File size: 7,269 Bytes
6f6830f
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
# -*- coding: utf-8 -*-
# Copyright (c) Facebook, Inc. and its affiliates.

import contextlib
import io
import numpy as np
import unittest
from collections import defaultdict
import torch
import tqdm
from fvcore.common.benchmark import benchmark
from pycocotools.coco import COCO
from tabulate import tabulate
from torch.nn import functional as F

from detectron2.data import MetadataCatalog
from detectron2.layers.mask_ops import (
    pad_masks,
    paste_mask_in_image_old,
    paste_masks_in_image,
    scale_boxes,
)
from detectron2.structures import BitMasks, Boxes, BoxMode, PolygonMasks
from detectron2.structures.masks import polygons_to_bitmask
from detectron2.utils.file_io import PathManager
from detectron2.utils.testing import random_boxes


def iou_between_full_image_bit_masks(a, b):
    intersect = (a & b).sum()
    union = (a | b).sum()
    return intersect / union


def rasterize_polygons_with_grid_sample(full_image_bit_mask, box, mask_size, threshold=0.5):
    x0, y0, x1, y1 = box[0], box[1], box[2], box[3]

    img_h, img_w = full_image_bit_mask.shape

    mask_y = np.arange(0.0, mask_size) + 0.5  # mask y sample coords in [0.5, mask_size - 0.5]
    mask_x = np.arange(0.0, mask_size) + 0.5  # mask x sample coords in [0.5, mask_size - 0.5]
    mask_y = mask_y / mask_size * (y1 - y0) + y0
    mask_x = mask_x / mask_size * (x1 - x0) + x0

    mask_x = (mask_x - 0.5) / (img_w - 1) * 2 + -1
    mask_y = (mask_y - 0.5) / (img_h - 1) * 2 + -1
    gy, gx = torch.meshgrid(torch.from_numpy(mask_y), torch.from_numpy(mask_x))
    ind = torch.stack([gx, gy], dim=-1).to(dtype=torch.float32)

    full_image_bit_mask = torch.from_numpy(full_image_bit_mask)
    mask = F.grid_sample(
        full_image_bit_mask[None, None, :, :].to(dtype=torch.float32),
        ind[None, :, :, :],
        align_corners=True,
    )

    return mask[0, 0] >= threshold


class TestMaskCropPaste(unittest.TestCase):
    def setUp(self):
        json_file = MetadataCatalog.get("coco_2017_val_100").json_file
        if not PathManager.isfile(json_file):
            raise unittest.SkipTest("{} not found".format(json_file))
        with contextlib.redirect_stdout(io.StringIO()):
            json_file = PathManager.get_local_path(json_file)
            self.coco = COCO(json_file)

    def test_crop_paste_consistency(self):
        """
        rasterize_polygons_within_box (used in training)
        and
        paste_masks_in_image (used in inference)
        should be inverse operations to each other.

        This function runs several implementation of the above two operations and prints
        the reconstruction error.
        """

        anns = self.coco.loadAnns(self.coco.getAnnIds(iscrowd=False))  # avoid crowd annotations

        selected_anns = anns[:100]

        ious = []
        for ann in tqdm.tqdm(selected_anns):
            results = self.process_annotation(ann)
            ious.append([k[2] for k in results])

        ious = np.array(ious)
        mean_ious = ious.mean(axis=0)
        table = []
        res_dic = defaultdict(dict)
        for row, iou in zip(results, mean_ious):
            table.append((row[0], row[1], iou))
            res_dic[row[0]][row[1]] = iou
        print(tabulate(table, headers=["rasterize", "paste", "iou"], tablefmt="simple"))
        # assert that the reconstruction is good:
        self.assertTrue(res_dic["polygon"]["aligned"] > 0.94)
        self.assertTrue(res_dic["roialign"]["aligned"] > 0.95)

    def process_annotation(self, ann, mask_side_len=28):
        # Parse annotation data
        img_info = self.coco.loadImgs(ids=[ann["image_id"]])[0]
        height, width = img_info["height"], img_info["width"]
        gt_polygons = [np.array(p, dtype=np.float64) for p in ann["segmentation"]]
        gt_bbox = BoxMode.convert(ann["bbox"], BoxMode.XYWH_ABS, BoxMode.XYXY_ABS)
        gt_bit_mask = polygons_to_bitmask(gt_polygons, height, width)

