Add segment_ends and Update morphology tips outputs

docs/segment_ends.md

@@ -0,0 +1,51 @@
+## Identify Segment Ends
+
+Find segment tip and inner branch-point coordinates, and sort them by the y-coordinates of the branch points
+
+**plantcv.morphology.segment_ends**(*skel_img, leaf_objects, mask=None, label=None*)
+
+**returns** Re-ordered leaf segments
+
+- **Parameters:**
+    - skel_img - Skeleton image (output from [plantcv.morphology.skeletonize](skeletonize.md))
+    - leaf_objects - Secondary segment objects (output from [plantcv.morphology.segment_sort](segment_sort.md)).
+    - mask - Binary mask for plotting. If provided, the debugging image will be overlaid on the mask (optional).
+    - label - Optional label parameter, modifies the variable name of observations recorded. (default = `pcv.params.sample_label`)
+- **Context:**
+    - Aims to sort leaf objects by biological age. This tends to work somewhat consistently for grass species that have leav
+
+**Reference Images**
+
+![Screenshot](img/documentation_images/segment_ends/setaria_mask.png)
+
+```python
+
+from plantcv import plantcv as pcv
+
+# Set global debug behavior to None (default), "print" (to file), 
+# or "plot" (Jupyter Notebooks or X11)
+pcv.params.debug = "plot"
+
+# Adjust point thickness with the global line_thickness parameter (default = 5)
+pcv.params.line_thickness = 3 
+
+sorted_obs = pcv.morphology.segment_ends(skel_img=skeleton,
+                                         leaf_objects=leaf_objs,
+                                         mask=plant_mask,
+                                         label="leaves")
+
+segmented_img, leaves_labeled = pcv.morphology.segment_id(skel_img=skeleton, 
+                                                          objects=leaf_objs,
+                                                          mask=plant_mask
+# Without ID re-assignment
+segmented_img, leaves_labeled = pcv.morphology.segment_id(skel_img=skeleton, 
+                                                          objects=sorted_obs,
+                                                          mask=plant_mask)
+
+```
+
+*Segment end points Debug*
+
+![Screenshot](img/documentation_images/segment_ends/segment_end_pts.png)
+
+**Source Code:** [Here](https://github.com/danforthcenter/plantcv/blob/main/plantcv/plantcv/morphology/segment_ends.py)

docs/updating.md

@@ -685,6 +685,11 @@ pages for more details on the input and output variable types.
 * post v3.11: labeled_img = **plantcv.morphology.segment_curvature**(*segmented_img, objects, label="default"*)
 * post v4.0: labeled_img = **plantcv.morphology.segment_curvature**(*segmented_img, objects, label=None*)
 
+#### plantcv.morphology.segment_ends 
+
+* pre v4.6: NA
+* post v4.6: **plantcv.morphology.segment_ends**(*skel_img, leaf_objects, mask=None, label=None*)
+
 #### plantcv.morphology.segment_euclidean_length
 
 * pre v3.3: NA

mkdocs.yml

@@ -118,6 +118,7 @@ nav:
         - 'Segment Angles': segment_angle.md
         - 'Combine Segments': segment_combine.md
         - 'Segment Curvature': segment_curvature.md
+        - 'Segment Ends': segment_ends.md
         - 'Segment Euclidean Length': segment_euclidean_length.md
         - 'Segment ID': segment_id.md
         - 'Segment Insertion Angle': segment_insertion_angle.md

plantcv/plantcv/_helpers.py

@@ -1,11 +1,176 @@
 import cv2
 import numpy as np
+from plantcv.plantcv.dilate import dilate
 from plantcv.plantcv.logical_and import logical_and
+from plantcv.plantcv.image_subtract import image_subtract
 from plantcv.plantcv import fatal_error, warn
 from plantcv.plantcv import params
 import pandas as pd
 
