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tinygrab/models/mask_rcnn.py

1274 lines
41 KiB
Python

import re
import math
import os
import numpy as np
from pathlib import Path
from tinygrad import nn
from tinygrad.tensor import Tensor
from tinygrad.helpers import dtypes
from extra.utils import get_child, download_file
from tinygrad.state import torch_load
from models.resnet import ResNet
from models.retinanet import nms as _box_nms
USE_NP_GATHER = os.getenv('FULL_TINYGRAD', '0') == '0'
def rint(tensor):
x = (tensor*2).cast(dtypes.int32).contiguous().cast(dtypes.float32)/2
return (x<0).where(x.floor(), x.ceil())
def nearest_interpolate(tensor, scale_factor):
bs, c, py, px = tensor.shape
return tensor.reshape(bs, c, py, 1, px, 1).expand(bs, c, py, scale_factor, px, scale_factor).reshape(bs, c, py * scale_factor, px * scale_factor)
def meshgrid(x, y):
grid_x = Tensor.cat(*[x[idx:idx+1].expand(y.shape).unsqueeze(0) for idx in range(x.shape[0])])
grid_y = Tensor.cat(*[y.unsqueeze(0)]*x.shape[0])
return grid_x.reshape(-1, 1), grid_y.reshape(-1, 1)
def topk(input_, k, dim=-1, largest=True, sorted=False):
k = min(k, input_.shape[dim]-1)
input_ = input_.numpy()
if largest: input_ *= -1
ind = np.argpartition(input_, k, axis=dim)
if largest: input_ *= -1
ind = np.take(ind, np.arange(k), axis=dim) # k non-sorted indices
input_ = np.take_along_axis(input_, ind, axis=dim) # k non-sorted values
if not sorted: return Tensor(input_), ind
if largest: input_ *= -1
ind_part = np.argsort(input_, axis=dim)
ind = np.take_along_axis(ind, ind_part, axis=dim)
if largest: input_ *= -1
val = np.take_along_axis(input_, ind_part, axis=dim)
return Tensor(val), ind
# This is very slow for large arrays, or indices
def _gather(array, indices):
indices = indices.float().to(array.device)
reshape_arg = [1]*array.ndim + [array.shape[-1]]
return Tensor.where(
indices.unsqueeze(indices.ndim).expand(*indices.shape, array.shape[-1]) == Tensor.arange(array.shape[-1]).reshape(*reshape_arg).expand(*indices.shape, array.shape[-1]),
array, 0,
).sum(indices.ndim)
# TODO: replace npgather with a faster gather using tinygrad only
# NOTE: this blocks the gradient
def npgather(array,indices):
if isinstance(array, Tensor): array = array.numpy()
if isinstance(indices, Tensor): indices = indices.numpy()
if isinstance(indices, list): indices = np.asarray(indices)
return Tensor(array[indices.astype(int)])
def get_strides(shape):
prod = [1]
for idx in range(len(shape)-1, -1, -1): prod.append(prod[-1] * shape[idx])
# something about ints is broken with gpu, cuda
return Tensor(prod[::-1][1:], dtype=dtypes.int32).unsqueeze(0).cpu()
# with keys as integer array for all axes
def tensor_getitem(tensor, *keys):
# something about ints is broken with gpu, cuda
flat_keys = Tensor.stack([key.expand((sum(keys)).shape).reshape(-1) for key in keys], dim=1).cpu().cast(dtypes.int32)
strides = get_strides(tensor.shape)
idxs = (flat_keys * strides).sum(1)
gatherer = npgather if USE_NP_GATHER else _gather
return gatherer(tensor.reshape(-1), idxs).reshape(sum(keys).shape)
# for gather with indicies only on axis=0
def tensor_gather(tensor, indices):
if not isinstance(indices, Tensor):
indices = Tensor(indices, requires_grad=False)
if len(tensor.shape) > 2:
rem_shape = list(tensor.shape)[1:]
tensor = tensor.reshape(tensor.shape[0], -1)
else:
rem_shape = None
if len(tensor.shape) > 1:
tensor = tensor.T
repeat_arg = [1]*(tensor.ndim-1) + [tensor.shape[-2]]
indices = indices.unsqueeze(indices.ndim).repeat(repeat_arg)
ret = _gather(tensor, indices)
if rem_shape:
ret = ret.reshape([indices.shape[0]] + rem_shape)
else:
ret = _gather(tensor, indices)
del indices
return ret
class LastLevelMaxPool:
def __call__(self, x): return [Tensor.max_pool2d(x, 1, 2)]
# transpose
FLIP_LEFT_RIGHT = 0
FLIP_TOP_BOTTOM = 1
def permute_and_flatten(layer:Tensor, N, A, C, H, W):
layer = layer.reshape(N, -1, C, H, W)
layer = layer.permute(0, 3, 4, 1, 2)
layer = layer.reshape(N, -1, C)
return layer
class BoxList:
def __init__(self, bbox, image_size, mode="xyxy"):
if not isinstance(bbox, Tensor):
bbox = Tensor(bbox)
if bbox.ndim != 2:
raise ValueError(
"bbox should have 2 dimensions, got {}".format(bbox.ndim)
)
if bbox.shape[-1] != 4:
raise ValueError(
"last dimenion of bbox should have a "
"size of 4, got {}".format(bbox.shape[-1])
)
if mode not in ("xyxy", "xywh"):
raise ValueError("mode should be 'xyxy' or 'xywh'")
self.bbox = bbox
self.size = image_size # (image_width, image_height)
self.mode = mode
self.extra_fields = {}
def __repr__(self):
s = self.__class__.__name__ + "("
s += "num_boxes={}, ".format(len(self))
s += "image_width={}, ".format(self.size[0])
