def __init__()

in torchbenchmark/models/yolov3/yolo_utils/datasets.py [0:0]


    def __init__(self, path, img_size=416, batch_size=16, augment=False, hyp=None, rect=False, image_weights=False,
                 cache_images=False, single_cls=False, pad=0.0):
        try:
            path = str(Path(path))  # os-agnostic
            parent = str(Path(path).parent) + os.sep
            if os.path.isfile(path):  # file
                with open(path, 'r') as f:
                    f = f.read().splitlines()
                    f = [x.replace('./', parent) if x.startswith('./') else x for x in f]  # local to global path
            elif os.path.isdir(path):  # folder
                f = glob.iglob(path + os.sep + '*.*')
            else:
                raise Exception('%s does not exist' % path)
            self.img_files = [x.replace('/', os.sep) for x in f if os.path.splitext(x)[-1].lower() in img_formats]
        except:
            raise Exception('Error loading data from %s. See %s' % (path, help_url))

        n = len(self.img_files)
        assert n > 0, 'No images found in %s. See %s' % (path, help_url)
        bi = np.floor(np.arange(n) / batch_size).astype(np.int)  # batch index
        nb = bi[-1] + 1  # number of batches

        self.n = n  # number of images
        self.batch = bi  # batch index of image
        self.img_size = img_size
        self.augment = augment
        self.hyp = hyp
        self.image_weights = image_weights
        self.rect = False if image_weights else rect
        self.mosaic = self.augment and not self.rect  # load 4 images at a time into a mosaic (only during training)

        # Define labels
        self.label_files = [x.replace('images', 'labels').replace(os.path.splitext(x)[-1], '.txt')
                            for x in self.img_files]

        # Read image shapes (wh)
        sp = path.replace('.txt', '') + '.shapes'  # shapefile path
        try:
            with open(sp, 'r') as f:  # read existing shapefile
                s = [x.split() for x in f.read().splitlines()]
                assert len(s) == n, 'Shapefile out of sync'
        except:
            s = [exif_size(Image.open(f)) for f in tqdm(self.img_files, desc='Reading image shapes')]
            np.savetxt(sp, s, fmt='%g')  # overwrites existing (if any)

        self.shapes = np.array(s, dtype=np.float64)

        # Rectangular Training  https://github.com/ultralytics/yolov3/issues/232
        if self.rect:
            # Sort by aspect ratio
            s = self.shapes  # wh
            ar = s[:, 1] / s[:, 0]  # aspect ratio
            irect = ar.argsort()
            self.img_files = [self.img_files[i] for i in irect]
            self.label_files = [self.label_files[i] for i in irect]
            self.shapes = s[irect]  # wh
            ar = ar[irect]

            # Set training image shapes
            shapes = [[1, 1]] * nb
            for i in range(nb):
                ari = ar[bi == i]
                mini, maxi = ari.min(), ari.max()
                if maxi < 1:
                    shapes[i] = [maxi, 1]
                elif mini > 1:
                    shapes[i] = [1, 1 / mini]

            self.batch_shapes = np.ceil(np.array(shapes) * img_size / 32. + pad).astype(np.int) * 32

        # Cache labels
        self.imgs = [None] * n
        self.labels = [np.zeros((0, 5), dtype=np.float32)] * n
        create_datasubset, extract_bounding_boxes, labels_loaded = False, False, False
        nm, nf, ne, ns, nd = 0, 0, 0, 0, 0  # number missing, found, empty, datasubset, duplicate
        np_labels_path = str(Path(self.label_files[0]).parent) + '.npy'  # saved labels in *.npy file
        if os.path.isfile(np_labels_path):
            s = np_labels_path  # print string
            x = np.load(np_labels_path, allow_pickle=True)
            if len(x) == n:
                self.labels = x
                labels_loaded = True
        else:
            s = path.replace('images', 'labels')

