import glob
import random
import cv2
import matplotlib
import matplotlib.pyplot as plt
import numpy as np
import torch
import torch.nn as nn
from utils import torch_utils
matplotlib.rc('font', **{'size': 12})
# Set printoptions
torch.set_printoptions(linewidth=1320, precision=5, profile='long')
np.set_printoptions(linewidth=320, formatter={'float_kind': '{:11.5g}'.format}) # format short g, %precision=5
# Prevent OpenCV from multithreading (to use PyTorch DataLoader)
cv2.setNumThreads(0)
def float3(x): # format floats to 3 decimals
return float(format(x, '.3f'))
def init_seeds(seed=0):
random.seed(seed)
np.random.seed(seed)
torch_utils.init_seeds(seed=seed)
def load_classes(path):
# Loads class labels at 'path'
fp = open(path, 'r')
names = fp.read().split('\n')
return list(filter(None, names)) # filter removes empty strings (such as last line)
def model_info(model):
# Plots a line-by-line description of a PyTorch model
n_p = sum(x.numel() for x in model.parameters()) # number parameters
n_g = sum(x.numel() for x in model.parameters() if x.requires_grad) # number gradients
print('\n%5s %40s %9s %12s %20s %10s %10s' % ('layer', 'name', 'gradient', 'parameters', 'shape', 'mu', 'sigma'))
for i, (name, p) in enumerate(model.named_parameters()):
name = name.replace('module_list.', '')
print('%5g %40s %9s %12g %20s %10.3g %10.3g' % (
i, name, p.requires_grad, p.numel(), list(p.shape), p.mean(), p.std()))
print('Model Summary: %g layers, %g parameters, %g gradients' % (i + 1, n_p, n_g))
def coco_class_weights(): # frequency of each class in coco train2014
weights = 1 / torch.FloatTensor(
[187437, 4955, 30920, 6033, 3838, 4332, 3160, 7051, 7677, 9167, 1316, 1372, 833, 6757, 7355, 3302, 3776, 4671,
6769, 5706, 3908, 903, 3686, 3596, 6200, 7920, 8779, 4505, 4272, 1862, 4698, 1962, 4403, 6659, 2402, 2689,
4012, 4175, 3411, 17048, 5637, 14553, 3923, 5539, 4289, 10084, 7018, 4314, 3099, 4638, 4939, 5543, 2038, 4004,
5053, 4578, 27292, 4113, 5931, 2905, 11174, 2873, 4036, 3415, 1517, 4122, 1980, 4464, 1190, 2302, 156, 3933,
1877, 17630, 4337, 4624, 1075, 3468, 135, 1380])
weights /= weights.sum()
return 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')
# x = [list(a[i] == b).index(True) + 1 for i in range(80)] # darknet to coco
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 weights_init_normal(m):
classname = m.__class__.__name__
if classname.find('Conv') != -1:
torch.nn.init.normal_(m.weight.data, 0.0, 0.03)
elif classname.find('BatchNorm2d') != -1:
torch.nn.init.normal_(m.weight.data, 1.0, 0.03)
torch.nn.init.constant_(m.bias.data, 0.0)
def xyxy2xywh(x):
# Convert bounding box format from [x1, y1, x2, y2] to [x, y, w, h]
y = torch.zeros_like(x) if isinstance(x, torch.Tensor) else np.zeros_like(x)
y[:, 0] = (x[:, 0] + x[:, 2]) / 2
y[:, 1] = (x[:, 1] + x[:, 3]) / 2
y[:, 2] = x[:, 2] - x[:, 0]
y[:, 3] = x[:, 3] - x[:, 1]
return y
def xywh2xyxy(x):
# Convert bounding box format from [x, y, w, h] to [x1, y1, x2, y2]
y = torch.zeros_like(x) if isinstance(x, torch.Tensor) else np.zeros_like(x)
y[:, 0] = x[:, 0] - x[:, 2] / 2
y[:, 1] = x[:, 1] - x[:, 3] / 2
y[:, 2] = x[:, 0] + x[:, 2] / 2
y[:, 3] = x[:, 1] + x[:, 3] / 2
return y
def scale_coords(img_size, coords, img0_shape):
# Rescale x1, y1, x2, y2 from 416 to image size
gain = float(img_size) / max(img0_shape) # gain = old / new
pad_x = (img_size - img0_shape[1] * gain) / 2 # width padding
pad_y = (img_size - img0_shape[0] * gain) / 2 # height padding
coords[:, [0, 2]] -= pad_x
coords[:, [1, 3]] -= pad_y
coords[:, :4] /= gain
coords[:, :4] = torch.clamp(coords[:, :4], min=0)
return coords
def ap_per_class(tp, conf, pred_cls, target_cls):
""" Compute the average precision, given the recall and precision curves.
