general.py 28.6 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704
# YOLOv5 general utils

import glob
import logging
import math
import os
import platform
import random
import re
import subprocess
import time
from itertools import repeat
from multiprocessing.pool import ThreadPool
from pathlib import Path

import cv2
import numpy as np
import pandas as pd
import pkg_resources as pkg
import torch
import torchvision
import yaml

from utils.google_utils import gsutil_getsize
from utils.metrics import fitness
from utils.torch_utils import init_torch_seeds

# Settings
torch.set_printoptions(linewidth=320, precision=5, profile='long')
np.set_printoptions(linewidth=320, formatter={'float_kind': '{:11.5g}'.format})  # format short g, %precision=5
pd.options.display.max_columns = 10
cv2.setNumThreads(0)  # prevent OpenCV from multithreading (incompatible with PyTorch DataLoader)
os.environ['NUMEXPR_MAX_THREADS'] = str(min(os.cpu_count(), 8))  # NumExpr max threads


def set_logging(rank=-1, verbose=True):
    logging.basicConfig(
        format="%(message)s",
        level=logging.INFO if (verbose and rank in [-1, 0]) else logging.WARN)


def init_seeds(seed=0):
    # Initialize random number generator (RNG) seeds
    random.seed(seed)
    np.random.seed(seed)
    init_torch_seeds(seed)


def get_latest_run(search_dir='.'):
    # Return path to most recent 'last.pt' in /runs (i.e. to --resume from)
    last_list = glob.glob(f'{search_dir}/**/last*.pt', recursive=True)
    return max(last_list, key=os.path.getctime) if last_list else ''


def is_docker():
    # Is environment a Docker container?
    return Path('/workspace').exists()  # or Path('/.dockerenv').exists()


def is_colab():
    # Is environment a Google Colab instance?
    try:
        import google.colab
        return True
    except Exception as e:
        return False


def is_pip():
    # Is file in a pip package?
    return 'site-packages' in Path(__file__).absolute().parts


def emojis(str=''):
    # Return platform-dependent emoji-safe version of string
    return str.encode().decode('ascii', 'ignore') if platform.system() == 'Windows' else str


def file_size(file):
    # Return file size in MB
    return Path(file).stat().st_size / 1e6


def check_online():
    # Check internet connectivity
    import socket
    try:
        socket.create_connection(("1.1.1.1", 443), 5)  # check host accesability
        return True
    except OSError:
        return False


def check_git_status():
    # Recommend 'git pull' if code is out of date
    print(colorstr('github: '), end='')
    try:
        assert Path('.git').exists(), 'skipping check (not a git repository)'
        assert not is_docker(), 'skipping check (Docker image)'
        assert check_online(), 'skipping check (offline)'

        cmd = 'git fetch && git config --get remote.origin.url'
        url = subprocess.check_output(cmd, shell=True).decode().strip().rstrip('.git')  # github repo url
        branch = subprocess.check_output('git rev-parse --abbrev-ref HEAD', shell=True).decode().strip()  # checked out
        n = int(subprocess.check_output(f'git rev-list {branch}..origin/master --count', shell=True))  # commits behind
        if n > 0:
            s = f"⚠️ WARNING: code is out of date by {n} commit{'s' * (n > 1)}. " \
                f"Use 'git pull' to update or 'git clone {url}' to download latest."
        else:
            s = f'up to date with {url} ✅'
        print(emojis(s))  # emoji-safe
    except Exception as e:
        print(e)


def check_python(minimum='3.7.0', required=True):
    # Check current python version vs. required python version
    current = platform.python_version()
    result = pkg.parse_version(current) >= pkg.parse_version(minimum)
    if required:
        assert result, f'Python {minimum} required by YOLOv5, but Python {current} is currently installed'
    return result


def check_requirements(requirements='requirements.txt', exclude=()):
    # Check installed dependencies meet requirements (pass *.txt file or list of packages)
    prefix = colorstr('red', 'bold', 'requirements:')
    check_python()  # check python version
    if isinstance(requirements, (str, Path)):  # requirements.txt file
        file = Path(requirements)
        if not file.exists():
            print(f"{prefix} {file.resolve()} not found, check failed.")
            return
        requirements = [f'{x.name}{x.specifier}' for x in pkg.parse_requirements(file.open()) if x.name not in exclude]
    else:  # list or tuple of packages
        requirements = [x for x in requirements if x not in exclude]

