fix

rfg_adc_plotter/cli.py

@@ -37,6 +37,15 @@ def build_parser() -> argparse.ArgumentParser:
             "в водопаде спектров (0 — отключить)"
         ),
     )
+    parser.add_argument(
+        "--bscan-db-range",
+        dest="bscan_db_range",
+        default="80,150",
+        help=(
+            "Фиксированный диапазон цветовой шкалы B-scan в дБ (min,max). "
+            "Напр. 80,150. Применяется к обычному виду (без вычитания фона)."
+        ),
+    )
     parser.add_argument("--title", default="ADC Sweeps", help="Заголовок окна")
     parser.add_argument(
         "--fancy",

rfg_adc_plotter/gui/pyqtgraph_backend.py

@@ -31,7 +31,12 @@ from rfg_adc_plotter.processing.calibration import (
     save_complex_calibration,
     set_calibration_base_value,
 )
-from rfg_adc_plotter.processing.fft import compute_fft_complex_row, compute_fft_mag_row, fft_mag_to_db
+from rfg_adc_plotter.processing.fft import (
+    compute_distance_axis,
+    compute_fft_complex_row,
+    compute_fft_mag_row,
+    fft_mag_to_db,
+)
 from rfg_adc_plotter.processing.formatting import compute_auto_ylim, format_status_kv, parse_spec_clip
 from rfg_adc_plotter.processing.normalization import (
     normalize_by_complex_calibration,
@@ -49,6 +54,7 @@ from rfg_adc_plotter.types import SweepAuxCurves, SweepInfo, SweepPacket
 RAW_PLOT_MAX_POINTS = 2048
 RAW_WATERFALL_MAX_POINTS = 2048
 BSCAN_MAX_POINTS = 256
+BSCAN_DB_RANGE_DEFAULT: Tuple[float, float] = (80.0, 150.0)
 UI_QUEUE_MAXSIZE = 128
 UI_MAX_PACKETS_PER_TICK = 8
 DEBUG_FRAME_LOG_EVERY = 10
@@ -821,6 +827,19 @@ def _db_to_linear_amplitude(values: np.ndarray) -> np.ndarray:
     return np.maximum(out, 0.0).astype(np.float32, copy=False)
 
 
+def parse_bscan_db_range(spec: Optional[str]) -> Tuple[float, float]:
+    """Parse a fixed B-scan dB color window 'min,max'. Falls back to the default."""
+    if spec:
+        try:
+            p0, p1 = str(spec).strip().replace(";", ",").split(",")
+            lo, hi = float(p0), float(p1)
+            if np.isfinite(lo) and np.isfinite(hi) and lo < hi:
+                return (lo, hi)
+        except Exception:
+            pass
+    return BSCAN_DB_RANGE_DEFAULT
+
+
 def compute_background_subtracted_bscan_levels(
     disp_fft_lin: np.ndarray,
     disp_fft: np.ndarray,
@@ -903,6 +922,7 @@ def run_pyqtgraph(args) -> None:
     fft_bins = FFT_LEN // 2 + 1
     spec_clip = parse_spec_clip(getattr(args, "spec_clip", None))
     spec_mean_sec = float(getattr(args, "spec_mean_sec", 0.0))
+    bscan_db_vmin, bscan_db_vmax = parse_bscan_db_range(getattr(args, "bscan_db_range", None))
     runtime = RuntimeState(
         ring=RingBuffer(max_sweeps),
         range_min_ghz=float(SWEEP_FREQ_MIN_GHZ),
@@ -1156,6 +1176,24 @@ def run_pyqtgraph(args) -> None:
     range_max_spin.setValue(runtime.range_max_ghz)
     range_group_layout.addRow("f min", range_min_spin)
     range_group_layout.addRow("f max", range_max_spin)
+    bscan_db_group = QtWidgets.QGroupBox("B-scan дБ шкала")
+    bscan_db_group_layout = QtWidgets.QFormLayout(bscan_db_group)
+    bscan_db_group_layout.setContentsMargins(6, 6, 6, 6)
+    bscan_db_group_layout.setSpacing(6)
+    bscan_db_min_spin = QtWidgets.QDoubleSpinBox()
+    bscan_db_max_spin = QtWidgets.QDoubleSpinBox()
+    for spin in (bscan_db_min_spin, bscan_db_max_spin):
+        spin.setDecimals(1)
+        spin.setRange(-100.0, 400.0)
+        spin.setSingleStep(1.0)
+        try:
+            spin.setSuffix(" dB")
+        except Exception:
+            pass
+    bscan_db_min_spin.setValue(bscan_db_vmin)
+    bscan_db_max_spin.setValue(bscan_db_vmax)
+    bscan_db_group_layout.addRow("дБ мин", bscan_db_min_spin)
+    bscan_db_group_layout.addRow("дБ макс", bscan_db_max_spin)
     fft_mode_label = QtWidgets.QLabel("IFFT режим")
     fft_mode_combo = QtWidgets.QComboBox()
     fft_mode_combo.addItem("Обычный", "direct")
@@ -1305,6 +1343,7 @@ def run_pyqtgraph(args) -> None:
     except Exception:
         pass
     settings_layout.addWidget(range_group)
+    settings_layout.addWidget(bscan_db_group)
     settings_layout.addWidget(calib_group)
     settings_layout.addWidget(complex_calib_group)
     settings_layout.addWidget(tty_range_group)
@@ -1346,6 +1385,13 @@ def run_pyqtgraph(args) -> None:
     last_packet_processed_at: Optional[float] = None
     axis_range_cache: Dict[str, Tuple[float, ...]] = {}
     image_rect_cache: Dict[str, Tuple[float, ...]] = {}
+    bscan_axis_cache: Dict[Tuple, np.ndarray] = {}
+    # Fixed manual dB color window for the normal (no-background) B-scan view.
+    # Never recomputed per frame; only changed by the user via the spin boxes.
+    bscan_manual_levels: Dict[str, float] = {"vmin": bscan_db_vmin, "vmax": bscan_db_vmax}
+    # Frozen levels for the background-subtracted residual view (different scale):
+    # computed once when background is active, held until a reset event clears it.
+    bscan_bg_levels_frozen: Dict[str, Optional[Tuple[float, float]]] = {"held": None}
     curve_has_data_cache: Dict[str, bool] = {}
     item_visibility_cache: Dict[str, bool] = {}
     text_value_cache: Dict[str, str] = {}
@@ -1441,6 +1487,43 @@ def run_pyqtgraph(args) -> None:
         image_rect_cache[key] = values
         return True
 