Source: https://github.com/rafaelpadilla/Object-Detection-Metrics.
# Arguments
tp: True positives (list).
conf: Objectness value from 0-1 (list).
pred_cls: Predicted object classes (list).
target_cls: True object classes (list).
# Returns
The average precision as computed in py-faster-rcnn.
"""
# Sort by objectness
i = np.argsort(-conf)
tp, conf, pred_cls = tp[i], conf[i], pred_cls[i]
# Find unique classes
unique_classes = np.unique(target_cls)
# Create Precision-Recall curve and compute AP for each class
ap, p, r = [], [], []
for c in unique_classes:
i = pred_cls == c
n_gt = (target_cls == c).sum() # Number of ground truth objects
n_p = i.sum() # Number of predicted objects
if n_p == 0 and n_gt == 0:
continue
elif n_p == 0 or n_gt == 0:
ap.append(0)
r.append(0)
p.append(0)
else:
# Accumulate FPs and TPs
fpc = (1 - tp[i]).cumsum()
tpc = (tp[i]).cumsum()
# Recall
recall_curve = tpc / (n_gt + 1e-16)
r.append(recall_curve[-1])
# Precision
precision_curve = tpc / (tpc + fpc)
p.append(precision_curve[-1])
# AP from recall-precision curve
ap.append(compute_ap(recall_curve, precision_curve))
# Plot
# plt.plot(recall_curve, precision_curve)
# Compute F1 score (harmonic mean of precision and recall)
p, r, ap = np.array(p), np.array(r), np.array(ap)
f1 = 2 * p * r / (p + r + 1e-16)
return p, r, ap, f1, unique_classes.astype('int32')
def compute_ap(recall, precision):
""" Compute the average precision, given the recall and precision curves.
Source: https://github.com/rbgirshick/py-faster-rcnn.
# Arguments
recall: The recall curve (list).
precision: The precision curve (list).
# Returns
The average precision as computed in py-faster-rcnn.
"""
# correct AP calculation
# first append sentinel values at the end
mrec = np.concatenate(([0.], recall, [1.]))
mpre = np.concatenate(([0.], precision, [0.]))
# compute the precision envelope
for i in range(mpre.size - 1, 0, -1):
mpre[i - 1] = np.maximum(mpre[i - 1], mpre[i])
# to calculate area under PR curve, look for points
# where X axis (recall) changes value
i = np.where(mrec[1:] != mrec[:-1])[0]
# and sum (\Delta recall) * prec
ap = np.sum((mrec[i + 1] - mrec[i]) * mpre[i + 1])
return ap
def bbox_iou(box1, box2, x1y1x2y2=True):
# 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:
# x, y, w, h = box1
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_area = (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
union_area = ((b1_x2 - b1_x1) * (b1_y2 - b1_y1) + 1e-16) + \
(b2_x2 - b2_x1) * (b2_y2 - b2_y1) - inter_area
return inter_area / union_area # iou
def wh_iou(box1, box2):
# Returns the IoU of wh1 to wh2. wh1 is 2, wh2 is nx2
box2 = box2.t()
# w, h = box1
w1, h1 = box1[0], box1[1]
w2, h2 = box2[0], box2[1]
# Intersection area
inter_area = torch.min(w1, w2) * torch.min(h1, h2)