 
+def _find_segment_ends(skel_img, leaf_objects, plotting_img, size):
+    """Find both segment ends and sort into tips or inner branchpoints.
+
+    Inputs:
+    skel_img         = Skeletonized image
+    leaf_objects     = List of leaf segments
+    plotting_img     = Mask for debugging, might be a copy of the Skeletonized image
+    size             = Size of inner segment ends (in pixels)
+
+    :param skel_img: numpy.ndarray
+    :param leaf_objects: list
+    :param plotting_img: numpy.ndarray
+    """
+    labeled_img = cv2.cvtColor(plotting_img, cv2.COLOR_GRAY2RGB)
+    tips, _, _ = _find_tips(skel_img)
+    # Initialize list of tip data points
+    labels = []
+    tip_list = []
+    inner_list = []
+
+    # Find segment end coordinates
+    for i in range(len(leaf_objects)):
+        labels.append(i)
+        # Draw leaf objects
+        find_segment_tangents = np.zeros(labeled_img.shape[:2], np.uint8)
+        cv2.drawContours(find_segment_tangents, leaf_objects, i, 255, 1, lineType=8)
+        cv2.drawContours(labeled_img, leaf_objects, i, (150, 150, 150), params.line_thickness, lineType=8)  # segments debug
+        # Prune back ends of leaves
+        pruned_segment = _iterative_prune(find_segment_tangents, size)
+        # Segment ends are the portions pruned off
+        ends = find_segment_tangents - pruned_segment
+        segment_end_obj, _ = _cv2_findcontours(bin_img=ends)
+        # Determine if a segment is segment tip or branch point
+        for j, obj in enumerate(segment_end_obj):
+            segment_plot = np.zeros(skel_img.shape[:2], np.uint8)
+            cv2.drawContours(segment_plot, obj, -1, 255, 1, lineType=8)
+            segment_plot = dilate(segment_plot, 3, 1)
+            overlap_img = logical_and(segment_plot, tips)
+            x, y = segment_end_obj[j].ravel()[:2]
+            coord = (int(x), int(y))
+            # If none of the tips are within a segment_end then it's an insertion segment
+            if np.sum(overlap_img) == 0:
+                inner_list.append(coord)
+                cv2.circle(labeled_img, coord, params.line_thickness, (50, 0, 255), -1)  # Red auricles
+            else:
+                tip_list.append(coord)
+                cv2.circle(labeled_img, coord, params.line_thickness, (0, 255, 0), -1)  # green tips
+
+    return labeled_img, tip_list, inner_list, labels
+
+
+def _iterative_prune(skel_img, size):
+    """Iteratively remove endpoints (tips) from a skeletonized image.
+    The pruning algorithm was inspired by Jean-Patrick Pommier: https://gist.github.com/jeanpat/5712699
+    "Prunes" barbs off a skeleton.
+    Inputs:
+    skel_img    = Skeletonized image
+    size        = Size to get pruned off each branch
+    Returns:
+    pruned_img  = Pruned image
+    :param skel_img: numpy.ndarray
+    :param size: int
+    :return pruned_img: numpy.ndarray
+    """
+    pruned_img = skel_img.copy()
+    # Store debug
+    debug = params.debug
+    params.debug = None
+
+    # Iteratively remove endpoints (tips) from a skeleton
+    for _ in range(0, size):
+        endpoints, _, _ = _find_tips(pruned_img)
+        pruned_img = image_subtract(pruned_img, endpoints)
+
+    # Make debugging image
+    pruned_plot = np.zeros(skel_img.shape[:2], np.uint8)
+    pruned_plot = cv2.cvtColor(pruned_plot, cv2.COLOR_GRAY2RGB)
+    skel_obj, skel_hierarchy = _cv2_findcontours(bin_img=pruned_img)
+    pruned_obj, pruned_hierarchy = _cv2_findcontours(bin_img=pruned_img)
+
+    # Reset debug mode
+    params.debug = debug
+
+    cv2.drawContours(pruned_plot, skel_obj, -1, (0, 0, 255), params.line_thickness,
+                     lineType=8, hierarchy=skel_hierarchy)
+    cv2.drawContours(pruned_plot, pruned_obj, -1, (255, 255, 255), params.line_thickness,
+                     lineType=8, hierarchy=pruned_hierarchy)
+
+    return pruned_img
+
+
+def _find_tips(skel_img, mask=None):
+    """Helper function to find tips in skeletonized image.
+    The endpoints algorithm was inspired by Jean-Patrick Pommier: https://gist.github.com/jeanpat/5712699
+
+    Inputs:
+    skel_img    = Skeletonized image
+    mask        = (Optional) binary mask for debugging. If provided, debug image will be overlaid on the mask.
+    label       = Optional label parameter, modifies the variable name of
+                  observations recorded (default = pcv.params.sample_label).
+    Returns:
+    tip_img   = Image with just tips, rest 0
+
+    :param skel_img: numpy.ndarray
+    :param mask: numpy.ndarray
+    :param label: str
+    :return tip_img: numpy.ndarray
+    """
+    # In a kernel: 1 values line up with 255s, -1s line up with 0s, and 0s correspond to dont care
+    endpoint1 = np.array([[-1, -1, -1],
+                          [-1, 1, -1],
+                          [0, 1,  0]])
+    endpoint2 = np.array([[-1, -1, -1],
+                          [-1, 1, 0],
+                          [-1, 0, 1]])
+
+    endpoint3 = np.rot90(endpoint1)
+    endpoint4 = np.rot90(endpoint2)
+    endpoint5 = np.rot90(endpoint3)
+    endpoint6 = np.rot90(endpoint4)
+    endpoint7 = np.rot90(endpoint5)
+    endpoint8 = np.rot90(endpoint6)
+
+    endpoints = [endpoint1, endpoint2, endpoint3, endpoint4, endpoint5, endpoint6, endpoint7, endpoint8]
+    tip_img = np.zeros(skel_img.shape[:2], dtype=int)
+    for endpoint in endpoints:
+        tip_img = np.logical_or(cv2.morphologyEx(skel_img, op=cv2.MORPH_HITMISS, kernel=endpoint,
+                                                 borderType=cv2.BORDER_CONSTANT, borderValue=0), tip_img)
+    tip_img = tip_img.astype(np.uint8) * 255
+    # Store debug
+    debug = params.debug
+    params.debug = None
+    tip_objects, _ = _cv2_findcontours(bin_img=tip_img)
+
+    if mask is None:
+        # Make debugging image
+        dilated_skel = dilate(skel_img, params.line_thickness, 1)
+        tip_plot = cv2.cvtColor(dilated_skel, cv2.COLOR_GRAY2RGB)
+
+    else:
+        # Make debugging image on mask
+        mask_copy = mask.copy()
+        tip_plot = cv2.cvtColor(mask_copy, cv2.COLOR_GRAY2RGB)
+        skel_obj, skel_hier = _cv2_findcontours(bin_img=skel_img)
+        cv2.drawContours(tip_plot, skel_obj, -1, (150, 150, 150), params.line_thickness,
+                         lineType=8, hierarchy=skel_hier)
+
+    # Initialize list of tip data points
+    tip_list = []
+    tip_labels = []
+    for i, tip in enumerate(tip_objects):
+        x, y = tip.ravel()[:2]
+        coord = (int(x), int(y))
+        tip_list.append(coord)
+        tip_labels.append(i)
+        cv2.circle(tip_plot, (x, y), params.line_thickness, (0, 255, 0), -1)
+
+    # Reset debug mode
+    params.debug = debug
+
+    return tip_img, tip_list, tip_labels
+
+
 def _hough_circle(gray_img, mindist, candec, accthresh, minradius, maxradius, maxfound=None):
     """
     Hough Circle Detection