s += "image_height={}, ".format(self.size[1])
s += "mode={})".format(self.mode)
return s
def area(self):
box = self.bbox
if self.mode == "xyxy":
TO_REMOVE = 1
area = (box[:, 2] - box[:, 0] + TO_REMOVE) * (box[:, 3] - box[:, 1] + TO_REMOVE)
elif self.mode == "xywh":
area = box[:, 2] * box[:, 3]
return area
def add_field(self, field, field_data):
self.extra_fields[field] = field_data
def get_field(self, field):
return self.extra_fields[field]
def has_field(self, field):
return field in self.extra_fields
def fields(self):
return list(self.extra_fields.keys())
def _copy_extra_fields(self, bbox):
for k, v in bbox.extra_fields.items():
self.extra_fields[k] = v
def convert(self, mode):
if mode == self.mode:
return self
xmin, ymin, xmax, ymax = self._split_into_xyxy()
if mode == "xyxy":
bbox = Tensor.cat(*(xmin, ymin, xmax, ymax), dim=-1)
bbox = BoxList(bbox, self.size, mode=mode)
else:
TO_REMOVE = 1
bbox = Tensor.cat(
*(xmin, ymin, xmax - xmin + TO_REMOVE, ymax - ymin + TO_REMOVE), dim=-1
)
bbox = BoxList(bbox, self.size, mode=mode)
bbox._copy_extra_fields(self)
return bbox
def _split_into_xyxy(self):
if self.mode == "xyxy":
xmin, ymin, xmax, ymax = self.bbox.chunk(4, dim=-1)
return xmin, ymin, xmax, ymax
if self.mode == "xywh":
TO_REMOVE = 1
xmin, ymin, w, h = self.bbox.chunk(4, dim=-1)
return (
xmin,
ymin,
xmin + (w - TO_REMOVE).clamp(min=0),
ymin + (h - TO_REMOVE).clamp(min=0),
)
def resize(self, size, *args, **kwargs):
ratios = tuple(float(s) / float(s_orig) for s, s_orig in zip(size, self.size))
if ratios[0] == ratios[1]:
ratio = ratios[0]
scaled_box = self.bbox * ratio
bbox = BoxList(scaled_box, size, mode=self.mode)
for k, v in self.extra_fields.items():
if not isinstance(v, Tensor):
v = v.resize(size, *args, **kwargs)
bbox.add_field(k, v)
return bbox
ratio_width, ratio_height = ratios
xmin, ymin, xmax, ymax = self._split_into_xyxy()
scaled_xmin = xmin * ratio_width
scaled_xmax = xmax * ratio_width
scaled_ymin = ymin * ratio_height
scaled_ymax = ymax * ratio_height
scaled_box = Tensor.cat(
*(scaled_xmin, scaled_ymin, scaled_xmax, scaled_ymax), dim=-1
)
bbox = BoxList(scaled_box, size, mode="xyxy")
for k, v in self.extra_fields.items():
if not isinstance(v, Tensor):
v = v.resize(size, *args, **kwargs)
bbox.add_field(k, v)
return bbox.convert(self.mode)
def transpose(self, method):
image_width, image_height = self.size
xmin, ymin, xmax, ymax = self._split_into_xyxy()
if method == FLIP_LEFT_RIGHT:
TO_REMOVE = 1
transposed_xmin = image_width - xmax - TO_REMOVE
transposed_xmax = image_width - xmin - TO_REMOVE
transposed_ymin = ymin
transposed_ymax = ymax
elif method == FLIP_TOP_BOTTOM:
transposed_xmin = xmin
transposed_xmax = xmax
transposed_ymin = image_height - ymax
transposed_ymax = image_height - ymin
transposed_boxes = Tensor.cat(
*(transposed_xmin, transposed_ymin, transposed_xmax, transposed_ymax), dim=-1
)
bbox = BoxList(transposed_boxes, self.size, mode="xyxy")
for k, v in self.extra_fields.items():
if not isinstance(v, Tensor):
v = v.transpose(method)
bbox.add_field(k, v)
return bbox.convert(self.mode)
def clip_to_image(self, remove_empty=True):
TO_REMOVE = 1
bb1 = self.bbox.clip(min_=0, max_=self.size[0] - TO_REMOVE)[:, 0]
bb2 = self.bbox.clip(min_=0, max_=self.size[1] - TO_REMOVE)[:, 1]
bb3 = self.bbox.clip(min_=0, max_=self.size[0] - TO_REMOVE)[:, 2]
bb4 = self.bbox.clip(min_=0, max_=self.size[1] - TO_REMOVE)[:, 3]
self.bbox = Tensor.stack((bb1, bb2, bb3, bb4), dim=1)
if remove_empty:
box = self.bbox
keep = (box[:, 3] > box[:, 1]) & (box[:, 2] > box[:, 0])
return self[keep]
return self
def __getitem__(self, item):
if isinstance(item, list):
if len(item) == 0:
return []
if sum(item) == len(item) and isinstance(item[0], bool):
return self
bbox = BoxList(tensor_gather(self.bbox, item), self.size, self.mode)
for k, v in self.extra_fields.items():
bbox.add_field(k, tensor_gather(v, item))
return bbox
def __len__(self):
return self.bbox.shape[0]
def cat_boxlist(bboxes):
size = bboxes[0].size
mode = bboxes[0].mode
fields = set(bboxes[0].fields())
cat_box_list = [bbox.bbox for bbox in bboxes if bbox.bbox.shape[0] > 0]
if len(cat_box_list) > 0:
cat_boxes = BoxList(Tensor.cat(*cat_box_list, dim=0), size, mode)
else:
cat_boxes = BoxList(bboxes[0].bbox, size, mode)
for field in fields:
cat_field_list = [bbox.get_field(field) for bbox in bboxes if bbox.get_field(field).shape[0] > 0]
if len(cat_box_list) > 0:
data = Tensor.cat(*cat_field_list, dim=0)
else:
data = bboxes[0].get_field(field)
cat_boxes.add_field(field, data)
return cat_boxes
class FPN:
def __init__(self, in_channels_list, out_channels):
self.inner_blocks, self.layer_blocks = [], []
for in_channels in in_channels_list:
self.inner_blocks.append(nn.Conv2d(in_channels, out_channels, kernel_size=1))
self.layer_blocks.append(nn.Conv2d(out_channels, out_channels, kernel_size=3, padding=1))
self.top_block = LastLevelMaxPool()
def __call__(self, x: Tensor):
last_inner = self.inner_blocks[-1](x[-1])
results = []
results.append(self.layer_blocks[-1](last_inner))
for feature, inner_block, layer_block in zip(
x[:-1][::-1], self.inner_blocks[:-1][::-1], self.layer_blocks[:-1][::-1]
):
if not inner_block:
continue
inner_top_down = nearest_interpolate(last_inner, scale_factor=2)
inner_lateral = inner_block(feature)
last_inner = inner_lateral + inner_top_down
layer_result = layer_block(last_inner)
results.insert(0, layer_result)
last_results = self.top_block(results[-1])
results.extend(last_results)
return tuple(results)
class ResNetFPN:
def __init__(self, resnet, out_channels=256):
self.out_channels = out_channels
self.body = resnet
in_channels_stage2 = 256
in_channels_list = [
in_channels_stage2,
in_channels_stage2 * 2,
in_channels_stage2 * 4,
in_channels_stage2 * 8,
]
self.fpn = FPN(in_channels_list, out_channels)
def __call__(self, x):
x = self.body(x)
return self.fpn(x)
class AnchorGenerator:
def __init__(
self,
sizes=(32, 64, 128, 256, 512),
aspect_ratios=(0.5, 1.0, 2.0),
anchor_strides=(4, 8, 16, 32, 64),
straddle_thresh=0,
):
if len(anchor_strides) == 1:
anchor_stride = anchor_strides[0]
cell_anchors = [
generate_anchors(anchor_stride, sizes, aspect_ratios)
]
else:
if len(anchor_strides) != len(sizes):
raise RuntimeError("FPN should have #anchor_strides == #sizes")
cell_anchors = [
generate_anchors(
anchor_stride,
size if isinstance(size, (tuple, list)) else (size,),
aspect_ratios
)
for anchor_stride, size in zip(anchor_strides, sizes)
]
self.strides = anchor_strides
self.cell_anchors = cell_anchors
self.straddle_thresh = straddle_thresh
def num_anchors_per_location(self):
return [cell_anchors.shape[0] for cell_anchors in self.cell_anchors]
def grid_anchors(self, grid_sizes):
anchors = []
for size, stride, base_anchors in zip(
grid_sizes, self.strides, self.cell_anchors
):
grid_height, grid_width = size
device = base_anchors.device
shifts_x = Tensor.arange(
start=0, stop=grid_width * stride, step=stride, dtype=dtypes.float32, device=device
)
shifts_y = Tensor.arange(
start=0, stop=grid_height * stride, step=stride, dtype=dtypes.float32, device=device
)
shift_y, shift_x = meshgrid(shifts_y, shifts_x)
shift_x = shift_x.reshape(-1)
shift_y = shift_y.reshape(-1)
shifts = Tensor.stack((shift_x, shift_y, shift_x, shift_y), dim=1)
anchors.append(
(shifts.reshape(-1, 1, 4) + base_anchors.reshape(1, -1, 4)).reshape(-1, 4)
)
return anchors
def add_visibility_to(self, boxlist):
image_width, image_height = boxlist.size
anchors = boxlist.bbox
if self.straddle_thresh >= 0:
inds_inside = (
(anchors[:, 0] >= -self.straddle_thresh)
* (anchors[:, 1] >= -self.straddle_thresh)
* (anchors[:, 2] < image_width + self.straddle_thresh)
* (anchors[:, 3] < image_height + self.straddle_thresh)
)
else:
device = anchors.device
inds_inside = Tensor.ones(anchors.shape[0], dtype=dtypes.uint8, device=device)
boxlist.add_field("visibility", inds_inside)
def __call__(self, image_list, feature_maps):
grid_sizes = [feature_map.shape[-2:] for feature_map in feature_maps]
anchors_over_all_feature_maps = self.grid_anchors(grid_sizes)
anchors = []
for (image_height, image_width) in image_list.image_sizes:
anchors_in_image = []
for anchors_per_feature_map in anchors_over_all_feature_maps:
boxlist = BoxList(
anchors_per_feature_map, (image_width, image_height), mode="xyxy"
)
self.add_visibility_to(boxlist)
anchors_in_image.append(boxlist)
anchors.append(anchors_in_image)
return anchors
def generate_anchors(
stride=16, sizes=(32, 64, 128, 256, 512), aspect_ratios=(0.5, 1, 2)
):
return _generate_anchors(stride, Tensor(list(sizes)) / stride, Tensor(list(aspect_ratios)))
def _generate_anchors(base_size, scales, aspect_ratios):
anchor = Tensor([1, 1, base_size, base_size]) - 1
anchors = _ratio_enum(anchor, aspect_ratios)
anchors = Tensor.cat(
*[_scale_enum(anchors[i, :], scales).reshape(-1, 4) for i in range(anchors.shape[0])]
)
return anchors
def _whctrs(anchor):
w = anchor[2] - anchor[0] + 1
h = anchor[3] - anchor[1] + 1
x_ctr = anchor[0] + 0.5 * (w - 1)
y_ctr = anchor[1] + 0.5 * (h - 1)
return w, h, x_ctr, y_ctr
def _mkanchors(ws, hs, x_ctr, y_ctr):
ws = ws[:, None]
hs = hs[:, None]
anchors = Tensor.cat(*(
x_ctr - 0.5 * (ws - 1),
y_ctr - 0.5 * (hs - 1),
x_ctr + 0.5 * (ws - 1),
y_ctr + 0.5 * (hs - 1),
), dim=1)
return anchors
def _ratio_enum(anchor, ratios):
w, h, x_ctr, y_ctr = _whctrs(anchor)
size = w * h
size_ratios = size / ratios
ws = rint(Tensor.sqrt(size_ratios))