# Union Area
union_area = (w1 * h1 + 1e-16) + w2 * h2 - inter_area
return inter_area / union_area # iou
def compute_loss(p, targets, model): # predictions, targets, model
ft = torch.cuda.FloatTensor if p[0].is_cuda else torch.Tensor
lxy, lwh, lcls, lconf = ft([0]), ft([0]), ft([0]), ft([0])
txy, twh, tcls, indices = build_targets(model, targets)
# Define criteria
MSE = nn.MSELoss()
CE = nn.CrossEntropyLoss()
BCE = nn.BCEWithLogitsLoss()
# Compute losses
h = model.hyp # hyperparameters
bs = p[0].shape[0] # batch size
k = h['k'] * bs # loss gain
for i, pi0 in enumerate(p): # layer i predictions, i
b, a, gj, gi = indices[i] # image, anchor, gridx, gridy
tconf = torch.zeros_like(pi0[..., 0]) # conf
# Compute losses
if len(b): # number of targets
pi = pi0[b, a, gj, gi] # predictions closest to anchors
tconf[b, a, gj, gi] = 1 # conf
# pi[..., 2:4] = torch.sigmoid(pi[..., 2:4]) # wh power loss (uncomment)
lxy += (k * h['xy']) * MSE(torch.sigmoid(pi[..., 0:2]), txy[i]) # xy loss
lwh += (k * h['wh']) * MSE(pi[..., 2:4], twh[i]) # wh yolo loss
lcls += (k * h['cls']) * CE(pi[..., 5:], tcls[i]) # class_conf loss
# pos_weight = ft([gp[i] / min(gp) * 4.])
# BCE = nn.BCEWithLogitsLoss(pos_weight=pos_weight)
lconf += (k * h['conf']) * BCE(pi0[..., 4], tconf) # obj_conf loss
loss = lxy + lwh + lconf + lcls
return loss, torch.cat((lxy, lwh, lconf, lcls, loss)).detach()
def build_targets(model, targets):
# targets = [image, class, x, y, w, h]
iou_thres = model.hyp['iou_t'] # hyperparameter
if type(model) in (nn.parallel.DataParallel, nn.parallel.DistributedDataParallel):
model = model.module
nt = len(targets)
txy, twh, tcls, indices = [], [], [], []
for i in model.yolo_layers:
layer = model.module_list[i][0]
# iou of targets-anchors
t, a = targets, []
gwh = targets[:, 4:6] * layer.nG
if nt:
iou = [wh_iou(x, gwh) for x in layer.anchor_vec]
iou, a = torch.stack(iou, 0).max(0) # best iou and anchor
# reject below threshold ious (OPTIONAL, increases P, lowers R)
reject = True
if reject:
j = iou > iou_thres
t, a, gwh = targets[j], a[j], gwh[j]
# Indices
b, c = t[:, :2].long().t() # target image, class
gxy = t[:, 2:4] * layer.nG
gi, gj = gxy.long().t() # grid_i, grid_j
indices.append((b, a, gj, gi))
# XY coordinates
txy.append(gxy - gxy.floor())
# Width and height
twh.append(torch.log(gwh / layer.anchor_vec[a])) # wh yolo method
# twh.append((gwh / layer.anchor_vec[a]) ** (1 / 3) / 2) # wh power method
# Class
tcls.append(c)
if c.shape[0]:
assert c.max() <= layer.nC, 'Target classes exceed model classes'
return txy, twh, tcls, indices
def non_max_suppression(prediction, conf_thres=0.5, nms_thres=0.5):
"""
Removes detections with lower object confidence score than 'conf_thres'
Non-Maximum Suppression to further filter detections.
