.GetPixelSize_mm());
beam_x = geom.GetBeamX_pxl();
beam_y = geom.GetBeamY_pxl();
use_ellipse = !empirical;
// Per-reflection signal/background geometry: the ring elongated radially by k_sigma times the
// beam's own radial streak, capped. k_sigma = 0 is the fixed circular stencil, bit for bit, and
// so is any monochromatic beam, where the streak is zero.
stencil.beam_x = beam_x;
stencil.beam_y = beam_y;
stencil.r2 = r2;
stencil.r3 = r3;
stencil.bw_sigma = static_cast<float>(bw_sigma);
stencil.k_sigma = settings.GetStencilKSigma();
stencil.max_grow = bragg_engine::MAX_STENCIL_GROW_OVER_R3 * r3;
// The measured spot footprint (SpotFootprint.h). It moves the ring only where a spot outgrows the
// r1 disk, so a pattern of compact spots integrates exactly as without it.
static_assert(SpotFootprint::MAX_BINS <= BRAGG_FOOTPRINT_MAX_BINS);
stencil.r1 = settings.GetR1();
const auto &fp = settings.GetFootprint();
if (!empirical && !fp.empty()) {
stencil.fp_n = static_cast<int>(fp.sigma_rad.size());
stencil.fp_bin_px = fp.bin_px;
for (int i = 0; i < stencil.fp_n; ++i) {
stencil.fp_sigma_rad[i] = fp.sigma_rad[i];
stencil.fp_sigma_tan[i] = fp.sigma_tan[i];
}
}
// Robust background ring, one estimator or the other (see BraggIntegrationSettings): a high-side
// sigma-clip (rugnux --background-clip, the default) or, when the clip is switched off, a
// symmetric trimmed mean (rugnux --background-trim). The caller owns the choice - the engine no
// longer overrides it for broadband data.
bkg_clip_nsigma = settings.GetBackgroundClipNSigma();
pixel_gain = settings.GetPixelGain();
bkg_trim = bkg_clip_nsigma > 0.0f ? 0.0f : settings.GetBackgroundTrimFraction();
// Overlap treatment. Ownership is decided out to the fit grid's half size, which is where the
// profile fit reads pixels; beyond it a pixel that nobody claims is this reflection's own.
// Excluding the shared pixels needs a profile to renormalise, so it cannot act on a box sum -
// drop it to Off there rather than build an owner map nothing will read.
overlap = settings.GetOverlap();
if (overlap == OverlapMode::Exclude && mode == IntegratorMode::BoxSum)
overlap = OverlapMode::Off;
overlap_min_peak = settings.GetOverlapMinPeak();
keep_overloads = !experiment.IsRotationIndexing();
saturation_limit = static_cast<double>(experiment.GetSaturationLimit());
claim = static_cast<float>(R);
inv_claim = 1.0f / claim;
// Radial-offset kernels for the background curvature correction. A stencil pixel at (dx, dy)
// sits at radial offset dx*cos(phi) + dy*sin(phi) from the reflection, where phi is the
// reflection's azimuth; averaging over phi makes the kernels position-independent, which is
// exact to the extent the stencil is small against the reflection's radius (r3 = 10 px vs
// hundreds). k_diff is the annulus histogram minus the disk histogram, each normalised, so
// dot(k_diff, B) is directly mean_annulus(B) - mean_disk(B).
// Unset = auto: start off, and let the analysis raise it per image where the ice score says the
// background really is radial. An engine nobody drives therefore never applies the correction.
const auto radial = settings.GetBackgroundRadialCorrection();
bkg_radial_auto = !radial.has_value();
bkg_radial = radial.value_or(false);
// The table spans zero growth up to whatever the widest reflection on this detector reaches, one
// kernel per pixel of growth; with nothing elongated a single kernel is all there is, which is
// the layout and the values of every build before the stencil existed. It is built only when the
// correction can ever run - the rows are not cheap, and nothing may read them otherwise:
// bkg_radial is raised after construction only by the auto mode (MXAnalysisWithoutFPGA), which
// requires bkg_radial_auto, and the GPU allocates its curve buffers under the same condition.