hs = rint(ws * ratios)
anchors = _mkanchors(ws, hs, x_ctr, y_ctr)
return anchors
def _scale_enum(anchor, scales):
w, h, x_ctr, y_ctr = _whctrs(anchor)
ws = w * scales
hs = h * scales
anchors = _mkanchors(ws, hs, x_ctr, y_ctr)
return anchors
class RPNHead:
def __init__(self, in_channels, num_anchors):
self.conv = nn.Conv2d(in_channels, 256, kernel_size=3, padding=1)
self.cls_logits = nn.Conv2d(256, num_anchors, kernel_size=1)
self.bbox_pred = nn.Conv2d(256, num_anchors * 4, kernel_size=1)
def __call__(self, x):
logits = []
bbox_reg = []
for feature in x:
t = Tensor.relu(self.conv(feature))
logits.append(self.cls_logits(t))
bbox_reg.append(self.bbox_pred(t))
return logits, bbox_reg
class BoxCoder(object):
def __init__(self, weights, bbox_xform_clip=math.log(1000. / 16)):
self.weights = weights
self.bbox_xform_clip = bbox_xform_clip
def encode(self, reference_boxes, proposals):
TO_REMOVE = 1 # TODO remove
ex_widths = proposals[:, 2] - proposals[:, 0] + TO_REMOVE
ex_heights = proposals[:, 3] - proposals[:, 1] + TO_REMOVE
ex_ctr_x = proposals[:, 0] + 0.5 * ex_widths
ex_ctr_y = proposals[:, 1] + 0.5 * ex_heights
gt_widths = reference_boxes[:, 2] - reference_boxes[:, 0] + TO_REMOVE
gt_heights = reference_boxes[:, 3] - reference_boxes[:, 1] + TO_REMOVE
gt_ctr_x = reference_boxes[:, 0] + 0.5 * gt_widths
gt_ctr_y = reference_boxes[:, 1] + 0.5 * gt_heights
wx, wy, ww, wh = self.weights
targets_dx = wx * (gt_ctr_x - ex_ctr_x) / ex_widths
targets_dy = wy * (gt_ctr_y - ex_ctr_y) / ex_heights
targets_dw = ww * Tensor.log(gt_widths / ex_widths)
targets_dh = wh * Tensor.log(gt_heights / ex_heights)
targets = Tensor.stack((targets_dx, targets_dy, targets_dw, targets_dh), dim=1)
return targets
def decode(self, rel_codes, boxes):
boxes = boxes.cast(rel_codes.dtype)
rel_codes = rel_codes
TO_REMOVE = 1 # TODO remove
widths = boxes[:, 2] - boxes[:, 0] + TO_REMOVE
heights = boxes[:, 3] - boxes[:, 1] + TO_REMOVE
ctr_x = boxes[:, 0] + 0.5 * widths
ctr_y = boxes[:, 1] + 0.5 * heights
wx, wy, ww, wh = self.weights
dx = rel_codes[:, 0::4] / wx
dy = rel_codes[:, 1::4] / wy
dw = rel_codes[:, 2::4] / ww
dh = rel_codes[:, 3::4] / wh
# Prevent sending too large values into Tensor.exp()
dw = dw.clip(min_=dw.min(), max_=self.bbox_xform_clip)
dh = dh.clip(min_=dh.min(), max_=self.bbox_xform_clip)
pred_ctr_x = dx * widths[:, None] + ctr_x[:, None]
pred_ctr_y = dy * heights[:, None] + ctr_y[:, None]
pred_w = dw.exp() * widths[:, None]
pred_h = dh.exp() * heights[:, None]
x = pred_ctr_x - 0.5 * pred_w
y = pred_ctr_y - 0.5 * pred_h
w = pred_ctr_x + 0.5 * pred_w - 1
h = pred_ctr_y + 0.5 * pred_h - 1
pred_boxes = Tensor.stack([x, y, w, h]).permute(1,2,0).reshape(rel_codes.shape[0], rel_codes.shape[1])
return pred_boxes
def boxlist_nms(boxlist, nms_thresh, max_proposals=-1, score_field="scores"):
if nms_thresh <= 0:
return boxlist
mode = boxlist.mode
boxlist = boxlist.convert("xyxy")
boxes = boxlist.bbox
score = boxlist.get_field(score_field)
keep = _box_nms(boxes.numpy(), score.numpy(), nms_thresh)
if max_proposals > 0:
keep = keep[:max_proposals]
boxlist = boxlist[keep]
return boxlist.convert(mode)
def remove_small_boxes(boxlist, min_size):
xywh_boxes = boxlist.convert("xywh").bbox
_, _, ws, hs = xywh_boxes.chunk(4, dim=1)
keep = ((
(ws >= min_size) * (hs >= min_size)
) > 0).reshape(-1)
if keep.sum().numpy() == len(boxlist):
return boxlist
else:
keep = keep.numpy().nonzero()[0]
return boxlist[keep]
class RPNPostProcessor:
# Not used in Loss calculation
def __init__(
self,
pre_nms_top_n,
post_nms_top_n,
nms_thresh,
min_size,
box_coder=None,
fpn_post_nms_top_n=None,
):
self.pre_nms_top_n = pre_nms_top_n
self.post_nms_top_n = post_nms_top_n
self.nms_thresh = nms_thresh
self.min_size = min_size
if box_coder is None:
box_coder = BoxCoder(weights=(1.0, 1.0, 1.0, 1.0))
self.box_coder = box_coder
if fpn_post_nms_top_n is None:
fpn_post_nms_top_n = post_nms_top_n
self.fpn_post_nms_top_n = fpn_post_nms_top_n
def forward_for_single_feature_map(self, anchors, objectness, box_regression):
device = objectness.device
N, A, H, W = objectness.shape
objectness = permute_and_flatten(objectness, N, A, 1, H, W).reshape(N, -1)
objectness = objectness.sigmoid()
box_regression = permute_and_flatten(box_regression, N, A, 4, H, W)
num_anchors = A * H * W
pre_nms_top_n = min(self.pre_nms_top_n, num_anchors)
objectness, topk_idx = topk(objectness, pre_nms_top_n, dim=1, sorted=False)
concat_anchors = Tensor.cat(*[a.bbox for a in anchors], dim=0).reshape(N, -1, 4)
image_shapes = [box.size for box in anchors]
box_regression_list = []
concat_anchors_list = []
for batch_idx in range(N):
box_regression_list.append(tensor_gather(box_regression[batch_idx], topk_idx[batch_idx]))
