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Rajeev Rao d7baf010e4 TensorRT OSS 21.02 release
Signed-off-by: Rajeev Rao <rajeevrao@nvidia.com>
2021-02-05 14:22:04 -08:00

246 lines
8.8 KiB
Python

#
# Copyright (c) 2021, NVIDIA CORPORATION. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
# VOC mAP computation, based on https://github.com/amdegroot/ssd.pytorch
import os
import sys
import pickle
import numpy as np
if sys.version_info[0] == 2:
import xml.etree.cElementTree as ET
else:
import xml.etree.ElementTree as ET
import utils.voc as voc_utils
from utils.paths import PATHS
def parse_voc_annotation_xml(voc_annotiotion_xml):
"""Parse VOC annotation XML file.
VOC image annotations are described in XML files
shipped with VOC dataset, with one XML file per each image.
This function reads relevant object detection data from given
file and saves it to Python data structures.
Args:
voc_annotation_xml (str): VOC annotation XML file path
Returns:
Python list of object detections metadata.
"""
tree = ET.parse(voc_annotiotion_xml)
size = tree.find('size')
objects = []
for obj in tree.findall('object'):
obj_struct = {}
obj_struct['image_width'] = size.find('width').text
obj_struct['image_height'] = size.find('height').text
obj_struct['name'] = obj.find('name').text
obj_struct['pose'] = obj.find('pose').text
obj_struct['truncated'] = int(obj.find('truncated').text)
obj_struct['difficult'] = int(obj.find('difficult').text)
bbox = obj.find('bndbox')
# Coordinates in VOC XMLs are in [1, 256] format, but we use [0, 255]
obj_struct['bbox'] = [int(bbox.find('xmin').text) - 1,
int(bbox.find('ymin').text) - 1,
int(bbox.find('xmax').text) - 1,
int(bbox.find('ymax').text) - 1]
objects.append(obj_struct)
return objects
def get_voc_results_file_template(cls, results_dir):
"""Fetches inference detection result file path for given class.
During TensorRT/Tensorflow inference, we save class detections into
separate files, for later mAP computation. This function fetches
paths of these files.
Args:
cls (str): VOC class label
results_dir (str): path of directory containing detection results
Returns:
str: Detection results path for given class.
"""
# VOCdevkit/VOC2007/results/det_test_aeroplane.txt
filename = 'det_test_{}.txt'.format(cls)
if not os.path.exists(results_dir):
os.makedirs(results_dir)
path = os.path.join(results_dir, filename)
return path
def do_python_eval(results_dir):
cachedir = PATHS.get_voc_annotation_cache_path()
aps = []
for i, cls in enumerate(voc_utils.VOC_CLASSES_LIST):
filename = get_voc_results_file_template(cls, results_dir)
rec, prec, ap = voc_eval(
filename,
PATHS.get_voc_image_set_path(),
cls, cachedir,
ovthresh=0.5)
aps += [ap]
print('AP for {} = {:.4f}'.format(cls, ap))
print('Mean AP = {:.4f}'.format(np.mean(aps)))
def voc_ap(rec, prec):
ap = 0.
for t in np.arange(0., 1.1, 0.1):
if np.sum(rec >= t) == 0:
p = 0
else:
p = np.max(prec[rec >= t])
ap = ap + p / 11.