    n = 0  # number of packages updates
    for r in requirements:
        try:
            pkg.require(r)
        except Exception as e:  # DistributionNotFound or VersionConflict if requirements not met
            n += 1
            print(f"{prefix} {r} not found and is required by YOLOv5, attempting auto-update...")
            try:
                print(subprocess.check_output(f"pip install '{r}'", shell=True).decode())
            except Exception as e:
                print(f'{prefix} {e}')

    if n:  # if packages updated
        source = file.resolve() if 'file' in locals() else requirements
        s = f"{prefix} {n} package{'s' * (n > 1)} updated per {source}\n" \
            f"{prefix} ⚠️ {colorstr('bold', 'Restart runtime or rerun command for updates to take effect')}\n"
        print(emojis(s))  # emoji-safe


def check_img_size(img_size, s=32):
    # Verify img_size is a multiple of stride s
    new_size = make_divisible(img_size, int(s))  # ceil gs-multiple
    if new_size != img_size:
        print('WARNING: --img-size %g must be multiple of max stride %g, updating to %g' % (img_size, s, new_size))
    return new_size


def check_imshow():
    # Check if environment supports image displays
    try:
        assert not is_docker(), 'cv2.imshow() is disabled in Docker environments'
        assert not is_colab(), 'cv2.imshow() is disabled in Google Colab environments'
        cv2.imshow('test', np.zeros((1, 1, 3)))
        cv2.waitKey(1)
        cv2.destroyAllWindows()
        cv2.waitKey(1)
        return True
    except Exception as e:
        print(f'WARNING: Environment does not support cv2.imshow() or PIL Image.show() image displays\n{e}')
        return False


def check_file(file):
    # Search/download file (if necessary) and return path
    file = str(file)  # convert to str()
    if Path(file).is_file() or file == '':  # exists
        return file
    elif file.startswith(('http://', 'https://')):  # download
        url, file = file, Path(file).name
        print(f'Downloading {url} to {file}...')
        torch.hub.download_url_to_file(url, file)
        assert Path(file).exists() and Path(file).stat().st_size > 0, f'File download failed: {url}'  # check
        return file
    else:  # search
        files = glob.glob('./**/' + file, recursive=True)  # find file
        assert len(files), f'File not found: {file}'  # assert file was found
        assert len(files) == 1, f"Multiple files match '{file}', specify exact path: {files}"  # assert unique
        return files[0]  # return file


def check_dataset(dict):
    # Download dataset if not found locally
    val, s = dict.get('val'), dict.get('download')
    if val and len(val):
        val = [Path(x).resolve() for x in (val if isinstance(val, list) else [val])]  # val path
        if not all(x.exists() for x in val):
            print('\nWARNING: Dataset not found, nonexistent paths: %s' % [str(x) for x in val if not x.exists()])
            if s and len(s):  # download script
                if s.startswith('http') and s.endswith('.zip'):  # URL
                    f = Path(s).name  # filename
                    print(f'Downloading {s} ...')
                    torch.hub.download_url_to_file(s, f)
                    r = os.system(f'unzip -q {f} -d ../ && rm {f}')  # unzip
                elif s.startswith('bash '):  # bash script
                    print(f'Running {s} ...')
                    r = os.system(s)
                else:  # python script
                    r = exec(s)  # return None
                print('Dataset autodownload %s\n' % ('success' if r in (0, None) else 'failure'))  # print result
            else:
                raise Exception('Dataset not found.')


