car-detection-bayes/utils/datasets.py

import glob
import math
import os
import random

import cv2
import numpy as np
import torch
from torch.utils.data import Dataset

from utils.utils import xyxy2xywh


class LoadImages:  # for inference
    def __init__(self, path, img_size=416):
        if os.path.isdir(path):
            image_format = ['.jpg', '.jpeg', '.png', '.tif']
            self.files = sorted(glob.glob('%s/*.*' % path))
            self.files = list(filter(lambda x: os.path.splitext(x)[1].lower() in image_format, self.files))
        elif os.path.isfile(path):
            self.files = [path]

        self.nF = len(self.files)  # number of image files
        self.height = img_size

        assert self.nF > 0, 'No images found in ' + path

    def __iter__(self):
        self.count = -1
        return self

    def __next__(self):
        self.count += 1
        if self.count == self.nF:
            raise StopIteration
        img_path = self.files[self.count]

        # Read image
        img0 = cv2.imread(img_path)  # BGR
        assert img0 is not None, 'File Not Found ' + img_path

        # Padded resize
        img, _, _, _ = letterbox(img0, height=self.height)

        # Normalize RGB
        img = img[:, :, ::-1].transpose(2, 0, 1)  # BGR to RGB
        img = np.ascontiguousarray(img, dtype=np.float32)  # uint8 to float32
        img /= 255.0  # 0 - 255 to 0.0 - 1.0

        # cv2.imwrite(img_path + '.letterbox.jpg', 255 * img.transpose((1, 2, 0))[:, :, ::-1])  # save letterbox image
        return img_path, img, img0

    def __len__(self):
        return self.nF  # number of files


class LoadWebcam:  # for inference
    def __init__(self, img_size=416):
        self.cam = cv2.VideoCapture(0)
        self.height = img_size

    def __iter__(self):
        self.count = -1
        return self

    def __next__(self):
        self.count += 1
        if cv2.waitKey(1) == 27:  # esc to quit
            cv2.destroyAllWindows()
            raise StopIteration

        # Read image
        ret_val, img0 = self.cam.read()
        assert ret_val, 'Webcam Error'
        img_path = 'webcam_%g.jpg' % self.count
        img0 = cv2.flip(img0, 1)  # flip left-right

        # Padded resize
        img, _, _, _ = letterbox(img0, height=self.height)

        # Normalize RGB
        img = img[:, :, ::-1].transpose(2, 0, 1)  # BGR to RGB
        img = np.ascontiguousarray(img, dtype=np.float32)  # uint8 to float32
        img /= 255.0  # 0 - 255 to 0.0 - 1.0

        return img_path, img, img0

    def __len__(self):
        return 0


class LoadImagesAndLabels(Dataset):  # for training/testing
    def __init__(self, path, img_size=416, augment=False):
        with open(path, 'r') as file:
            self.img_files = file.read().splitlines()
            self.img_files = list(filter(lambda x: len(x) > 0, self.img_files))
        assert len(self.img_files) > 0, 'No images found in %s' % path
        self.img_size = img_size
        self.augment = augment
        self.label_files = [x.replace('images', 'labels').replace('.png', '.txt').replace('.jpg', '.txt')
                            for x in self.img_files]

    def __len__(self):
        return len(self.img_files)

    def __getitem__(self, index):
        img_path = self.img_files[index]
        label_path = self.label_files[index]

        img = cv2.imread(img_path)  # BGR
        assert img is not None, 'File Not Found ' + img_path

        augment_hsv = True
        if self.augment and augment_hsv:
            # SV augmentation by 50%
            fraction = 0.50
            img_hsv = cv2.cvtColor(img, cv2.COLOR_BGR2HSV)
            S = img_hsv[:, :, 1].astype(np.float32)
            V = img_hsv[:, :, 2].astype(np.float32)

            a = (random.random() * 2 - 1) * fraction + 1
            S *= a
            if a > 1:
                np.clip(S, a_min=0, a_max=255, out=S)

            a = (random.random() * 2 - 1) * fraction + 1
            V *= a
            if a > 1:
                np.clip(V, a_min=0, a_max=255, out=V)

            img_hsv[:, :, 1] = S.astype(np.uint8)
            img_hsv[:, :, 2] = V.astype(np.uint8)
            cv2.cvtColor(img_hsv, cv2.COLOR_HSV2BGR, dst=img)

        h, w, _ = img.shape
        img, ratio, padw, padh = letterbox(img, height=self.img_size)