concat_anchors_list.append(tensor_gather(concat_anchors[batch_idx], topk_idx[batch_idx]))
box_regression = Tensor.stack(box_regression_list)
concat_anchors = Tensor.stack(concat_anchors_list)
proposals = self.box_coder.decode(
box_regression.reshape(-1, 4), concat_anchors.reshape(-1, 4)
)
proposals = proposals.reshape(N, -1, 4)
result = []
for proposal, score, im_shape in zip(proposals, objectness, image_shapes):
boxlist = BoxList(proposal, im_shape, mode="xyxy")
boxlist.add_field("objectness", score)
boxlist = boxlist.clip_to_image(remove_empty=False)
boxlist = remove_small_boxes(boxlist, self.min_size)
boxlist = boxlist_nms(
boxlist,
self.nms_thresh,
max_proposals=self.post_nms_top_n,
score_field="objectness",
)
result.append(boxlist)
return result
def __call__(self, anchors, objectness, box_regression):
sampled_boxes = []
num_levels = len(objectness)
anchors = list(zip(*anchors))
for a, o, b in zip(anchors, objectness, box_regression):
sampled_boxes.append(self.forward_for_single_feature_map(a, o, b))
boxlists = list(zip(*sampled_boxes))
boxlists = [cat_boxlist(boxlist) for boxlist in boxlists]
if num_levels > 1:
boxlists = self.select_over_all_levels(boxlists)
return boxlists
def select_over_all_levels(self, boxlists):
num_images = len(boxlists)
for i in range(num_images):
objectness = boxlists[i].get_field("objectness")
post_nms_top_n = min(self.fpn_post_nms_top_n, objectness.shape[0])
_, inds_sorted = topk(objectness,
post_nms_top_n, dim=0, sorted=False
)
boxlists[i] = boxlists[i][inds_sorted]
return boxlists
class RPN:
def __init__(self, in_channels):
self.anchor_generator = AnchorGenerator()
in_channels = 256
head = RPNHead(
in_channels, self.anchor_generator.num_anchors_per_location()[0]
)
rpn_box_coder = BoxCoder(weights=(1.0, 1.0, 1.0, 1.0))
box_selector_test = RPNPostProcessor(
pre_nms_top_n=1000,
post_nms_top_n=1000,
nms_thresh=0.7,
min_size=0,
box_coder=rpn_box_coder,
fpn_post_nms_top_n=1000
)
self.head = head
self.box_selector_test = box_selector_test
def __call__(self, images, features, targets=None):
objectness, rpn_box_regression = self.head(features)
anchors = self.anchor_generator(images, features)
boxes = self.box_selector_test(anchors, objectness, rpn_box_regression)
return boxes, {}
def make_conv3x3(
in_channels,
out_channels,
dilation=1,
stride=1,
use_gn=False,
):
conv = nn.Conv2d(
in_channels,
out_channels,
kernel_size=3,
stride=stride,
padding=dilation,
dilation=dilation,
bias=False if use_gn else True
)
return conv
class MaskRCNNFPNFeatureExtractor:
def __init__(self):
resolution = 14
scales = (0.25, 0.125, 0.0625, 0.03125)
sampling_ratio = 2
pooler = Pooler(
output_size=(resolution, resolution),
scales=scales,
sampling_ratio=sampling_ratio,
)
input_size = 256
self.pooler = pooler
use_gn = False
layers = (256, 256, 256, 256)
dilation = 1
self.mask_fcn1 = make_conv3x3(input_size, layers[0], dilation=dilation, stride=1, use_gn=use_gn)
self.mask_fcn2 = make_conv3x3(layers[0], layers[1], dilation=dilation, stride=1, use_gn=use_gn)
self.mask_fcn3 = make_conv3x3(layers[1], layers[2], dilation=dilation, stride=1, use_gn=use_gn)
self.mask_fcn4 = make_conv3x3(layers[2], layers[3], dilation=dilation, stride=1, use_gn=use_gn)
self.blocks = [self.mask_fcn1, self.mask_fcn2, self.mask_fcn3, self.mask_fcn4]
def __call__(self, x, proposals):
x = self.pooler(x, proposals)
for layer in self.blocks:
if x is not None:
x = Tensor.relu(layer(x))
return x
class MaskRCNNC4Predictor:
def __init__(self):
num_classes = 81
dim_reduced = 256
num_inputs = dim_reduced
self.conv5_mask = nn.ConvTranspose2d(num_inputs, dim_reduced, 2, 2, 0)
self.mask_fcn_logits = nn.Conv2d(dim_reduced, num_classes, 1, 1, 0)
def __call__(self, x):
x = Tensor.relu(self.conv5_mask(x))
return self.mask_fcn_logits(x)
class FPN2MLPFeatureExtractor:
def __init__(self, cfg):
resolution = 7
scales = (0.25, 0.125, 0.0625, 0.03125)
sampling_ratio = 2
pooler = Pooler(
output_size=(resolution, resolution),
scales=scales,
sampling_ratio=sampling_ratio,
)
input_size = 256 * resolution ** 2
representation_size = 1024
self.pooler = pooler
self.fc6 = nn.Linear(input_size, representation_size)
self.fc7 = nn.Linear(representation_size, representation_size)
def __call__(self, x, proposals):
x = self.pooler(x, proposals)
x = x.reshape(x.shape[0], -1)
x = Tensor.relu(self.fc6(x))
x = Tensor.relu(self.fc7(x))
return x
def _bilinear_interpolate(
input, # [N, C, H, W]
roi_batch_ind, # [K]
y, # [K, PH, IY]
x, # [K, PW, IX]
ymask, # [K, IY]
xmask, # [K, IX]
):
_, channels, height, width = input.shape
y = y.clip(min_=0.0, max_=float(height-1))
x = x.clip(min_=0.0, max_=float(width-1))