def download(url, dir='.', unzip=True, delete=True, curl=False, threads=1):
    # Multi-threaded file download and unzip function
    def download_one(url, dir):
        # Download 1 file
        f = dir / Path(url).name  # filename
        if not f.exists():
            print(f'Downloading {url} to {f}...')
            if curl:
                os.system(f"curl -L '{url}' -o '{f}' --retry 9 -C -")  # curl download, retry and resume on fail
            else:
                torch.hub.download_url_to_file(url, f, progress=True)  # torch download
        if unzip and f.suffix in ('.zip', '.gz'):
            print(f'Unzipping {f}...')
            if f.suffix == '.zip':
                s = f'unzip -qo {f} -d {dir} && rm {f}'  # unzip -quiet -overwrite
            elif f.suffix == '.gz':
                s = f'tar xfz {f} --directory {f.parent}'  # unzip
            if delete:  # delete zip file after unzip
                s += f' && rm {f}'
            os.system(s)

    dir = Path(dir)
    dir.mkdir(parents=True, exist_ok=True)  # make directory
    if threads > 1:
        pool = ThreadPool(threads)
        pool.imap(lambda x: download_one(*x), zip(url, repeat(dir)))  # multi-threaded
        pool.close()
        pool.join()
    else:
        for u in tuple(url) if isinstance(url, str) else url:
            download_one(u, dir)


def make_divisible(x, divisor):
    # Returns x evenly divisible by divisor
    return math.ceil(x / divisor) * divisor


def clean_str(s):
    # Cleans a string by replacing special characters with underscore _
    return re.sub(pattern="[|@#!¡·$€%&()=?¿^*;:,¨´><+]", repl="_", string=s)


def one_cycle(y1=0.0, y2=1.0, steps=100):
    # lambda function for sinusoidal ramp from y1 to y2
    return lambda x: ((1 - math.cos(x * math.pi / steps)) / 2) * (y2 - y1) + y1


def colorstr(*input):
    # Colors a string https://en.wikipedia.org/wiki/ANSI_escape_code, i.e.  colorstr('blue', 'hello world')
    *args, string = input if len(input) > 1 else ('blue', 'bold', input[0])  # color arguments, string
    colors = {'black': '\033[30m',  # basic colors
              'red': '\033[31m',
              'green': '\033[32m',
              'yellow': '\033[33m',
              'blue': '\033[34m',
              'magenta': '\033[35m',
              'cyan': '\033[36m',
              'white': '\033[37m',
              'bright_black': '\033[90m',  # bright colors
              'bright_red': '\033[91m',
              'bright_green': '\033[92m',
              'bright_yellow': '\033[93m',
              'bright_blue': '\033[94m',
              'bright_magenta': '\033[95m',
              'bright_cyan': '\033[96m',
              'bright_white': '\033[97m',
              'end': '\033[0m',  # misc
              'bold': '\033[1m',
              'underline': '\033[4m'}
    return ''.join(colors[x] for x in args) + f'{string}' + colors['end']


def labels_to_class_weights(labels, nc=80):
    # Get class weights (inverse frequency) from training labels
    if labels[0] is None:  # no labels loaded
        return torch.Tensor()

    labels = np.concatenate(labels, 0)  # labels.shape = (866643, 5) for COCO
    classes = labels[:, 0].astype(np.int)  # labels = [class xywh]
    weights = np.bincount(classes, minlength=nc)  # occurrences per class

    # Prepend gridpoint count (for uCE training)
    # gpi = ((320 / 32 * np.array([1, 2, 4])) ** 2 * 3).sum()  # gridpoints per image
    # weights = np.hstack([gpi * len(labels)  - weights.sum() * 9, weights * 9]) ** 0.5  # prepend gridpoints to start

    weights[weights == 0] = 1  # replace empty bins with 1
    weights = 1 / weights  # number of targets per class
    weights /= weights.sum()  # normalize
    return torch.from_numpy(weights)


def labels_to_image_weights(labels, nc=80, class_weights=np.ones(80)):
    # Produces image weights based on class_weights and image contents
    class_counts = np.array([np.bincount(x[:, 0].astype(np.int), minlength=nc) for x in labels])
    image_weights = (class_weights.reshape(1, nc) * class_counts).sum(1)
    # index = random.choices(range(n), weights=image_weights, k=1)  # weight image sample
    return image_weights