        pbar = tqdm(self.label_files)
        for i, file in enumerate(pbar):
            if labels_loaded:
                l = self.labels[i]
                # np.savetxt(file, l, '%g')  # save *.txt from *.npy file
            else:
                try:
                    with open(file, 'r') as f:
                        l = np.array([x.split() for x in f.read().splitlines()], dtype=np.float32)
                except:
                    nm += 1  # print('missing labels for image %s' % self.img_files[i])  # file missing
                    continue

            if l.shape[0]:
                assert l.shape[1] == 5, '> 5 label columns: %s' % file
                assert (l >= 0).all(), 'negative labels: %s' % file
                assert (l[:, 1:] <= 1).all(), 'non-normalized or out of bounds coordinate labels: %s' % file
                if np.unique(l, axis=0).shape[0] < l.shape[0]:  # duplicate rows
                    nd += 1  # print('WARNING: duplicate rows in %s' % self.label_files[i])  # duplicate rows
                if single_cls:
                    l[:, 0] = 0  # force dataset into single-class mode
                self.labels[i] = l
                nf += 1  # file found

                # Create subdataset (a smaller dataset)
                if create_datasubset and ns < 1E4:
                    if ns == 0:
                        create_folder(path='./datasubset')
                        os.makedirs('./datasubset/images')
                    exclude_classes = 43
                    if exclude_classes not in l[:, 0]:
                        ns += 1
                        # shutil.copy(src=self.img_files[i], dst='./datasubset/images/')  # copy image
                        with open('./datasubset/images.txt', 'a') as f:
                            f.write(self.img_files[i] + '\n')

                # Extract object detection boxes for a second stage classifier
                if extract_bounding_boxes:
                    p = Path(self.img_files[i])
                    img = cv2.imread(str(p))
                    h, w = img.shape[:2]
                    for j, x in enumerate(l):
                        f = '%s%sclassifier%s%g_%g_%s' % (p.parent.parent, os.sep, os.sep, x[0], j, p.name)
                        if not os.path.exists(Path(f).parent):
                            os.makedirs(Path(f).parent)  # make new output folder

                        b = x[1:] * [w, h, w, h]  # box
                        b[2:] = b[2:].max()  # rectangle to square
                        b[2:] = b[2:] * 1.3 + 30  # pad
                        b = xywh2xyxy(b.reshape(-1, 4)).ravel().astype(np.int)

                        b[[0, 2]] = np.clip(b[[0, 2]], 0, w)  # clip boxes outside of image
                        b[[1, 3]] = np.clip(b[[1, 3]], 0, h)
                        assert cv2.imwrite(f, img[b[1]:b[3], b[0]:b[2]]), 'Failure extracting classifier boxes'
            else:
                ne += 1  # print('empty labels for image %s' % self.img_files[i])  # file empty
                # os.system("rm '%s' '%s'" % (self.img_files[i], self.label_files[i]))  # remove

        assert nf > 0 or n == 20288, 'No labels found in %s. See %s' % (os.path.dirname(file) + os.sep, help_url)
        if not labels_loaded and n > 1000:
            print('Saving labels to %s for faster future loading' % np_labels_path)
            np.save(np_labels_path, self.labels)  # save for next time

        # Cache images into memory for faster training (WARNING: large datasets may exceed system RAM)
        if cache_images:  # if training
            gb = 0  # Gigabytes of cached images
            pbar = tqdm(range(len(self.img_files)), desc='Caching images')
            self.img_hw0, self.img_hw = [None] * n, [None] * n
            for i in pbar:  # max 10k images
                self.imgs[i], self.img_hw0[i], self.img_hw[i] = load_image(self, i)  # img, hw_original, hw_resized
                gb += self.imgs[i].nbytes

        # Detect corrupted images https://medium.com/joelthchao/programmatically-detect-corrupted-image-8c1b2006c3d3
        detect_corrupted_images = False
        if detect_corrupted_images:
            from skimage import io  # conda install -c conda-forge scikit-image
            for file in tqdm(self.img_files, desc='Detecting corrupted images'):
                try:
                    _ = io.imread(file)
                except:
                    print('Corrupted image detected: %s' % file)