return ap
def read_voc_annotations(annotations_dir, image_numbers):
if not os.path.isdir(annotations_dir):
os.makedirs(annotations_dir)
annotations_file = os.path.join(annotations_dir, 'annots.pkl')
if not os.path.isfile(annotations_file):
# If annotations were not present, compute them
detections = {}
for i, image_num in enumerate(image_numbers):
detections[image_num] = parse_voc_annotation_xml(
PATHS.get_voc_annotation_path().format(image_num))
if i % 100 == 0:
print('Reading annotation for {:d}/{:d}'.format(
i + 1, len(image_numbers)))
# Save
print('Saving cached annotations to {:s}'.format(annotations_file))
with open(annotations_file, 'wb') as f:
pickle.dump(detections, f)
else:
# If annotations were present, load them
with open(annotations_file, 'rb') as f:
detections = pickle.load(f)
return detections
def extract_class_detetions(voc_detections, classname, image_numbers):
class_detections = {}
for image_num in image_numbers:
R = [obj for obj in voc_detections[image_num] if obj['name'] == classname]
image_bboxes = [x['bbox'] for x in R]
# Transform VOC bboxes to make them describe pre-resized 300x300 images
for idx, bbox in enumerate(image_bboxes):
bbox = np.array(bbox).astype(np.float32)
width = float(R[0]['image_width'])
height = float(R[0]['image_height'])
bbox[0] *= (300.0 / width)
bbox[2] *= (300.0 / width)
bbox[1] *= (300.0 / height)
bbox[3] *= (300.0 / height)
image_bboxes[idx] = bbox
image_bboxes = np.array(image_bboxes)
difficult = np.array([x['difficult'] for x in R]).astype(np.bool)
det = [False] * len(R)
class_detections[image_num] = {
'bbox': image_bboxes,
'difficult': difficult,
'det': det
}
return class_detections
def voc_eval(detpath,
imagesetfile,
classname,
cachedir,
ovthresh=0.5):
with open(imagesetfile, 'r') as f:
lines = f.readlines()
image_numbers = [x.strip() for x in lines]
voc_detections = read_voc_annotations(cachedir, image_numbers)
class_detections = extract_class_detetions(voc_detections, classname,
image_numbers)
is_detection_difficult = np.concatenate(
[class_detections[image_num]['difficult'] for image_num in image_numbers]
)
not_difficult_count = sum(~is_detection_difficult)
# Read detections outputed by model
detfile = detpath.format(classname)
with open(detfile, 'r') as f:
lines = f.readlines()
if any(lines):
splitlines = [x.strip().split(' ') for x in lines]
image_ids = [x[0] for x in splitlines]
confidence = np.array([float(x[1]) for x in splitlines])
bboxes = np.array([[float(z) for z in x[2:]] for x in splitlines])
# sort by confidence
sorted_ind = np.argsort(-confidence)
sorted_scores = np.sort(-confidence)
bboxes = bboxes[sorted_ind, :]
image_ids = [image_ids[x] for x in sorted_ind]
# Go down dets and mark TPs and FPs
num_detections = len(image_ids)
tp = np.zeros(num_detections)
fp = np.zeros(num_detections)
for detection in range(num_detections):
R = class_detections[image_ids[detection]]
bbox = bboxes[detection, :].astype(float)
ovmax = -np.inf
bbox_gt = R['bbox'].astype(float)
if bbox_gt.size > 0:
# compute overlaps
# intersection
ixmin = np.maximum(bbox_gt[:, 0], bbox[0])
iymin = np.maximum(bbox_gt[:, 1], bbox[1])
ixmax = np.minimum(bbox_gt[:, 2], bbox[2])
iymax = np.minimum(bbox_gt[:, 3], bbox[3])
iw = np.maximum(ixmax - ixmin, 0.)
ih = np.maximum(iymax - iymin, 0.)
inters = iw * ih
uni = ((bbox[2] - bbox[0]) * (bbox[3] - bbox[1]) +
(bbox_gt[:, 2] - bbox_gt[:, 0]) *
(bbox_gt[:, 3] - bbox_gt[:, 1]) - inters)
overlaps = inters / uni
ovmax = np.max(overlaps)
jmax = np.argmax(overlaps)
if ovmax > ovthresh:
if not R['difficult'][jmax]:
if not R['det'][jmax]:
tp[detection] = 1.
R['det'][jmax] = 1
else:
fp[detection] = 1.
else:
fp[detection] = 1.
# Compute precision and recall
fp = np.cumsum(fp)
tp = np.cumsum(tp)
rec = tp / float(not_difficult_count)
# avoid divide by zero in case the first detection matches a difficult
# ground truth
prec = tp / np.maximum(tp + fp, np.finfo(np.float64).eps)
ap = voc_ap(rec, prec)
else:
rec = -1.
prec = -1.
ap = -1.
return rec, prec, ap