def coco80_to_coco91_class():  # converts 80-index (val2014) to 91-index (paper)
    # https://tech.amikelive.com/node-718/what-object-categories-labels-are-in-coco-dataset/
    # a = np.loadtxt('data/coco.names', dtype='str', delimiter='\n')
    # b = np.loadtxt('data/coco_paper.names', dtype='str', delimiter='\n')
    # x1 = [list(a[i] == b).index(True) + 1 for i in range(80)]  # darknet to coco
    # x2 = [list(b[i] == a).index(True) if any(b[i] == a) else None for i in range(91)]  # coco to darknet
    x = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 27, 28, 31, 32, 33, 34,
         35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63,
         64, 65, 67, 70, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 84, 85, 86, 87, 88, 89, 90]
    return x


def xyxy2xywh(x):
    # Convert nx4 boxes from [x1, y1, x2, y2] to [x, y, w, h] where xy1=top-left, xy2=bottom-right
    y = x.clone() if isinstance(x, torch.Tensor) else np.copy(x)
    y[:, 0] = (x[:, 0] + x[:, 2]) / 2  # x center
    y[:, 1] = (x[:, 1] + x[:, 3]) / 2  # y center
    y[:, 2] = x[:, 2] - x[:, 0]  # width
    y[:, 3] = x[:, 3] - x[:, 1]  # height
    return y


def xywh2xyxy(x):
    # Convert nx4 boxes from [x, y, w, h] to [x1, y1, x2, y2] where xy1=top-left, xy2=bottom-right
    y = x.clone() if isinstance(x, torch.Tensor) else np.copy(x)
    y[:, 0] = x[:, 0] - x[:, 2] / 2  # top left x
    y[:, 1] = x[:, 1] - x[:, 3] / 2  # top left y
    y[:, 2] = x[:, 0] + x[:, 2] / 2  # bottom right x
    y[:, 3] = x[:, 1] + x[:, 3] / 2  # bottom right y
    return y


def xywhn2xyxy(x, w=640, h=640, padw=0, padh=0):
    # Convert nx4 boxes from [x, y, w, h] normalized to [x1, y1, x2, y2] where xy1=top-left, xy2=bottom-right
    y = x.clone() if isinstance(x, torch.Tensor) else np.copy(x)
    y[:, 0] = w * (x[:, 0] - x[:, 2] / 2) + padw  # top left x
    y[:, 1] = h * (x[:, 1] - x[:, 3] / 2) + padh  # top left y
    y[:, 2] = w * (x[:, 0] + x[:, 2] / 2) + padw  # bottom right x
    y[:, 3] = h * (x[:, 1] + x[:, 3] / 2) + padh  # bottom right y
    return y


def xyn2xy(x, w=640, h=640, padw=0, padh=0):
    # Convert normalized segments into pixel segments, shape (n,2)
    y = x.clone() if isinstance(x, torch.Tensor) else np.copy(x)
    y[:, 0] = w * x[:, 0] + padw  # top left x
    y[:, 1] = h * x[:, 1] + padh  # top left y
    return y


def segment2box(segment, width=640, height=640):
    # Convert 1 segment label to 1 box label, applying inside-image constraint, i.e. (xy1, xy2, ...) to (xyxy)
    x, y = segment.T  # segment xy
    inside = (x >= 0) & (y >= 0) & (x <= width) & (y <= height)
    x, y, = x[inside], y[inside]
    return np.array([x.min(), y.min(), x.max(), y.max()]) if any(x) else np.zeros((1, 4))  # xyxy


def segments2boxes(segments):
    # Convert segment labels to box labels, i.e. (cls, xy1, xy2, ...) to (cls, xywh)
    boxes = []
    for s in segments:
        x, y = s.T  # segment xy
        boxes.append([x.min(), y.min(), x.max(), y.max()])  # cls, xyxy
    return xyxy2xywh(np.array(boxes))  # cls, xywh


def resample_segments(segments, n=1000):
    # Up-sample an (n,2) segment
    for i, s in enumerate(segments):
        x = np.linspace(0, len(s) - 1, n)
        xp = np.arange(len(s))
        segments[i] = np.concatenate([np.interp(x, xp, s[:, i]) for i in range(2)]).reshape(2, -1).T  # segment xy
    return segments