        # Load labels
        if os.path.isfile(label_path):
            # labels0 = np.loadtxt(label_path, dtype=np.float32).reshape(-1, 5)  # SLOWER
            with open(label_path, 'r') as file:
                lines = file.read().splitlines()
                labels0 = np.array([x.split() for x in lines], dtype=np.float32)
            # If label file is empty
            if labels0.size is 0:
                labels = np.array([])
            else:
                # Normalized xywh to pixel xyxy format
                labels = labels0.copy()
                labels[:, 1] = ratio * w * (labels0[:, 1] - labels0[:, 3] / 2) + padw
                labels[:, 2] = ratio * h * (labels0[:, 2] - labels0[:, 4] / 2) + padh
                labels[:, 3] = ratio * w * (labels0[:, 1] + labels0[:, 3] / 2) + padw
                labels[:, 4] = ratio * h * (labels0[:, 2] + labels0[:, 4] / 2) + padh
        else:
            labels = np.array([])

        # Augment image and labels
        if self.augment:
            img, labels, M = random_affine(img, labels, degrees=(-5, 5), translate=(0.10, 0.10), scale=(0.90, 1.10))

        nL = len(labels)
        if nL > 0:
            # convert xyxy to xywh
            labels[:, 1:5] = xyxy2xywh(labels[:, 1:5].copy()) / self.img_size

        if self.augment:
            # random left-right flip
            lr_flip = True
            if lr_flip & (random.random() > 0.5):
                img = np.fliplr(img)
                if nL > 0:
                    labels[:, 1] = 1 - labels[:, 1]

            # random up-down flip
            ud_flip = False
            if ud_flip & (random.random() > 0.5):
                img = np.flipud(img)
                if nL > 0:
                    labels[:, 2] = 1 - labels[:, 2]

        labels_out = np.zeros((100, 6), dtype=np.float32)
        if nL > 0:
            labels_out[:nL, 1:] = labels  # max 100 labels per image

        # Normalize
        img = img[:, :, ::-1].transpose(2, 0, 1)  # list to np.array and BGR to RGB
        img = np.ascontiguousarray(img, dtype=np.float32)  # uint8 to float32
        img /= 255.0  # 0 - 255 to 0.0 - 1.0

        return torch.from_numpy(img), torch.from_numpy(labels_out), img_path, (h, w)


def letterbox(img, height=416, color=(127.5, 127.5, 127.5)):  # resize a rectangular image to a padded square
    shape = img.shape[:2]  # shape = [height, width]
    ratio = float(height) / max(shape)  # ratio  = old / new
    new_shape = (round(shape[1] * ratio), round(shape[0] * ratio))
    dw = (height - new_shape[0]) / 2  # width padding
    dh = (height - new_shape[1]) / 2  # height padding
    top, bottom = round(dh - 0.1), round(dh + 0.1)
    left, right = round(dw - 0.1), round(dw + 0.1)
    img = cv2.resize(img, new_shape, interpolation=cv2.INTER_AREA)  # resized, no border
    img = cv2.copyMakeBorder(img, top, bottom, left, right, cv2.BORDER_CONSTANT, value=color)  # padded square
    return img, ratio, dw, dh


def random_affine(img, targets=None, degrees=(-10, 10), translate=(.1, .1), scale=(.9, 1.1), shear=(-2, 2),
                  borderValue=(127.5, 127.5, 127.5)):
    # torchvision.transforms.RandomAffine(degrees=(-10, 10), translate=(.1, .1), scale=(.9, 1.1), shear=(-10, 10))
    # https://medium.com/uruvideo/dataset-augmentation-with-random-homographies-a8f4b44830d4

    border = 0  # width of added border (optional)
    height = max(img.shape[0], img.shape[1]) + border * 2

