Add features count label

Add label that shows the numbers of features found as
the mass slider moves.

src/napari_psf_extractor/extractor.py

@@ -3,8 +3,8 @@
 import psf_extractor as psfe
 import trackpy
 
-from napari_psf_extractor.utils import crop_to_bbox
 from napari_psf_extractor.plotting import plot_mass_range
+from napari_psf_extractor.utils import crop_to_bbox
 
 
 def get_features_plot_data(plot_widget, mip, dx, dy, mass):
@@ -37,7 +37,7 @@ def get_features_plot_data(plot_widget, mip, dx, dy, mass):
     # Plot features
     features_init = trackpy.locate(mip, diameter=[dy, dx]).reset_index(drop=True)
 
-    plot_mass_range(mip=mip, ax=ax, mass=mass, features=features_init)
+    feature_count = plot_mass_range(mip=mip, ax=ax, mass=mass, features=features_init)
     plot_widget.canvas.draw()
 
     # Fetch plot matplotlib data from buffer
@@ -57,7 +57,7 @@ def get_features_plot_data(plot_widget, mip, dx, dy, mass):
 
     data = cv2.resize(data, dsize=(mip.shape[1], mip.shape[0]), interpolation=cv2.INTER_NEAREST)
 
-    return data, features_init
+    return data, features_init, feature_count
 
 
 def extract_psf(min_mass, max_mass, stack, features, wx, wy, wz):

src/napari_psf_extractor/features.py

@@ -5,6 +5,7 @@
 from napari._qt.qthreading import thread_worker
 from napari.utils.notifications import show_error
 from psf_extractor.plotting import fire
+from qtpy.QtWidgets import QLabel
 
 from napari_psf_extractor.extractor import get_features_plot_data
 
@@ -16,8 +17,10 @@ def __init__(self, widget):
         self.lock = threading.Lock()
 
         self.data = None
+        self.count = None
         self.features_init = None
-        self.features_layer = None
+        self.layer = None
+        self.label = QLabel(f"Features found: {self.count}")
 
     @thread_worker
     def update_factory(self):
@@ -29,7 +32,7 @@ def update_factory(self):
             pass
 
         if self.widget.mip is not None and isinstance(self.widget.mip, np.ndarray):
-            self.data, self.features_init = get_features_plot_data(
+            self.data, self.features_init, self.count = get_features_plot_data(
                 self.widget.plot_fig,
                 self.widget.mip,
                 self.widget.dx, self.widget.dy,
@@ -66,10 +69,11 @@ def callback(self, curr_range):
         # Create features layer if it doesn't exist
         if not self.layer_exists("Features"):
             cmap = napari.utils.Colormap(fire.colors, display_name=fire.name)
-            self.features_layer = self.widget.viewer.add_image(data=self.data, colormap=cmap, name='Features')
+            self.layer = self.widget.viewer.add_image(data=self.data, colormap=cmap, name='Features')
 
         # Update features layer
-        self.features_layer.data = self.data
+        self.layer.data = self.data
+        self.label.setText(f"Features found: {self.count}")
         self.widget.status.stop_animation()
         self.lock.release()
 

src/napari_psf_extractor/plotting.py

@@ -4,6 +4,26 @@
 
 
 def plot_mass_range(ax, mip, mass, features):
+    """
+    Plot the features in the mass range [mass[0], mass[1]].
+
+    Parameters
+    ----------
+    ax : matplotlib.axes.Axes
+        The axes to plot on.
+    mip : numpy.ndarray
+        The maximum intensity projection of the image stack.
+    mass : tuple
+        The mass range to plot.
+    features : pandas.DataFrame
+        The features to plot.
+
+    Returns
+    -------
+    int
+        The number of features found.
+    """
+
     # Enhance contrast in MIP (by taking the log)
     s = 1 / mip[mip != 0].min()  # scaling factor (such that log(min) = 0
     mip_log = np.log(s * mip,
@@ -25,3 +45,5 @@ def plot_mass_range(ax, mip, mass, features):
     ax.imshow(background, cmap=fire)
     ax.plot(df['x'], df['y'], ls='', color='#00ff00',
             marker='o', ms=7, mfc='none', mew=1)
+
+    return len(df)

src/napari_psf_extractor/widget.py

@@ -1,16 +1,16 @@
 from typing import TYPE_CHECKING
 
 import numpy as np
-from matplotlib import pyplot as plt
+import psf_extractor as psfe
 from magicgui import magicgui
+from matplotlib import pyplot as plt
 from napari.utils.notifications import show_error
-import psf_extractor as psfe
 from qtpy.QtWidgets import QWidget, QVBoxLayout, QPushButton, QFileDialog
 
 from napari_psf_extractor.components.sliders import RangeSlider
+from napari_psf_extractor.components.statusbar import StatusMessage
 from napari_psf_extractor.extractor import extract_psf
 from napari_psf_extractor.features import Features
-from napari_psf_extractor.components.statusbar import StatusMessage
 from napari_psf_extractor.utils import normalize
 
 # Hide napari imports from type support and autocompletion
@@ -93,6 +93,8 @@ def param_setter(
 
         self.layout().addWidget(param_setter.native)
         self.layout().addWidget(self.mass_slider)
+        self.layout().addWidget(self.features.label)
+        self.layout().addStretch(1)
         self.layout().addWidget(self.save_button)
 
         # ---------------
@@ -135,13 +137,15 @@ def reset(self):
 
         self.mass_slider.hide()
         self.save_button.hide()
+        self.features.label.hide()
 
     def refresh(self):
         """
         Refresh the widget and move to the next state.
         """
         if self.state == 0:
             self.mass_slider.reset()
+            self.features.label.show()
             self.mass_slider.show()
             self.save_button.show()