# Tensor.where doesnt work well with int32 data so cast to float32
y_low = y.cast(dtypes.int32).contiguous().float().contiguous()
x_low = x.cast(dtypes.int32).contiguous().float().contiguous()
y_high = Tensor.where(y_low >= height - 1, float(height - 1), y_low + 1)
y_low = Tensor.where(y_low >= height - 1, float(height - 1), y_low)
x_high = Tensor.where(x_low >= width - 1, float(width - 1), x_low + 1)
x_low = Tensor.where(x_low >= width - 1, float(width - 1), x_low)
ly = y - y_low
lx = x - x_low
hy = 1.0 - ly
hx = 1.0 - lx
def masked_index(
y, # [K, PH, IY]
x, # [K, PW, IX]
):
if ymask is not None:
assert xmask is not None
y = Tensor.where(ymask[:, None, :], y, 0)
x = Tensor.where(xmask[:, None, :], x, 0)
key1 = roi_batch_ind[:, None, None, None, None, None]
key2 = Tensor.arange(channels, device=input.device)[None, :, None, None, None, None]
key3 = y[:, None, :, None, :, None]
key4 = x[:, None, None, :, None, :]
return tensor_getitem(input,key1,key2,key3,key4) # [K, C, PH, PW, IY, IX]
v1 = masked_index(y_low, x_low)
v2 = masked_index(y_low, x_high)
v3 = masked_index(y_high, x_low)
v4 = masked_index(y_high, x_high)
# all ws preemptively [K, C, PH, PW, IY, IX]
def outer_prod(y, x):
return y[:, None, :, None, :, None] * x[:, None, None, :, None, :]
w1 = outer_prod(hy, hx)
w2 = outer_prod(hy, lx)
w3 = outer_prod(ly, hx)
w4 = outer_prod(ly, lx)
val = w1*v1 + w2*v2 + w3*v3 + w4*v4
return val
#https://pytorch.org/vision/main/_modules/torchvision/ops/roi_align.html#roi_align
def _roi_align(input, rois, spatial_scale, pooled_height, pooled_width, sampling_ratio, aligned):
orig_dtype = input.dtype
_, _, height, width = input.shape
ph = Tensor.arange(pooled_height, device=input.device)
pw = Tensor.arange(pooled_width, device=input.device)
roi_batch_ind = rois[:, 0].cast(dtypes.int32).contiguous()
offset = 0.5 if aligned else 0.0
roi_start_w = rois[:, 1] * spatial_scale - offset
roi_start_h = rois[:, 2] * spatial_scale - offset
roi_end_w = rois[:, 3] * spatial_scale - offset
roi_end_h = rois[:, 4] * spatial_scale - offset
roi_width = roi_end_w - roi_start_w
roi_height = roi_end_h - roi_start_h
if not aligned:
roi_width = roi_width.maximum(1.0)
roi_height = roi_height.maximum(1.0)
bin_size_h = roi_height / pooled_height
bin_size_w = roi_width / pooled_width
exact_sampling = sampling_ratio > 0
roi_bin_grid_h = sampling_ratio if exact_sampling else (roi_height / pooled_height).ceil()
roi_bin_grid_w = sampling_ratio if exact_sampling else (roi_width / pooled_width).ceil()
if exact_sampling:
count = max(roi_bin_grid_h * roi_bin_grid_w, 1)
iy = Tensor.arange(roi_bin_grid_h, device=input.device)
ix = Tensor.arange(roi_bin_grid_w, device=input.device)
ymask = None
xmask = None
else:
count = (roi_bin_grid_h * roi_bin_grid_w).maximum(1)
iy = Tensor.arange(height, device=input.device)
ix = Tensor.arange(width, device=input.device)
ymask = iy[None, :] < roi_bin_grid_h[:, None]
xmask = ix[None, :] < roi_bin_grid_w[:, None]
def from_K(t):
return t[:, None, None]
y = (
from_K(roi_start_h)
+ ph[None, :, None] * from_K(bin_size_h)
+ (iy[None, None, :] + 0.5) * from_K(bin_size_h / roi_bin_grid_h)
)
x = (
from_K(roi_start_w)
+ pw[None, :, None] * from_K(bin_size_w)
+ (ix[None, None, :] + 0.5) * from_K(bin_size_w / roi_bin_grid_w)
)
val = _bilinear_interpolate(input, roi_batch_ind, y, x, ymask, xmask)
if not exact_sampling:
val = ymask[:, None, None, None, :, None].where(val, 0)
val = xmask[:, None, None, None, None, :].where(val, 0)
output = val.sum((-1, -2))
if isinstance(count, Tensor):
output /= count[:, None, None, None]
else:
output /= count
output = output.cast(orig_dtype)
return output
class ROIAlign:
def __init__(self, output_size, spatial_scale, sampling_ratio):
self.output_size = output_size
self.spatial_scale = spatial_scale
self.sampling_ratio = sampling_ratio
def __call__(self, input, rois):
output = _roi_align(
input, rois, self.spatial_scale, self.output_size[0], self.output_size[1], self.sampling_ratio, aligned=False
)
return output
class LevelMapper:
def __init__(self, k_min, k_max, canonical_scale=224, canonical_level=4, eps=1e-6):
self.k_min = k_min
self.k_max = k_max
self.s0 = canonical_scale
self.lvl0 = canonical_level
self.eps = eps
def __call__(self, boxlists):
s = Tensor.sqrt(Tensor.cat(*[boxlist.area() for boxlist in boxlists]))
target_lvls = (self.lvl0 + Tensor.log2(s / self.s0 + self.eps)).floor()
target_lvls = target_lvls.clip(min_=self.k_min, max_=self.k_max)
return target_lvls - self.k_min
class Pooler:
def __init__(self, output_size, scales, sampling_ratio):
self.output_size = output_size
self.scales = scales
self.sampling_ratio = sampling_ratio
poolers = []
for scale in scales:
poolers.append(
ROIAlign(
output_size, spatial_scale=scale, sampling_ratio=sampling_ratio
)
)
self.poolers = poolers
self.output_size = output_size
lvl_min = -math.log2(scales[0])
lvl_max = -math.log2(scales[-1])
self.map_levels = LevelMapper(lvl_min, lvl_max)
def convert_to_roi_format(self, boxes):
concat_boxes = Tensor.cat(*[b.bbox for b in boxes], dim=0)
device, dtype = concat_boxes.device, concat_boxes.dtype
ids = Tensor.cat(
*[
Tensor.full((len(b), 1), i, dtype=dtype, device=device)
for i, b in enumerate(boxes)
],
dim=0,
)
if concat_boxes.shape[0] != 0:
rois = Tensor.cat(*[ids, concat_boxes], dim=1)
return rois
def __call__(self, x, boxes):
num_levels = len(self.poolers)
rois = self.convert_to_roi_format(boxes)
if rois:
if num_levels == 1:
return self.poolers[0](x[0], rois)
levels = self.map_levels(boxes)
results = []
all_idxs = []
for level, (per_level_feature, pooler) in enumerate(zip(x, self.poolers)):
# this is fine because no grad will flow through index
idx_in_level = (levels.numpy() == level).nonzero()[0]
if len(idx_in_level) > 0:
rois_per_level = tensor_gather(rois, idx_in_level)
pooler_output = pooler(per_level_feature, rois_per_level)
all_idxs.extend(idx_in_level)
results.append(pooler_output)
return tensor_gather(Tensor.cat(*results), [x[0] for x in sorted({i:idx for i, idx in enumerate(all_idxs)}.items(), key=lambda x: x[1])])
class FPNPredictor:
def __init__(self):
num_classes = 81
representation_size = 1024
self.cls_score = nn.Linear(representation_size, num_classes)
num_bbox_reg_classes = num_classes
self.bbox_pred = nn.Linear(representation_size, num_bbox_reg_classes * 4)
def __call__(self, x):
scores = self.cls_score(x)
bbox_deltas = self.bbox_pred(x)
return scores, bbox_deltas
class PostProcessor:
# Not used in training
def __init__(
self,
score_thresh=0.05,
nms=0.5,
detections_per_img=100,
box_coder=None,
cls_agnostic_bbox_reg=False
):
self.score_thresh = score_thresh
self.nms = nms
self.detections_per_img = detections_per_img
if box_coder is None:
box_coder = BoxCoder(weights=(10., 10., 5., 5.))
self.box_coder = box_coder
self.cls_agnostic_bbox_reg = cls_agnostic_bbox_reg
def __call__(self, x, boxes):
class_logits, box_regression = x
class_prob = Tensor.softmax(class_logits, -1)
image_shapes = [box.size for box in boxes]
boxes_per_image = [len(box) for box in boxes]
concat_boxes = Tensor.cat(*[a.bbox for a in boxes], dim=0)
if self.cls_agnostic_bbox_reg:
box_regression = box_regression[:, -4:]
proposals = self.box_coder.decode(
box_regression.reshape(sum(boxes_per_image), -1), concat_boxes
)
if self.cls_agnostic_bbox_reg:
proposals = proposals.repeat([1, class_prob.shape[1]])
num_classes = class_prob.shape[1]
proposals = proposals.unsqueeze(0)
class_prob = class_prob.unsqueeze(0)
results = []
for prob, boxes_per_img, image_shape in zip(
class_prob, proposals, image_shapes
):
boxlist = self.prepare_boxlist(boxes_per_img, prob, image_shape)
boxlist = boxlist.clip_to_image(remove_empty=False)
boxlist = self.filter_results(boxlist, num_classes)
results.append(boxlist)
return results
def prepare_boxlist(self, boxes, scores, image_shape):
boxes = boxes.reshape(-1, 4)
scores = scores.reshape(-1)
boxlist = BoxList(boxes, image_shape, mode="xyxy")
boxlist.add_field("scores", scores)
return boxlist
def filter_results(self, boxlist, num_classes):
boxes = boxlist.bbox.reshape(-1, num_classes * 4)
scores = boxlist.get_field("scores").reshape(-1, num_classes)
device = scores.device
result = []
scores = scores.numpy()
boxes = boxes.numpy()
inds_all = scores > self.score_thresh
for j in range(1, num_classes):
inds = inds_all[:, j].nonzero()[0]
# This needs to be done in numpy because it can create empty arrays
scores_j = scores[inds, j]
boxes_j = boxes[inds, j * 4: (j + 1) * 4]
boxes_j = Tensor(boxes_j)
scores_j = Tensor(scores_j)
boxlist_for_class = BoxList(boxes_j, boxlist.size, mode="xyxy")
boxlist_for_class.add_field("scores", scores_j)
if len(boxlist_for_class):
boxlist_for_class = boxlist_nms(
boxlist_for_class, self.nms
)
num_labels = len(boxlist_for_class)
boxlist_for_class.add_field(
"labels", Tensor.full((num_labels,), j, device=device)
)
result.append(boxlist_for_class)
result = cat_boxlist(result)
number_of_detections = len(result)
if number_of_detections > self.detections_per_img > 0:
cls_scores = result.get_field("scores")
image_thresh, _ = topk(cls_scores, k=self.detections_per_img)
image_thresh = image_thresh.numpy()[-1]
keep = (cls_scores.numpy() >= image_thresh).nonzero()[0]
result = result[keep]
return result
class RoIBoxHead:
def __init__(self, in_channels):
self.feature_extractor = FPN2MLPFeatureExtractor(in_channels)
self.predictor = FPNPredictor()