def scale_coords(img1_shape, coords, img0_shape, ratio_pad=None):
    # Rescale coords (xyxy) from img1_shape to img0_shape
    if ratio_pad is None:  # calculate from img0_shape
        gain = min(img1_shape[0] / img0_shape[0], img1_shape[1] / img0_shape[1])  # gain  = old / new
        pad = (img1_shape[1] - img0_shape[1] * gain) / 2, (img1_shape[0] - img0_shape[0] * gain) / 2  # wh padding
    else:
        gain = ratio_pad[0][0]
        pad = ratio_pad[1]

    coords[:, [0, 2]] -= pad[0]  # x padding
    coords[:, [1, 3]] -= pad[1]  # y padding
    coords[:, :4] /= gain
    clip_coords(coords, img0_shape)
    return coords


def clip_coords(boxes, img_shape):
    # Clip bounding xyxy bounding boxes to image shape (height, width)
    boxes[:, 0].clamp_(0, img_shape[1])  # x1
    boxes[:, 1].clamp_(0, img_shape[0])  # y1
    boxes[:, 2].clamp_(0, img_shape[1])  # x2
    boxes[:, 3].clamp_(0, img_shape[0])  # y2


def bbox_iou(box1, box2, x1y1x2y2=True, GIoU=False, DIoU=False, CIoU=False, eps=1e-7):
    # Returns the IoU of box1 to box2. box1 is 4, box2 is nx4
    box2 = box2.T

    # Get the coordinates of bounding boxes
    if x1y1x2y2:  # x1, y1, x2, y2 = box1
        b1_x1, b1_y1, b1_x2, b1_y2 = box1[0], box1[1], box1[2], box1[3]
        b2_x1, b2_y1, b2_x2, b2_y2 = box2[0], box2[1], box2[2], box2[3]
    else:  # transform from xywh to xyxy
        b1_x1, b1_x2 = box1[0] - box1[2] / 2, box1[0] + box1[2] / 2
        b1_y1, b1_y2 = box1[1] - box1[3] / 2, box1[1] + box1[3] / 2
        b2_x1, b2_x2 = box2[0] - box2[2] / 2, box2[0] + box2[2] / 2
        b2_y1, b2_y2 = box2[1] - box2[3] / 2, box2[1] + box2[3] / 2

    # Intersection area
    inter = (torch.min(b1_x2, b2_x2) - torch.max(b1_x1, b2_x1)).clamp(0) * \
            (torch.min(b1_y2, b2_y2) - torch.max(b1_y1, b2_y1)).clamp(0)

    # Union Area
    w1, h1 = b1_x2 - b1_x1, b1_y2 - b1_y1 + eps
    w2, h2 = b2_x2 - b2_x1, b2_y2 - b2_y1 + eps
    union = w1 * h1 + w2 * h2 - inter + eps

    iou = inter / union
    if GIoU or DIoU or CIoU:
        cw = torch.max(b1_x2, b2_x2) - torch.min(b1_x1, b2_x1)  # convex (smallest enclosing box) width
        ch = torch.max(b1_y2, b2_y2) - torch.min(b1_y1, b2_y1)  # convex height
        if CIoU or DIoU:  # Distance or Complete IoU https://arxiv.org/abs/1911.08287v1
            c2 = cw ** 2 + ch ** 2 + eps  # convex diagonal squared
            rho2 = ((b2_x1 + b2_x2 - b1_x1 - b1_x2) ** 2 +
                    (b2_y1 + b2_y2 - b1_y1 - b1_y2) ** 2) / 4  # center distance squared
            if DIoU:
                return iou - rho2 / c2  # DIoU
            elif CIoU:  # https://github.com/Zzh-tju/DIoU-SSD-pytorch/blob/master/utils/box/box_utils.py#L47
                v = (4 / math.pi ** 2) * torch.pow(torch.atan(w2 / h2) - torch.atan(w1 / h1), 2)
                with torch.no_grad():
                    alpha = v / (v - iou + (1 + eps))
                return iou - (rho2 / c2 + v * alpha)  # CIoU
        else:  # GIoU https://arxiv.org/pdf/1902.09630.pdf
            c_area = cw * ch + eps  # convex area
            return iou - (c_area - union) / c_area  # GIoU
    else:
        return iou  # IoU


