[Classify]: Allow inference on dirs and videos (#9003)

* allow image dirs

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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* Update predict.py

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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* Update dataloaders.py

* Update predict.py

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* Update predict.py

* Update predict.py

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Glenn Jocher <glenn.jocher@ultralytics.com>

classify/predict.py

@@ -1,6 +1,6 @@
 # YOLOv5 🚀 by Ultralytics, GPL-3.0 license
 """
-Run classification inference on images
+Run classification inference on file/dir/URL/glob
 
 Usage:
     $ python classify/predict.py --weights yolov5s-cls.pt --source data/images/bus.jpg
@@ -11,7 +11,6 @@ import os
 import sys
 from pathlib import Path
 
-import cv2
 import torch.nn.functional as F
 
 FILE = Path(__file__).resolve()
@@ -20,27 +19,31 @@ if str(ROOT) not in sys.path:
     sys.path.append(str(ROOT))  # add ROOT to PATH
 ROOT = Path(os.path.relpath(ROOT, Path.cwd()))  # relative
 
-from classify.train import imshow_cls
 from models.common import DetectMultiBackend
 from utils.augmentations import classify_transforms
-from utils.general import LOGGER, check_requirements, colorstr, increment_path, print_args
+from utils.dataloaders import IMG_FORMATS, VID_FORMATS, LoadImages
+from utils.general import LOGGER, check_file, check_requirements, colorstr, increment_path, print_args
 from utils.torch_utils import select_device, smart_inference_mode, time_sync
 
 
 @smart_inference_mode()
 def run(
         weights=ROOT / 'yolov5s-cls.pt',  # model.pt path(s)
-        source=ROOT / 'data/images/bus.jpg',  # file/dir/URL/glob, 0 for webcam
+        source=ROOT / 'data/images',  # file/dir/URL/glob
         imgsz=224,  # inference size
         device='',  # cuda device, i.e. 0 or 0,1,2,3 or cpu
         half=False,  # use FP16 half-precision inference
         dnn=False,  # use OpenCV DNN for ONNX inference
-        show=True,
         project=ROOT / 'runs/predict-cls',  # save to project/name
         name='exp',  # save to project/name
         exist_ok=False,  # existing project/name ok, do not increment
 ):
-    file = str(source)
+    source = str(source)
+    is_file = Path(source).suffix[1:] in (IMG_FORMATS + VID_FORMATS)
+    is_url = source.lower().startswith(('rtsp://', 'rtmp://', 'http://', 'https://'))
+    if is_url and is_file:
+        source = check_file(source)  # download
+
     seen, dt = 1, [0.0, 0.0, 0.0]
     device = select_device(device)
 
@@ -48,37 +51,36 @@ def run(
     save_dir = increment_path(Path(project) / name, exist_ok=exist_ok)  # increment run
     save_dir.mkdir(parents=True, exist_ok=True)  # make dir
 
-    # Transforms
-    transforms = classify_transforms(imgsz)
-
     # Load model
     model = DetectMultiBackend(weights, device=device, dnn=dnn, fp16=half)
     model.warmup(imgsz=(1, 3, imgsz, imgsz))  # warmup
+    dataset = LoadImages(source, img_size=imgsz, transforms=classify_transforms(imgsz))
+    for path, im, im0s, vid_cap, s in dataset:
+        # Image
+        t1 = time_sync()
+        im = im.unsqueeze(0).to(device)
+        im = im.half() if model.fp16 else im.float()
+        t2 = time_sync()
+        dt[0] += t2 - t1
 
-    # Image
+        # Inference
-    t1 = time_sync()
+        results = model(im)
-    im = cv2.cvtColor(cv2.imread(file), cv2.COLOR_BGR2RGB)
+        t3 = time_sync()
-    im = transforms(im).unsqueeze(0).to(device)
+        dt[1] += t3 - t2
-    im = im.half() if model.fp16 else im.float()
-    t2 = time_sync()
-    dt[0] += t2 - t1
 
-    # Inference
+        # Post-process
-    results = model(im)
+        p = F.softmax(results, dim=1)  # probabilities
-    t3 = time_sync()
+        i = p.argsort(1, descending=True)[:, :5].squeeze().tolist()  # top 5 indices
-    dt[1] += t3 - t2
+        dt[2] += time_sync() - t3
-
+        # if save:
-    p = F.softmax(results, dim=1)  # probabilities
+        #    imshow_cls(im, f=save_dir / Path(path).name, verbose=True)
-    i = p.argsort(1, descending=True)[:, :5].squeeze()  # top 5 indices
+        seen += 1
-    dt[2] += time_sync() - t3
+        LOGGER.info(f"{s}{imgsz}x{imgsz} {', '.join(f'{model.names[j]} {p[0, j]:.2f}' for j in i)}")
-    LOGGER.info(f"image 1/1 {file}: {imgsz}x{imgsz} {', '.join(f'{model.names[j]} {p[0, j]:.2f}' for j in i.tolist())}")
 