        # Run rasterize ..
        torch_gt_bbox = torch.tensor(gt_bbox).to(dtype=torch.float32).reshape(-1, 4)
        box_bitmasks = {
            "polygon": PolygonMasks([gt_polygons]).crop_and_resize(torch_gt_bbox, mask_side_len)[0],
            "gridsample": rasterize_polygons_with_grid_sample(gt_bit_mask, gt_bbox, mask_side_len),
            "roialign": BitMasks(torch.from_numpy(gt_bit_mask[None, :, :])).crop_and_resize(
                torch_gt_bbox, mask_side_len
            )[0],
        }

        # Run paste ..
        results = defaultdict(dict)
        for k, box_bitmask in box_bitmasks.items():
            padded_bitmask, scale = pad_masks(box_bitmask[None, :, :], 1)
            scaled_boxes = scale_boxes(torch_gt_bbox, scale)

            r = results[k]
            r["old"] = paste_mask_in_image_old(
                padded_bitmask[0], scaled_boxes[0], height, width, threshold=0.5
            )
            r["aligned"] = paste_masks_in_image(
                box_bitmask[None, :, :], Boxes(torch_gt_bbox), (height, width)
            )[0]

        table = []
        for rasterize_method, r in results.items():
            for paste_method, mask in r.items():
                mask = np.asarray(mask)
                iou = iou_between_full_image_bit_masks(gt_bit_mask.astype("uint8"), mask)
                table.append((rasterize_method, paste_method, iou))
        return table

    def test_polygon_area(self):
        # Draw polygon boxes
        for d in [5.0, 10.0, 1000.0]:
            polygon = PolygonMasks([[[0, 0, 0, d, d, d, d, 0]]])
            area = polygon.area()[0]
            target = d ** 2
            self.assertEqual(area, target)

        # Draw polygon triangles
        for d in [5.0, 10.0, 1000.0]:
            polygon = PolygonMasks([[[0, 0, 0, d, d, d]]])
            area = polygon.area()[0]
            target = d ** 2 / 2
            self.assertEqual(area, target)

    def test_paste_mask_scriptable(self):
        scripted_f = torch.jit.script(paste_masks_in_image)
        N = 10
        masks = torch.rand(N, 28, 28)
        boxes = Boxes(random_boxes(N, 100)).tensor
        image_shape = (150, 150)

        out = paste_masks_in_image(masks, boxes, image_shape)
        scripted_out = scripted_f(masks, boxes, image_shape)
        self.assertTrue(torch.equal(out, scripted_out))


def benchmark_paste():
    S = 800
    H, W = image_shape = (S, S)
    N = 64
    torch.manual_seed(42)
    masks = torch.rand(N, 28, 28)

    center = torch.rand(N, 2) * 600 + 100
    wh = torch.clamp(torch.randn(N, 2) * 40 + 200, min=50)
    x0y0 = torch.clamp(center - wh * 0.5, min=0.0)
    x1y1 = torch.clamp(center + wh * 0.5, max=S)
    boxes = Boxes(torch.cat([x0y0, x1y1], axis=1))

    def func(device, n=3):
        m = masks.to(device=device)
        b = boxes.to(device=device)

        def bench():
            for _ in range(n):
                paste_masks_in_image(m, b, image_shape)
            if device.type == "cuda":
                torch.cuda.synchronize()

        return bench

    specs = [{"device": torch.device("cpu"), "n": 3}]
    if torch.cuda.is_available():
        specs.append({"device": torch.device("cuda"), "n": 3})

    benchmark(func, "paste_masks", specs, num_iters=10, warmup_iters=2)


if __name__ == "__main__":
    benchmark_paste()
    unittest.main()