def box_iou(box1, box2):
    # https://github.com/pytorch/vision/blob/master/torchvision/ops/boxes.py
    """
    Return intersection-over-union (Jaccard index) of boxes.
    Both sets of boxes are expected to be in (x1, y1, x2, y2) format.
    Arguments:
        box1 (Tensor[N, 4])
        box2 (Tensor[M, 4])
    Returns:
        iou (Tensor[N, M]): the NxM matrix containing the pairwise
            IoU values for every element in boxes1 and boxes2
    """

    def box_area(box):
        # box = 4xn
        return (box[2] - box[0]) * (box[3] - box[1])

    area1 = box_area(box1.T)
    area2 = box_area(box2.T)

    # inter(N,M) = (rb(N,M,2) - lt(N,M,2)).clamp(0).prod(2)
    inter = (torch.min(box1[:, None, 2:], box2[:, 2:]) - torch.max(box1[:, None, :2], box2[:, :2])).clamp(0).prod(2)
    return inter / (area1[:, None] + area2 - inter)  # iou = inter / (area1 + area2 - inter)


def wh_iou(wh1, wh2):
    # Returns the nxm IoU matrix. wh1 is nx2, wh2 is mx2
    wh1 = wh1[:, None]  # [N,1,2]
    wh2 = wh2[None]  # [1,M,2]
    inter = torch.min(wh1, wh2).prod(2)  # [N,M]
    return inter / (wh1.prod(2) + wh2.prod(2) - inter)  # iou = inter / (area1 + area2 - inter)


def non_max_suppression(prediction, conf_thres=0.25, iou_thres=0.45, classes=None, agnostic=False, multi_label=False,
                        labels=(), max_det=300):
    """Runs Non-Maximum Suppression (NMS) on inference results

    Returns:
         list of detections, on (n,6) tensor per image [xyxy, conf, cls]
    """

    nc = prediction.shape[2] - 5  # number of classes
    xc = prediction[..., 4] > conf_thres  # candidates

    # Checks
    assert 0 <= conf_thres <= 1, f'Invalid Confidence threshold {conf_thres}, valid values are between 0.0 and 1.0'
    assert 0 <= iou_thres <= 1, f'Invalid IoU {iou_thres}, valid values are between 0.0 and 1.0'

    # Settings
    min_wh, max_wh = 2, 4096  # (pixels) minimum and maximum box width and height
    max_nms = 30000  # maximum number of boxes into torchvision.ops.nms()
    time_limit = 10.0  # seconds to quit after
    redundant = True  # require redundant detections
    multi_label &= nc > 1  # multiple labels per box (adds 0.5ms/img)
    merge = False  # use merge-NMS

    t = time.time()
    output = [torch.zeros((0, 6), device=prediction.device)] * prediction.shape[0]
    for xi, x in enumerate(prediction):  # image index, image inference
        # Apply constraints
        # x[((x[..., 2:4] < min_wh) | (x[..., 2:4] > max_wh)).any(1), 4] = 0  # width-height
        x = x[xc[xi]]  # confidence

        # Cat apriori labels if autolabelling
        if labels and len(labels[xi]):
            l = labels[xi]
            v = torch.zeros((len(l), nc + 5), device=x.device)
            v[:, :4] = l[:, 1:5]  # box
            v[:, 4] = 1.0  # conf
            v[range(len(l)), l[:, 0].long() + 5] = 1.0  # cls
            x = torch.cat((x, v), 0)