plantcv/plantcv/morphology/__init__.py

@@ -1,6 +1,5 @@
 from plantcv.plantcv.morphology.find_branch_pts import find_branch_pts
 from plantcv.plantcv.morphology.find_tips import find_tips
-from plantcv.plantcv.morphology._iterative_prune import _iterative_prune
 from plantcv.plantcv.morphology.segment_skeleton import segment_skeleton
 from plantcv.plantcv.morphology.segment_sort import segment_sort
 from plantcv.plantcv.morphology.prune import prune
@@ -16,8 +15,10 @@
 from plantcv.plantcv.morphology.segment_combine import segment_combine
 from plantcv.plantcv.morphology.analyze_stem import analyze_stem
 from plantcv.plantcv.morphology.fill_segments import fill_segments
+from plantcv.plantcv.morphology.segment_ends import segment_ends
 
-__all__ = ["find_branch_pts", "find_tips", "prune", "skeletonize", "check_cycles", "segment_skeleton", "segment_angle",
+__all__ = ["find_branch_pts", "find_tips", "prune", "skeletonize", "check_cycles",
+           "segment_skeleton", "segment_angle",
            "segment_path_length", "segment_euclidean_length", "segment_curvature", "segment_sort", "segment_id",
-           "segment_tangent_angle", "segment_insertion_angle", "segment_combine", "_iterative_prune", "analyze_stem",
-           "fill_segments"]
+           "segment_tangent_angle", "segment_insertion_angle", "segment_combine", "analyze_stem",
+           "fill_segments", "segment_ends"]