    # Rotation and Scale
    R = np.eye(3)
    a = random.random() * (degrees[1] - degrees[0]) + degrees[0]
    # a += random.choice([-180, -90, 0, 90])  # 90deg rotations added to small rotations
    s = random.random() * (scale[1] - scale[0]) + scale[0]
    R[:2] = cv2.getRotationMatrix2D(angle=a, center=(img.shape[1] / 2, img.shape[0] / 2), scale=s)

    # Translation
    T = np.eye(3)
    T[0, 2] = (random.random() * 2 - 1) * translate[0] * img.shape[0] + border  # x translation (pixels)
    T[1, 2] = (random.random() * 2 - 1) * translate[1] * img.shape[1] + border  # y translation (pixels)

    # Shear
    S = np.eye(3)
    S[0, 1] = math.tan((random.random() * (shear[1] - shear[0]) + shear[0]) * math.pi / 180)  # x shear (deg)
    S[1, 0] = math.tan((random.random() * (shear[1] - shear[0]) + shear[0]) * math.pi / 180)  # y shear (deg)

    M = S @ T @ R  # Combined rotation matrix. ORDER IS IMPORTANT HERE!!
    imw = cv2.warpPerspective(img, M, dsize=(height, height), flags=cv2.INTER_LINEAR,
                              borderValue=borderValue)  # BGR order borderValue

    # Return warped points also
    if targets is not None:
        if len(targets) > 0:
            n = targets.shape[0]
            points = targets[:, 1:5].copy()
            area0 = (points[:, 2] - points[:, 0]) * (points[:, 3] - points[:, 1])

            # warp points
            xy = np.ones((n * 4, 3))
            xy[:, :2] = points[:, [0, 1, 2, 3, 0, 3, 2, 1]].reshape(n * 4, 2)  # x1y1, x2y2, x1y2, x2y1
            xy = (xy @ M.T)[:, :2].reshape(n, 8)

            # create new boxes
            x = xy[:, [0, 2, 4, 6]]
            y = xy[:, [1, 3, 5, 7]]
            xy = np.concatenate((x.min(1), y.min(1), x.max(1), y.max(1))).reshape(4, n).T

            # apply angle-based reduction
            radians = a * math.pi / 180
            reduction = max(abs(math.sin(radians)), abs(math.cos(radians))) ** 0.5
            x = (xy[:, 2] + xy[:, 0]) / 2
            y = (xy[:, 3] + xy[:, 1]) / 2
            w = (xy[:, 2] - xy[:, 0]) * reduction
            h = (xy[:, 3] - xy[:, 1]) * reduction
            xy = np.concatenate((x - w / 2, y - h / 2, x + w / 2, y + h / 2)).reshape(4, n).T

            # reject warped points outside of image
            np.clip(xy, 0, height, out=xy)
            w = xy[:, 2] - xy[:, 0]
            h = xy[:, 3] - xy[:, 1]
            area = w * h
            ar = np.maximum(w / (h + 1e-16), h / (w + 1e-16))
            i = (w > 4) & (h > 4) & (area / (area0 + 1e-16) > 0.1) & (ar < 10)

            targets = targets[i]
            targets[:, 1:5] = xy[i]

        return imw, targets, M
    else:
        return imw


def convert_tif2bmp(p='../xview/val_images_bmp'):
    import glob
    import cv2
    files = sorted(glob.glob('%s/*.tif' % p))
    for i, f in enumerate(files):
        print('%g/%g' % (i + 1, len(files)))
        cv2.imwrite(f.replace('.tif', '.bmp'), cv2.imread(f))
        os.system('rm -rf ' + f)