Daemon thread plotting (ultralytics#1561)

* Daemon thread plotting

* remove process_batch

* plot after print

test.py

@@ -3,6 +3,7 @@
 import json
 import os
 from pathlib import Path
+from threading import Thread
 
 import numpy as np
 import torch
@@ -206,10 +207,10 @@ def test(data,
 
         # Plot images
         if plots and batch_i < 3:
-            f = save_dir / f'test_batch{batch_i}_labels.jpg'  # filename
-            plot_images(img, targets, paths, f, names)  # labels
-            f = save_dir / f'test_batch{batch_i}_pred.jpg'
-            plot_images(img, output_to_target(output), paths, f, names)  # predictions
+            f = save_dir / f'test_batch{batch_i}_labels.jpg'  # labels
+            Thread(target=plot_images, args=(img, targets, paths, f, names), daemon=True).start()
+            f = save_dir / f'test_batch{batch_i}_pred.jpg'  # predictions
+            Thread(target=plot_images, args=(img, output_to_target(output), paths, f, names), daemon=True).start()
 
     # Compute statistics
     stats = [np.concatenate(x, 0) for x in zip(*stats)]  # to numpy
@@ -221,13 +222,6 @@ def test(data,
     else:
         nt = torch.zeros(1)
 
-    # Plots
-    if plots:
-        confusion_matrix.plot(save_dir=save_dir, names=list(names.values()))
-        if wandb and wandb.run:
-            wandb.log({"Images": wandb_images})
-            wandb.log({"Validation": [wandb.Image(str(f), caption=f.name) for f in sorted(save_dir.glob('test*.jpg'))]})
-
     # Print results
     pf = '%20s' + '%12.3g' * 6  # print format
     print(pf % ('all', seen, nt.sum(), mp, mr, map50, map))
@@ -242,6 +236,13 @@ def test(data,
     if not training:
         print('Speed: %.1f/%.1f/%.1f ms inference/NMS/total per %gx%g image at batch-size %g' % t)
 
+    # Plots
+    if plots:
+        confusion_matrix.plot(save_dir=save_dir, names=list(names.values()))
+        if wandb and wandb.run:
+            wandb.log({"Images": wandb_images})
+            wandb.log({"Validation": [wandb.Image(str(f), caption=f.name) for f in sorted(save_dir.glob('test*.jpg'))]})
+
     # Save JSON
     if save_json and len(jdict):
         w = Path(weights[0] if isinstance(weights, list) else weights).stem if weights is not None else ''  # weights

train.py

@@ -1,12 +1,13 @@
 import argparse
 import logging
-import math
 import os
 import random
 import time
 from pathlib import Path
+from threading import Thread
 from warnings import warn
 
+import math
 import numpy as np
 import torch.distributed as dist
 import torch.nn as nn
@@ -134,6 +135,7 @@ def train(hyp, opt, device, tb_writer=None, wandb=None):
                                project='YOLOv5' if opt.project == 'runs/train' else Path(opt.project).stem,
                                name=save_dir.stem,
                                id=ckpt.get('wandb_id') if 'ckpt' in locals() else None)
+    loggers = {'wandb': wandb}  # loggers dict
 
     # Resume
     start_epoch, best_fitness = 0, 0.0
@@ -201,11 +203,9 @@ def train(hyp, opt, device, tb_writer=None, wandb=None):
             # cf = torch.bincount(c.long(), minlength=nc) + 1.  # frequency
             # model._initialize_biases(cf.to(device))
             if plots:
-                plot_labels(labels, save_dir=save_dir)
+                Thread(target=plot_labels, args=(labels, save_dir, loggers), daemon=True).start()
                 if tb_writer:
                     tb_writer.add_histogram('classes', c, 0)
-                if wandb:
-                    wandb.log({"Labels": [wandb.Image(str(x), caption=x.name) for x in save_dir.glob('*labels*.png')]})
 
             # Anchors
             if not opt.noautoanchor:
@@ -311,7 +311,7 @@ def train(hyp, opt, device, tb_writer=None, wandb=None):
                 # Plot
                 if plots and ni < 3:
                     f = save_dir / f'train_batch{ni}.jpg'  # filename
-                    plot_images(images=imgs, targets=targets, paths=paths, fname=f)
+                    Thread(target=plot_images, args=(imgs, targets, paths, f), daemon=True).start()
                     # if tb_writer:
                     #     tb_writer.add_image(f, result, dataformats='HWC', global_step=epoch)
                     #     tb_writer.add_graph(model, imgs)  # add model to tensorboard

utils/plots.py

@@ -250,7 +250,7 @@ def plot_study_txt(path='', x=None):  # from utils.plots import *; plot_study_tx
     plt.savefig('test_study.png', dpi=300)
 
 
-def plot_labels(labels, save_dir=''):
+def plot_labels(labels, save_dir=Path(''), loggers=None):
     # plot dataset labels
     c, b = labels[:, 0], labels[:, 1:].transpose()  # classes, boxes
     nc = int(c.max() + 1)  # number of classes
@@ -264,7 +264,7 @@ def plot_labels(labels, save_dir=''):
         sns.pairplot(x, corner=True, diag_kind='hist', kind='scatter', markers='o',
                      plot_kws=dict(s=3, edgecolor=None, linewidth=1, alpha=0.02),
                      diag_kws=dict(bins=50))
-        plt.savefig(Path(save_dir) / 'labels_correlogram.png', dpi=200)
+        plt.savefig(save_dir / 'labels_correlogram.png', dpi=200)
         plt.close()
     except Exception as e:
         pass
@@ -292,9 +292,14 @@ def plot_labels(labels, save_dir=''):
     for a in [0, 1, 2, 3]:
         for s in ['top', 'right', 'left', 'bottom']:
             ax[a].spines[s].set_visible(False)
-    plt.savefig(Path(save_dir) / 'labels.png', dpi=200)
+    plt.savefig(save_dir / 'labels.png', dpi=200)
     plt.close()
 
+    # loggers
+    for k, v in loggers.items() or {}:
+        if k == 'wandb' and v:
+            v.log({"Labels": [v.Image(str(x), caption=x.name) for x in save_dir.glob('*labels*.png')]})
+
 
 def plot_evolution(yaml_file='data/hyp.finetune.yaml'):  # from utils.plots import *; plot_evolution()
     # Plot hyperparameter evolution results in evolve.txt