        # If none remain process next image
        if not x.shape[0]:
            continue

        # Compute conf
        x[:, 5:] *= x[:, 4:5]  # conf = obj_conf * cls_conf

        # Box (center x, center y, width, height) to (x1, y1, x2, y2)
        box = xywh2xyxy(x[:, :4])

        # Detections matrix nx6 (xyxy, conf, cls)
        if multi_label:
            i, j = (x[:, 5:] > conf_thres).nonzero(as_tuple=False).T
            x = torch.cat((box[i], x[i, j + 5, None], j[:, None].float()), 1)
        else:  # best class only
            conf, j = x[:, 5:].max(1, keepdim=True)
            x = torch.cat((box, conf, j.float()), 1)[conf.view(-1) > conf_thres]

        # Filter by class
        if classes is not None:
            x = x[(x[:, 5:6] == torch.tensor(classes, device=x.device)).any(1)]

        # Apply finite constraint
        # if not torch.isfinite(x).all():
        #     x = x[torch.isfinite(x).all(1)]

        # Check shape
        n = x.shape[0]  # number of boxes
        if not n:  # no boxes
            continue
        elif n > max_nms:  # excess boxes
            x = x[x[:, 4].argsort(descending=True)[:max_nms]]  # sort by confidence

        # Batched NMS
        c = x[:, 5:6] * (0 if agnostic else max_wh)  # classes
        boxes, scores = x[:, :4] + c, x[:, 4]  # boxes (offset by class), scores
        i = torchvision.ops.nms(boxes, scores, iou_thres)  # NMS
        if i.shape[0] > max_det:  # limit detections
            i = i[:max_det]
        if merge and (1 < n < 3E3):  # Merge NMS (boxes merged using weighted mean)
            # update boxes as boxes(i,4) = weights(i,n) * boxes(n,4)
            iou = box_iou(boxes[i], boxes) > iou_thres  # iou matrix
            weights = iou * scores[None]  # box weights
            x[i, :4] = torch.mm(weights, x[:, :4]).float() / weights.sum(1, keepdim=True)  # merged boxes
            if redundant:
                i = i[iou.sum(1) > 1]  # require redundancy

        output[xi] = x[i]
        if (time.time() - t) > time_limit:
            print(f'WARNING: NMS time limit {time_limit}s exceeded')
            break  # time limit exceeded

    return output


def strip_optimizer(f='best.pt', s=''):  # from utils.general import *; strip_optimizer()
    # Strip optimizer from 'f' to finalize training, optionally save as 's'
    x = torch.load(f, map_location=torch.device('cpu'))
    if x.get('ema'):
        x['model'] = x['ema']  # replace model with ema
    for k in 'optimizer', 'training_results', 'wandb_id', 'ema', 'updates':  # keys
        x[k] = None
    x['epoch'] = -1
    x['model'].half()  # to FP16
    for p in x['model'].parameters():
        p.requires_grad = False
    torch.save(x, s or f)
    mb = os.path.getsize(s or f) / 1E6  # filesize
    print(f"Optimizer stripped from {f},{(' saved as %s,' % s) if s else ''} {mb:.1f}MB")


def print_mutation(hyp, results, yaml_file='hyp_evolved.yaml', bucket=''):
    # Print mutation results to evolve.txt (for use with train.py --evolve)
    a = '%10s' * len(hyp) % tuple(hyp.keys())  # hyperparam keys
    b = '%10.3g' * len(hyp) % tuple(hyp.values())  # hyperparam values
    c = '%10.4g' * len(results) % results  # results (P, R, mAP@0.5, mAP@0.5:0.95, val_losses x 3)
    print('\n%s\n%s\nEvolved fitness: %s\n' % (a, b, c))

    if bucket:
        url = 'gs://%s/evolve.txt' % bucket
        if gsutil_getsize(url) > (os.path.getsize('evolve.txt') if os.path.exists('evolve.txt') else 0):
            os.system('gsutil cp %s .' % url)  # download evolve.txt if larger than local

    with open('evolve.txt', 'a') as f:  # append result
        f.write(c + b + '\n')
    x = np.unique(np.loadtxt('evolve.txt', ndmin=2), axis=0)  # load unique rows
    x = x[np.argsort(-fitness(x))]  # sort
    np.savetxt('evolve.txt', x, '%10.3g')  # save sort by fitness