Returns detections with shape:
(x1, y1, x2, y2, object_conf, class_conf, class)
"""
min_wh = 2 # (pixels) minimum box width and height
output = [None] * len(prediction)
for image_i, pred in enumerate(prediction):
# Experiment: Prior class size rejection
# x, y, w, h = pred[:, 0], pred[:, 1], pred[:, 2], pred[:, 3]
# a = w * h # area
# ar = w / (h + 1e-16) # aspect ratio
# n = len(w)
# log_w, log_h, log_a, log_ar = torch.log(w), torch.log(h), torch.log(a), torch.log(ar)
# shape_likelihood = np.zeros((n, 60), dtype=np.float32)
# x = np.concatenate((log_w.reshape(-1, 1), log_h.reshape(-1, 1)), 1)
# from scipy.stats import multivariate_normal
# for c in range(60):
# shape_likelihood[:, c] =
# multivariate_normal.pdf(x, mean=mat['class_mu'][c, :2], cov=mat['class_cov'][c, :2, :2])
# Multiply conf by class conf to get combined confidence
class_conf, class_pred = pred[:, 5:].max(1)
pred[:, 4] *= class_conf
# Select only suitable predictions
i = (pred[:, 4] > conf_thres) & (pred[:, 2:4] > min_wh).all(1) & (torch.isnan(pred).any(1) == 0)
pred = pred[i]
# If none are remaining => process next image
if len(pred) == 0:
continue
# Select predicted classes
class_conf = class_conf[i]
class_pred = class_pred[i].unsqueeze(1).float()
# Box (center x, center y, width, height) to (x1, y1, x2, y2)
pred[:, :4] = xywh2xyxy(pred[:, :4])
# pred[:, 4] *= class_conf # improves mAP from 0.549 to 0.551
# Detections ordered as (x1y1x2y2, obj_conf, class_conf, class_pred)
pred = torch.cat((pred[:, :5], class_conf.unsqueeze(1), class_pred), 1)
# Get detections sorted by decreasing confidence scores
pred = pred[(-pred[:, 4]).argsort()]
det_max = []
nms_style = 'MERGE' # 'OR' (default), 'AND', 'MERGE' (experimental)
for c in pred[:, -1].unique():
dc = pred[pred[:, -1] == c] # select class c
dc = dc[:min(len(dc), 100)] # limit to first 100 boxes: https://github.com/ultralytics/yolov3/issues/117
# No NMS required if only 1 prediction
if len(dc) == 1:
det_max.append(dc)
continue
# Non-maximum suppression
if nms_style == 'OR': # default
# METHOD1
# ind = list(range(len(dc)))
# while len(ind):
# j = ind[0]
# det_max.append(dc[j:j + 1]) # save highest conf detection
# reject = (bbox_iou(dc[j], dc[ind]) > nms_thres).nonzero()
# [ind.pop(i) for i in reversed(reject)]
# METHOD2
while dc.shape[0]:
det_max.append(dc[:1]) # save highest conf detection
if len(dc) == 1: # Stop if we're at the last detection
break
iou = bbox_iou(dc[0], dc[1:]) # iou with other boxes
dc = dc[1:][iou < nms_thres] # remove ious > threshold
elif nms_style == 'AND': # requires overlap, single boxes erased
while len(dc) > 1:
iou = bbox_iou(dc[0], dc[1:]) # iou with other boxes
if iou.max() > 0.5:
det_max.append(dc[:1])
dc = dc[1:][iou < nms_thres] # remove ious > threshold
elif nms_style == 'MERGE': # weighted mixture box
while len(dc):
if len(dc) == 1:
det_max.append(dc)
break
i = bbox_iou(dc[0], dc) > nms_thres # iou with other boxes
weights = dc[i, 4:5]
dc[0, :4] = (weights * dc[i, :4]).sum(0) / weights.sum()
det_max.append(dc[:1])
dc = dc[i == 0]
if len(det_max):
det_max = torch.cat(det_max) # concatenate
output[image_i] = det_max[(-det_max[:, 4]).argsort()] # sort
return output
def get_yolo_layers(model):
bool_vec = [x['type'] == 'yolo' for x in model.module_defs]
return [i for i, x in enumerate(bool_vec) if x] # [82, 94, 106] for yolov3
def strip_optimizer_from_checkpoint(filename='weights/best.pt'):
# Strip optimizer from *.pt files for lighter files (reduced by 2/3 size)
a = torch.load(filename, map_location='cpu')
a['optimizer'] = []