// n_kern is the largest row BraggStencilKernelIndex can select, plus one.
r_max = std::hypot(std::max<double>(beam_x - plane_bounds.x0, plane_bounds.x1 - beam_x),
std::max<double>(beam_y - plane_bounds.y0, plane_bounds.y1 - beam_y));
bkg_radial_built = bkg_radial || bkg_radial_auto;
const float grow_max = bkg_radial_built ? BraggStencilMaxGrow_px(static_cast<float>(r_max), stencil)
: 0.0f;
n_kern = static_cast<int>(std::lround(grow_max)) + 1;
// Every row must fit: the last one is built at grow = n_kern - 1, which rounding can put just
// above grow_max.
k_off = static_cast<int>(std::ceil(r3 + std::max<double>(grow_max, n_kern - 1))) + 1;
k_len = 2 * k_off + 1;
const RadialKernelKey kernel_key{r1_sq, r2, r3, n_kern, k_off, k_len};
{
const std::lock_guard lock(radial_kernel_mutex);
if (const auto it = radial_kernel_cache.find(kernel_key); it != radial_kernel_cache.end())
k_diff = it->second;
}
if (k_diff.empty()) {
k_diff.reserve(static_cast<size_t>(n_kern) * k_len);
for (int j = 0; j < n_kern; ++j)
BuildRadialKernel(static_cast<float>(j));
const std::lock_guard lock(radial_kernel_mutex);
radial_kernel_cache.emplace(kernel_key, k_diff);
}
polarization = experiment.GetPolarizationFactor();
}
void BraggIntegrationEngine::BuildRadialKernel(float grow) {
// Histogram the stencil over radial offset, averaged over azimuth so the kernel does not depend
// on where the reflection sits. The average is over the SUB-PIXEL PHASE of the detector grid
// against the radial direction, not over the stencil's own orientation: the stencil is built in
// the reflection's frame at each azimuth, so an elongated one stays aligned with the radius, as
// it is on the detector. k_diff is the annulus histogram minus the disk histogram, each
// normalised, so dot(k_diff, B) is directly mean_annulus(B) - mean_disk(B).
// The signal disk is a circle whatever the ring does, so its histogram is the same for every
// kernel in the table - build it once.
const bool first = hist_disk.empty();
if (first)
hist_disk.assign(k_len, 0.0);
std::vector<double> hist_ann(k_len, 0.0);
constexpr int n_phi = 512;
const int span = static_cast<int>(std::ceil(r3 + grow)) + 1;
const float si = r2 / (r2 + grow), so = r3 / (r3 + grow);
const double q_in = 1.0 - static_cast<double>(si) * si;
const double q_out = 1.0 - static_cast<double>(so) * so;
for (int p = 0; p < n_phi; ++p) {
const double phi = 2.0 * PI * p / n_phi, cp = std::cos(phi), sp = std::sin(phi);
for (int dy = -span; dy <= span; ++dy)
for (int dx = -span; dx <= span; ++dx) {
const double d2 = static_cast<double>(dx) * dx + static_cast<double>(dy) * dy;
const double rad = dx * cp + dy * sp;
const int k = k_off + static_cast<int>(std::lround(rad));
if (k < 0 || k >= k_len)
continue;
const double rad2 = rad * rad;
if (d2 < r1_sq) {
if (first) hist_disk[k] += 1.0;
} else if (d2 - q_in * rad2 >= r2_sq && d2 - q_out * rad2 < r3_sq) {
hist_ann[k] += 1.0;
}
}
}
if (first) sum_disk = std::accumulate(hist_disk.begin(), hist_disk.end(), 0.0);
const double sd = sum_disk;
const double sa = std::accumulate(hist_ann.begin(), hist_ann.end(), 0.0);
for (int k = 0; k < k_len; ++k)
k_diff.push_back(static_cast<float>(hist_ann[k] / sa - hist_disk[k] / sd));
}
void BraggIntegrationEngine::RadialBackgroundFromRings(const std::vector<float> &ring_bkg,
const std::vector<double> &q_centre) {
radial_curve.clear();
const RingBackground rings(ring_bkg, q_centre);
if (rings.empty())
return;
// The same bins as the engines' own curve: one per pixel of distance from the beam, out to the far
// corner.