self.post_processor = PostProcessor(
score_thresh=0.05,
nms=0.5,
detections_per_img=100,
box_coder=BoxCoder(weights=(10., 10., 5., 5.)),
cls_agnostic_bbox_reg=False
)
def __call__(self, features, proposals, targets=None):
x = self.feature_extractor(features, proposals)
class_logits, box_regression = self.predictor(x)
if not Tensor.training:
result = self.post_processor((class_logits, box_regression), proposals)
return x, result, {}
class MaskPostProcessor:
# Not used in loss calculation
def __call__(self, x, boxes):
mask_prob = x.sigmoid().numpy()
num_masks = x.shape[0]
labels = [bbox.get_field("labels") for bbox in boxes]
labels = Tensor.cat(*labels).numpy().astype(np.int32)
index = np.arange(num_masks)
mask_prob = mask_prob[index, labels][:, None]
boxes_per_image, cumsum = [], 0
for box in boxes:
cumsum += len(box)
boxes_per_image.append(cumsum)
# using numpy here as Tensor.chunk doesnt have custom chunk sizes
mask_prob = np.split(mask_prob, boxes_per_image, axis=0)
results = []
for prob, box in zip(mask_prob, boxes):
bbox = BoxList(box.bbox, box.size, mode="xyxy")
for field in box.fields():
bbox.add_field(field, box.get_field(field))
prob = Tensor(prob)
bbox.add_field("mask", prob)
results.append(bbox)
return results
class Mask:
def __init__(self):
self.feature_extractor = MaskRCNNFPNFeatureExtractor()
self.predictor = MaskRCNNC4Predictor()
self.post_processor = MaskPostProcessor()
def __call__(self, features, proposals, targets=None):
x = self.feature_extractor(features, proposals)
if x:
mask_logits = self.predictor(x)
if not Tensor.training:
result = self.post_processor(mask_logits, proposals)
return x, result, {}
return x, [], {}
class RoIHeads:
def __init__(self, in_channels):
self.box = RoIBoxHead(in_channels)
self.mask = Mask()
def __call__(self, features, proposals, targets=None):
x, detections, _ = self.box(features, proposals, targets)
x, detections, _ = self.mask(features, detections, targets)
return x, detections, {}
class ImageList(object):
def __init__(self, tensors, image_sizes):
self.tensors = tensors
self.image_sizes = image_sizes
def to(self, *args, **kwargs):
cast_tensor = self.tensors.to(*args, **kwargs)
return ImageList(cast_tensor, self.image_sizes)
def to_image_list(tensors, size_divisible=32):
# Preprocessing
if isinstance(tensors, Tensor) and size_divisible > 0:
tensors = [tensors]
if isinstance(tensors, ImageList):
return tensors
elif isinstance(tensors, Tensor):
# single tensor shape can be inferred
assert tensors.ndim == 4
image_sizes = [tensor.shape[-2:] for tensor in tensors]
return ImageList(tensors, image_sizes)
elif isinstance(tensors, (tuple, list)):
max_size = tuple(max(s) for s in zip(*[img.shape for img in tensors]))
if size_divisible > 0:
stride = size_divisible
max_size = list(max_size)
max_size[1] = int(math.ceil(max_size[1] / stride) * stride)
max_size[2] = int(math.ceil(max_size[2] / stride) * stride)
max_size = tuple(max_size)
batch_shape = (len(tensors),) + max_size
batched_imgs = np.zeros(batch_shape, dtype=tensors[0].dtype.np)
for img, pad_img in zip(tensors, batched_imgs):
pad_img[: img.shape[0], : img.shape[1], : img.shape[2]] += img.numpy()
batched_imgs = Tensor(batched_imgs)
image_sizes = [im.shape[-2:] for im in tensors]
return ImageList(batched_imgs, image_sizes)
else:
raise TypeError("Unsupported type for to_image_list: {}".format(type(tensors)))
class MaskRCNN:
def __init__(self, backbone: ResNet):
self.backbone = ResNetFPN(backbone, out_channels=256)
self.rpn = RPN(self.backbone.out_channels)
self.roi_heads = RoIHeads(self.backbone.out_channels)
def load_from_pretrained(self):
fn = Path('./') / "weights/maskrcnn.pt"
download_file("https://download.pytorch.org/models/maskrcnn/e2e_mask_rcnn_R_50_FPN_1x.pth", fn)
state_dict = torch_load(fn)['model']
loaded_keys = []
for k, v in state_dict.items():
if "module." in k:
k = k.replace("module.", "")
if "stem." in k:
k = k.replace("stem.", "")
if "fpn_inner" in k:
block_index = int(re.search(r"fpn_inner(\d+)", k).group(1))
k = re.sub(r"fpn_inner\d+", f"inner_blocks.{block_index - 1}", k)
if "fpn_layer" in k:
block_index = int(re.search(r"fpn_layer(\d+)", k).group(1))
k = re.sub(r"fpn_layer\d+", f"layer_blocks.{block_index - 1}", k)
loaded_keys.append(k)
get_child(self, k).assign(v.numpy()).realize()
return loaded_keys
def __call__(self, images):
images = to_image_list(images)
features = self.backbone(images.tensors)
proposals, _ = self.rpn(images, features)
x, result, _ = self.roi_heads(features, proposals)
return result
if __name__ == '__main__':
resnet = resnet = ResNet(50, num_classes=None, stride_in_1x1=True)
model = MaskRCNN(backbone=resnet)
model.load_from_pretrained()