     # Print results
     t = tuple(x / seen * 1E3 for x in dt)  # speeds per image
     shape = (1, 3, imgsz, imgsz)
     LOGGER.info(f'Speed: %.1fms pre-process, %.1fms inference, %.1fms post-process per image at shape {shape}' % t)
-    if show:
-        imshow_cls(im, f=save_dir / Path(file).name, verbose=True)
     LOGGER.info(f"Results saved to {colorstr('bold', save_dir)}")
     return p
 
@@ -86,7 +88,7 @@ def run(
 def parse_opt():
     parser = argparse.ArgumentParser()
     parser.add_argument('--weights', nargs='+', type=str, default=ROOT / 'yolov5s-cls.pt', help='model path(s)')
-    parser.add_argument('--source', type=str, default=ROOT / 'data/images/bus.jpg', help='file')
+    parser.add_argument('--source', type=str, default=ROOT / 'data/images', help='file/dir/URL/glob')
     parser.add_argument('--imgsz', '--img', '--img-size', type=int, default=224, help='train, val image size (pixels)')
     parser.add_argument('--device', default='', help='cuda device, i.e. 0 or 0,1,2,3 or cpu')
     parser.add_argument('--half', action='store_true', help='use FP16 half-precision inference')

utils/dataloaders.py

@@ -186,7 +186,7 @@ class _RepeatSampler:
 
 class LoadImages:
     # YOLOv5 image/video dataloader, i.e. `python detect.py --source image.jpg/vid.mp4`
-    def __init__(self, path, img_size=640, stride=32, auto=True):
+    def __init__(self, path, img_size=640, stride=32, auto=True, transforms=None):
         files = []
         for p in sorted(path) if isinstance(path, (list, tuple)) else [path]:
             p = str(Path(p).resolve())
@@ -210,6 +210,7 @@ class LoadImages:
         self.video_flag = [False] * ni + [True] * nv
         self.mode = 'image'
         self.auto = auto
+        self.transforms = transforms  # optional
         if any(videos):
             self.new_video(videos[0])  # new video
         else:
@@ -229,7 +230,7 @@ class LoadImages:
         if self.video_flag[self.count]:
             # Read video
             self.mode = 'video'
-            ret_val, img0 = self.cap.read()
+            ret_val, im0 = self.cap.read()
             while not ret_val:
                 self.count += 1
                 self.cap.release()
@@ -237,7 +238,7 @@ class LoadImages:
                     raise StopIteration
                 path = self.files[self.count]
                 self.new_video(path)
-                ret_val, img0 = self.cap.read()
+                ret_val, im0 = self.cap.read()
 
             self.frame += 1
             s = f'video {self.count + 1}/{self.nf} ({self.frame}/{self.frames}) {path}: '
@@ -245,18 +246,18 @@ class LoadImages:
         else:
             # Read image
             self.count += 1
-            img0 = cv2.imread(path)  # BGR
+            im0 = cv2.imread(path)  # BGR
-            assert img0 is not None, f'Image Not Found {path}'
+            assert im0 is not None, f'Image Not Found {path}'
             s = f'image {self.count}/{self.nf} {path}: '
 
-        # Padded resize
+        if self.transforms:
-        img = letterbox(img0, self.img_size, stride=self.stride, auto=self.auto)[0]
+            im = self.transforms(cv2.cvtColor(im0, cv2.COLOR_BGR2RGB))  # classify transforms
+        else:
+            im = letterbox(im0, self.img_size, stride=self.stride, auto=self.auto)[0]  # padded resize
+            im = im.transpose((2, 0, 1))[::-1]  # HWC to CHW, BGR to RGB
+            im = np.ascontiguousarray(im)  # contiguous
 
-        # Convert
+        return path, im, im0, self.cap, s
-        img = img.transpose((2, 0, 1))[::-1]  # HWC to CHW, BGR to RGB
-        img = np.ascontiguousarray(img)
-
-        return path, img, img0, self.cap, s
 
     def new_video(self, path):
         self.frame = 0