+    def stable_full_scale_distance_axis() -> Optional[np.ndarray]:
+        """Full-scale B-scan distance axis, computed once per (range, mode).
+
+        The per-sweep ``runtime.ring.distance_axis`` jitters when the reported
+        ``f_max`` varies between sweeps, which rescales the B-scan y-axis every
+        frame. Deriving the axis from the configured range keeps it stable and
+        only recomputes when the operator changes ``f min``/``f max`` or the mode.
+        """
+        key = (
+            round(float(runtime.range_min_ghz), 9),
+            round(float(runtime.range_max_ghz), 9),
+            str(fft_mode),
+        )
+        cached = bscan_axis_cache.get(key)
+        if cached is not None:
+            return cached
+        if display_distance_transform_enabled(fft_mode):
+            # positive_only_exact derives its step from real sweep geometry, so a
+            # synthetic 2-point freq array would be wrong. Hold the first valid
+            # real axis instead (still keyed by mode, so it re-seeds on switch).
+            real_axis = runtime.ring.distance_axis
+            if real_axis is None:
+                return None
+            axis = np.asarray(real_axis, dtype=np.float64).reshape(-1)
+            if axis.size <= 0 or not np.all(np.isfinite(axis)):
+                return None
+        else:
+            synth_freqs = np.asarray(
+                [runtime.range_min_ghz, runtime.range_max_ghz], dtype=np.float64
+            )
+            axis = compute_distance_axis(synth_freqs, fft_bins, mode=fft_mode)
+            if axis is None or axis.size <= 0 or not np.all(np.isfinite(axis)):
+                return None
+        bscan_axis_cache.clear()
+        bscan_axis_cache[key] = axis
+        return axis
+
     def set_item_visible_if_changed(key: str, item, visible: bool) -> bool:
         visible_value = bool(visible)
         if item_visibility_cache.get(key) == visible_value:
@@ -1887,6 +1970,9 @@ def run_pyqtgraph(args) -> None:
         runtime.background_buffer.reset()
         if clear_profile:
             runtime.background_profile = None
+        # Re-freeze the background-subtracted B-scan levels so contrast doesn't
+        # drag an old residual scale across the background on/off transition.
+        bscan_bg_levels_frozen["held"] = None
         runtime.current_fft_complex = None
         runtime.current_fft_mag = None
         runtime.current_fft_db = None
@@ -1905,6 +1991,8 @@ def run_pyqtgraph(args) -> None:
         runtime.ring.reset()
         axis_range_cache.clear()
         image_rect_cache.clear()
+        bscan_axis_cache.clear()
+        bscan_bg_levels_frozen["held"] = None
         runtime.current_distances = None
         runtime.current_fft_complex = None
         runtime.current_fft_mag = None
@@ -2238,6 +2326,20 @@ def run_pyqtgraph(args) -> None:
         finally:
             range_change_in_progress = False
 