torch.save(a, filename.replace('.pt', '_lite.pt'))
def coco_class_count(path='../coco/labels/train2014/'):
# Histogram of occurrences per class
nC = 80 # number classes
x = np.zeros(nC, dtype='int32')
files = sorted(glob.glob('%s/*.*' % path))
for i, file in enumerate(files):
labels = np.loadtxt(file, dtype=np.float32).reshape(-1, 5)
x += np.bincount(labels[:, 0].astype('int32'), minlength=nC)
print(i, len(files))
def coco_only_people(path='../coco/labels/val2014/'):
# Find images with only people
files = sorted(glob.glob('%s/*.*' % path))
for i, file in enumerate(files):
labels = np.loadtxt(file, dtype=np.float32).reshape(-1, 5)
if all(labels[:, 0] == 0):
print(labels.shape[0], file)
# Plotting functions ---------------------------------------------------------------------------------------------------
def plot_one_box(x, img, color=None, label=None, line_thickness=None):
# Plots one bounding box on image img
tl = line_thickness or round(0.002 * max(img.shape[0:2])) + 1 # line thickness
color = color or [random.randint(0, 255) for _ in range(3)]
c1, c2 = (int(x[0]), int(x[1])), (int(x[2]), int(x[3]))
cv2.rectangle(img, c1, c2, color, thickness=tl)
if label:
tf = max(tl - 1, 1) # font thickness
t_size = cv2.getTextSize(label, 0, fontScale=tl / 3, thickness=tf)[0]
c2 = c1[0] + t_size[0], c1[1] - t_size[1] - 3
cv2.rectangle(img, c1, c2, color, -1) # filled
cv2.putText(img, label, (c1[0], c1[1] - 2), 0, tl / 3, [225, 255, 255], thickness=tf, lineType=cv2.LINE_AA)
def plot_wh_methods(): # from utils.utils import *; plot_wh_methods()
# Compares the two methods for width-height anchor multiplication
# https://github.com/ultralytics/yolov3/issues/168
x = np.arange(-4.0, 4.0, .1)
ya = np.exp(x)
yb = torch.sigmoid(torch.from_numpy(x)).numpy() * 2
fig = plt.figure(figsize=(6, 3), dpi=150)
plt.plot(x, ya, '.-', label='yolo method')
plt.plot(x, yb ** 2, '.-', label='^2 power method')
plt.plot(x, yb ** 2.5, '.-', label='^2.5 power method')
plt.xlim(left=-4, right=4)
plt.ylim(bottom=0, top=6)
plt.xlabel('input')
plt.ylabel('output')
plt.legend()
fig.tight_layout()
fig.savefig('comparison.png', dpi=300)
def plot_images(imgs, targets, fname='images.jpg'):
# Plots training images overlaid with targets
imgs = imgs.cpu().numpy()
targets = targets.cpu().numpy()
fig = plt.figure(figsize=(10, 10))
img_size = imgs.shape[3]
bs = imgs.shape[0] # batch size
sp = np.ceil(bs ** 0.5) # subplots
for i in range(bs):
boxes = xywh2xyxy(targets[targets[:, 0] == i, 2:6]).T * img_size
plt.subplot(sp, sp, i + 1).imshow(imgs[i].transpose(1, 2, 0))
plt.plot(boxes[[0, 2, 2, 0, 0]], boxes[[1, 1, 3, 3, 1]], '.-')
plt.axis('off')
fig.tight_layout()
fig.savefig(fname, dpi=300)
plt.close()
def plot_results(start=0, stop=0): # from utils.utils import *; plot_results()
# Plot training results files 'results*.txt'
# import os; os.system('wget https://storage.googleapis.com/ultralytics/yolov3/results_v3.txt')
fig = plt.figure(figsize=(14, 7))
s = ['X + Y', 'Width + Height', 'Confidence', 'Classification', 'Train Loss', 'Precision', 'Recall', 'mAP', 'F1',
'Test Loss']
for f in sorted(glob.glob('results*.txt') + glob.glob('../../Downloads/results*.txt')):
results = np.loadtxt(f, usecols=[2, 3, 4, 5, 6, 9, 10, 11, 12, 13]).T
n = results.shape[1] # number of rows
x = range(start, min(stop, n) if stop else n)
for i in range(10):
plt.subplot(2, 5, i + 1)
plt.plot(x, results[i, x], marker='.', label=f.replace('.txt', ''))
plt.title(s[i])
if i == 0:
plt.legend()
fig.tight_layout()
fig.savefig('results.png', dpi=300)