    # Save yaml
    for i, k in enumerate(hyp.keys()):
        hyp[k] = float(x[0, i + 7])
    with open(yaml_file, 'w') as f:
        results = tuple(x[0, :7])
        c = '%10.4g' * len(results) % results  # results (P, R, mAP@0.5, mAP@0.5:0.95, val_losses x 3)
        f.write('# Hyperparameter Evolution Results\n# Generations: %g\n# Metrics: ' % len(x) + c + '\n\n')
        yaml.safe_dump(hyp, f, sort_keys=False)

    if bucket:
        os.system('gsutil cp evolve.txt %s gs://%s' % (yaml_file, bucket))  # upload


def apply_classifier(x, model, img, im0):
    # Apply a second stage classifier to yolo outputs
    im0 = [im0] if isinstance(im0, np.ndarray) else im0
    for i, d in enumerate(x):  # per image
        if d is not None and len(d):
            d = d.clone()

            # Reshape and pad cutouts
            b = xyxy2xywh(d[:, :4])  # boxes
            b[:, 2:] = b[:, 2:].max(1)[0].unsqueeze(1)  # rectangle to square
            b[:, 2:] = b[:, 2:] * 1.3 + 30  # pad
            d[:, :4] = xywh2xyxy(b).long()

            # Rescale boxes from img_size to im0 size
            scale_coords(img.shape[2:], d[:, :4], im0[i].shape)

            # Classes
            pred_cls1 = d[:, 5].long()
            ims = []
            for j, a in enumerate(d):  # per item
                cutout = im0[i][int(a[1]):int(a[3]), int(a[0]):int(a[2])]
                im = cv2.resize(cutout, (224, 224))  # BGR
                # cv2.imwrite('test%i.jpg' % j, cutout)

                im = im[:, :, ::-1].transpose(2, 0, 1)  # BGR to RGB, to 3x416x416
                im = np.ascontiguousarray(im, dtype=np.float32)  # uint8 to float32
                im /= 255.0  # 0 - 255 to 0.0 - 1.0
                ims.append(im)

            pred_cls2 = model(torch.Tensor(ims).to(d.device)).argmax(1)  # classifier prediction
            x[i] = x[i][pred_cls1 == pred_cls2]  # retain matching class detections

    return x


def save_one_box(xyxy, im, file='image.jpg', gain=1.02, pad=10, square=False, BGR=False, save=True):
    # Save image crop as {file} with crop size multiple {gain} and {pad} pixels. Save and/or return crop
    xyxy = torch.tensor(xyxy).view(-1, 4)
    b = xyxy2xywh(xyxy)  # boxes
    if square:
        b[:, 2:] = b[:, 2:].max(1)[0].unsqueeze(1)  # attempt rectangle to square
    b[:, 2:] = b[:, 2:] * gain + pad  # box wh * gain + pad
    xyxy = xywh2xyxy(b).long()
    clip_coords(xyxy, im.shape)
    crop = im[int(xyxy[0, 1]):int(xyxy[0, 3]), int(xyxy[0, 0]):int(xyxy[0, 2]), ::(1 if BGR else -1)]
    if save:
        cv2.imwrite(str(increment_path(file, mkdir=True).with_suffix('.jpg')), crop)
    return crop


def increment_path(path, exist_ok=False, sep='', mkdir=False):
    # Increment file or directory path, i.e. runs/exp --> runs/exp{sep}2, runs/exp{sep}3, ... etc.
    path = Path(path)  # os-agnostic
    if path.exists() and not exist_ok:
        suffix = path.suffix
        path = path.with_suffix('')
        dirs = glob.glob(f"{path}{sep}*")  # similar paths
        matches = [re.search(rf"%s{sep}(\d+)" % path.stem, d) for d in dirs]
        i = [int(m.groups()[0]) for m in matches if m]  # indices
        n = max(i) + 1 if i else 2  # increment number
        path = Path(f"{path}{sep}{n}{suffix}")  # update path
    dir = path if path.suffix == '' else path.parent  # directory
    if not dir.exists() and mkdir:
        dir.mkdir(parents=True, exist_ok=True)  # make directory
    return path