+    def set_bscan_db_range() -> None:
+        try:
+            new_min = float(bscan_db_min_spin.value())
+            new_max = float(bscan_db_max_spin.value())
+        except Exception:
+            return
+        if (not np.isfinite(new_min)) or (not np.isfinite(new_max)) or new_min >= new_max:
+            set_status_note("B-scan дБ: мин должен быть меньше макс")
+            return
+        bscan_manual_levels["vmin"] = new_min
+        bscan_manual_levels["vmax"] = new_max
+        set_status_note(f"B-scan дБ: {new_min:.1f}..{new_max:.1f}")
+        runtime.mark_dirty()
+
     def set_working_range() -> None:
         nonlocal range_change_in_progress
         if range_change_in_progress:
@@ -2506,6 +2608,8 @@ def run_pyqtgraph(args) -> None:
             background_enabled = False
         if background_enabled and runtime.background_profile is None:
             set_status_note("фон: профиль не загружен")
+        # Re-freeze residual levels so toggling background recomputes them once.
+        bscan_bg_levels_frozen["held"] = None
         runtime.mark_dirty()
 
     def set_fft_low_cut_percent() -> None:
@@ -2526,6 +2630,7 @@ def run_pyqtgraph(args) -> None:
         except Exception:
             fft_mode = "symmetric"
         runtime.ring.set_fft_mode(fft_mode)
+        bscan_axis_cache.clear()
         reset_background_state(clear_profile=True)
         runtime.current_distances = runtime.ring.distance_axis
         runtime.current_fft_mag = None
@@ -2559,6 +2664,8 @@ def run_pyqtgraph(args) -> None:
     try:
         range_min_spin.valueChanged.connect(lambda _v: set_working_range())
         range_max_spin.valueChanged.connect(lambda _v: set_working_range())
+        bscan_db_min_spin.valueChanged.connect(lambda _v: set_bscan_db_range())
+        bscan_db_max_spin.valueChanged.connect(lambda _v: set_bscan_db_range())
         tty_range_spin.valueChanged.connect(lambda _v: set_tty_range())
         calib_cb.stateChanged.connect(lambda _v: set_calib_enabled())
         complex_calib_cb.stateChanged.connect(lambda _v: set_complex_calib_enabled())
@@ -3729,42 +3836,32 @@ def run_pyqtgraph(args) -> None:
                     log_debug_event("invalid_fft_image", "ui invalid FFT waterfall suppressed")
                     return
 
-                levels = None
+                # Fixed color scale — never recomputed per frame, so the image no
+                # longer "changes"/flickers as new sweeps roll in.
                 if active_background is not None:
-                    levels = compute_background_subtracted_bscan_levels(disp_fft_lin, disp_fft)
+                    # Residuals are on a different scale than absolute dB; use the
+                    # dedicated bg-subtracted levels, computed ONCE and frozen.
+                    levels = bscan_bg_levels_frozen["held"]
                     if levels is None:
-                    try:
-                        finite_rows = np.any(np.isfinite(disp_fft), axis=1)
-                        if np.any(finite_rows):
-                            mean_spec = np.nanmean(disp_fft[finite_rows], axis=1)
-                            if mean_spec.size > 0:
-                                vmin_v = float(np.nanmin(mean_spec))
-                                vmax_v = float(np.nanmax(mean_spec))
-                                if np.isfinite(vmin_v) and np.isfinite(vmax_v) and vmin_v != vmax_v:
-                                    levels = (vmin_v, vmax_v)
-                    except Exception:
-                        levels = None
-                    if levels is None and spec_clip is not None:
-                        try:
-                            vmin_v = float(np.nanpercentile(disp_fft, spec_clip[0]))
-                            vmax_v = float(np.nanpercentile(disp_fft, spec_clip[1]))
-                            if np.isfinite(vmin_v) and np.isfinite(vmax_v) and vmin_v != vmax_v:
-                                levels = (vmin_v, vmax_v)
-                        except Exception:
-                            levels = None
-                    if (
-                        levels is None
-                        and runtime.ring.y_min_fft is not None
-                        and runtime.ring.y_max_fft is not None
-                        and np.isfinite(runtime.ring.y_min_fft)
-                        and np.isfinite(runtime.ring.y_max_fft)
-                        and runtime.ring.y_min_fft != runtime.ring.y_max_fft
-                    ):
-                        levels = (runtime.ring.y_min_fft, runtime.ring.y_max_fft)
+                        levels = compute_background_subtracted_bscan_levels(disp_fft_lin, disp_fft)
+                        if levels is not None:
+                            bscan_bg_levels_frozen["held"] = levels
+                else:
+                    # Normal view: constant manual dB window from the spin boxes.
+                    levels = (bscan_manual_levels["vmin"], bscan_manual_levels["vmax"])
                 disp_fft_display_axis = display_distance_axis_for_mode(disp_fft_axis, fft_mode)
                 if display_distance_transform_enabled(fft_mode) and disp_fft_display_axis.size == disp_fft.shape[0]:
                     disp_fft = disp_fft[::-1, :]
                     disp_fft_display_axis = disp_fft_display_axis[::-1]
+                # Use a stable full-scale distance axis for the y-range/rect so the
+                # B-scan always spans ~0..12 m and never rescales per sweep. Fall
+                # back to the per-frame axis only until a stable axis is available.
+                stable_axis = stable_full_scale_distance_axis()
+                if stable_axis is not None:
+                    distance_bounds = resolve_axis_bounds(
+                        display_distance_axis_for_mode(stable_axis, fft_mode)
+                    )
+                else:
                     distance_bounds = resolve_axis_bounds(disp_fft_display_axis)
                 if distance_bounds is not None:
                     d_min, d_max = distance_bounds