const int n = static_cast<int>(std::ceil(r_max)) + 2;
const double two_k = 4.0 * PI / geom.GetWavelength_A();
radial_curve.resize(n);
for (int r = 0; r < n; ++r)
radial_curve[r] = static_cast<float>(rings.At(two_k * std::sin(0.5 * std::atan(r / F_px))));
}
std::vector<BraggPanel> BraggIntegrationEngine::Panels(const std::vector<Reflection> &predicted,
size_t npredicted) const {
std::vector<BraggPanel> out(npredicted);
for (size_t i = 0; i < npredicted; ++i) {
const float x = predicted[i].predicted_x, y = predicted[i].predicted_y;
out[i] = MakeBraggPanel(modules, modules.ModuleOfImagePixel(x, y), static_cast<int64_t>(xpixel),
static_cast<int64_t>(ypixel), x, y);
}
return out;
}
std::vector<Reflection> BraggIntegrationEngine::Finalize(const std::vector<Reflection> &predicted,
size_t npredicted,
const std::vector<BraggPanel> &panels,
const std::vector<BraggFitResult> &results,
int64_t image_number) {
// Sized to what is kept, not to what was predicted: this vector is the one every image holds to the
// end of the pass, and a background ring lost to the neighbours drops a reflection here - on a
// dense pattern more than half of them, which a reserve of npredicted would carry as dead capacity.
size_t n_ok = 0;
for (size_t i = 0; i < npredicted; ++i)
n_ok += results[i].ok ? 1 : 0;
std::vector<Reflection> out;
out.reserve(n_ok);
for (size_t i = 0; i < npredicted; ++i) {
const auto &fr = results[i];
if (!fr.ok)
continue;
Reflection refl = predicted[i];
// In photons: the engine measured in ADU, with variances already taken at the gain.
refl.I = fr.I / pixel_gain;
refl.sigma = fr.sigma / pixel_gain;
refl.bkg = fr.bkg / pixel_gain;
refl.var_bkg = fr.var_bkg / (pixel_gain * pixel_gain);
if (fr.has_observed) {
refl.observed_x = fr.observed_x;
refl.observed_y = fr.observed_y;
}
// has_observed is set only for a signal disk every pixel of which was readable.
refl.clipped = !fr.has_observed;
refl.overloaded = fr.overloaded;
// A rotation merge drops the whole rocking event of an overloaded reflection. A still has no
// rocking event: its overloaded observations are the fully recorded ones of the strongest
// reflections, so dropping them leaves those reflections to their partial observations, whose
// partiality correction then sets the merged intensity - and it reads low. Measured on clipped
// CCD stills, the merged low-resolution intensities came out at 0.4-0.6x of the deposited ones.
// So a still keeps the observation as a lower bound: each saturated pixel counted at the
// saturation limit. (A fit to the unsaturated wings was tried and read lower still: the
// profile learned from unsaturated spots does not describe the wings of a clipped one.)
// That takes a pixel AT the limit: an observation overloaded only by pixels unreadable on
// this frame has nothing to count at the limit, and counting those pixels as zero is no
// lower bound of anything - it stays overloaded and is dropped. (A pixel stuck at the limit
// is no clipped spot either; the pre-scan masks it, HotPixelFinder.)
// Counted in ADU like everything else, its own variance at the gain, then in photons.
if (fr.overloaded && keep_overloads && fr.saturated > 0) {
const float I = fr.I + static_cast<float>(fr.saturated * (saturation_limit - fr.bkg));
refl.I = I / pixel_gain;
refl.sigma = std::sqrt(fr.var_bkg + pixel_gain * std::max(I, pixel_gain)) / pixel_gain;
refl.overloaded = false;
++counts.overloads_kept;
}
refl.observed = true;
if (polarization)
refl.prescaling_corr /= geom.CalcAzIntPolarizationCorr(panels[i].plane_x, panels[i].plane_y,
polarization.value());
refl.image_scale_corr = refl.prescaling_corr * refl.qe_corr * refl.flight_corr / refl.partiality;
refl.image_number = static_cast<float>(image_number);
out.push_back(refl);
}
return out;
}