torch_utils/ssd/ssd.py
2021-05-17 21:05:15 +09:00

165 lines
7.7 KiB
Python

import colorsys
import math
import numpy as np
import torch
import torch.nn as nn
from .box import check_rectangle
from ..layers import Conv2d
class SSD(nn.Module):
class Detector(nn.Module):
def __init__(self, input_features: int, output_features: int):
super().__init__()
self.conv = Conv2d(input_features, output_features, kernel_size=3, padding=1,
batch_norm=False, activation=None)
self.output = None
def forward(self, input_data: torch.Tensor) -> torch.Tensor:
self.output = self.conv(input_data).permute(0, 2, 3, 1)
return self.output
class DetectorMerge(nn.Module):
def __init__(self, location_dimmension: int):
super().__init__()
self.location_dim = location_dimmension
def forward(self, detector_outputs: torch.Tensor) -> torch.Tensor:
return torch.cat(
[detector_outputs[:, :, :self.location_dim],
torch.softmax(detector_outputs[:, :, self.location_dim:], dim=2)], dim=2)
class AnchorInfo:
def __init__(self, center: tuple[float, float], size: tuple[float],
index: int, layer_index: int, map_index: tuple[int, int], color_index: int,
ratio: float, size_factor: float):
self.index = index
self.layer_index = layer_index
self.map_index = map_index
self.color_index = color_index
self.ratio = ratio
self.size_factor = size_factor
self.center = center
self.size = size
self.box = check_rectangle(
center[0] - (size[0] / 2), center[1] - (size[1] / 2),
center[0] + (size[0] / 2), center[1] + (size[1] / 2))
def __repr__(self):
return (f'{self.__class__.__name__}'
f'(index:{self.index}, layer:{self.layer_index}, coord:{self.map_index}'
f', center:({self.center[0]:.03f}, {self.center[1]:.03f})'
f', size:({self.size[0]:.03f}, {self.size[1]:.03f})'
f', ratio:{self.ratio:.03f}, size_factor:{self.size_factor:.03f})'
f', y:[{self.box[0]:.03f}:{self.box[2]:.03f}]'
f', x:[{self.box[1]:.03f}:{self.box[3]:.03f}])')
def __array__(self):
return np.array([*self.center, *self.size])
def __init__(self, base_network: nn.Module, input_sample: torch.Tensor, classes: list[str],
location_dimmension: int, layer_channels: list[int], layer_box_ratios: list[float], layer_args: dict,
box_size_factors: list[float]):
super().__init__()
self.location_dim = location_dimmension
self.classes = ['none'] + classes
self.class_count = len(self.classes)
self.base_input_shape = input_sample.numpy().shape[1:]
self.base_network = base_network
sample_output = base_network(input_sample)
self.base_output_shape = list(sample_output.detach().numpy().shape)[-3:]
layer_convs: list[nn.Module] = []
layer_detectors: list[SSD.Detector] = []
last_feature_count = self.base_output_shape[0]
for layer_index, (output_features, kwargs) in enumerate(zip(layer_channels, layer_args)):
if 'disable' not in kwargs:
layer_convs.append(Conv2d(last_feature_count, output_features, **kwargs))
layer_detectors.append(SSD.Detector(
last_feature_count, (self.class_count + self.location_dim) * len(layer_box_ratios[layer_index])))
# layers.append(SSD.Layer(
# last_feature_count, output_features,
# (self.class_count + self.location_dim) * len(layer_box_ratios[layer_index]),
# **kwargs))
last_feature_count = output_features
self.layer_convs = nn.ModuleList(layer_convs)
self.layer_detectors = nn.ModuleList(layer_detectors)
self.merge = self.DetectorMerge(location_dimmension)
self.anchors_numpy, self.anchor_info, self.box_colors = self._create_anchors(
sample_output, self.layer_convs, self.layer_detectors, layer_box_ratios, box_size_factors,
input_sample.shape[3] / input_sample.shape[2])
self.anchors = torch.from_numpy(self.anchors_numpy)
def forward(self, input_data: torch.Tensor) -> torch.Tensor:
head = self.base_network(input_data)
detector_outputs = []
for layer_index, detector in enumerate(self.layer_detectors):
detector_out = detector(head)
detector_outputs.append(detector_out.reshape(
detector_out.size(0), -1, self.class_count + self.location_dim))
if layer_index < len(self.layer_convs):
head = self.layer_convs[layer_index](head)
detector_outputs = torch.cat(detector_outputs, 1)
return self.merge(detector_outputs)
# base_output = self.base_network(input_data)
# head = base_output
# outputs = []
# for layer in self.layers:
# head, detector_output = layer(head)
# outputs.append(detector_output.reshape(base_output.size(0), -1, self.class_count + self.location_dim))
# outputs = torch.cat(outputs, 1)
# return torch.cat(
# [outputs[:, :, :self.location_dim], torch.softmax(outputs[:, :, self.location_dim:], dim=2)], dim=2)
def _apply(self, fn):
super()._apply(fn)
self.anchors = fn(self.anchors)
return self
@staticmethod
def _create_anchors(
base_output: torch.Tensor, layers: nn.ModuleList, detectors: nn.ModuleList, layer_box_ratios: list[float],
box_size_factors: list[float], image_ratio: float) -> tuple[np.ndarray, np.ndarray, list[np.ndarray]]:
anchors = []
anchor_info: list[SSD.AnchorInfo] = []
box_colors: list[np.ndarray] = []
head = base_output
for layer_index, detector in enumerate(detectors):
detector_output = detector(head) # detector output shape : NCRSHW (Ratio, Size)
if layer_index < len(layers):
head = layers[layer_index](head)
detector_rows = detector_output.size()[1]
detector_cols = detector_output.size()[2]
color_index = 0
layer_ratios = layer_box_ratios[layer_index]
for index_y in range(detector_rows):
center_y = (index_y + 0.5) / detector_rows
for index_x in range(detector_cols):
center_x = (index_x + 0.5) / detector_cols
for ratio, size_factor in zip(layer_ratios, box_size_factors):
box_colors.append((np.asarray(colorsys.hsv_to_rgb(
color_index / len(layer_ratios), 1.0, 1.0)) * 255).astype(np.uint8))
color_index += 1
unit_box_size = size_factor / max(detector_rows, detector_cols)
anchor_width = unit_box_size * math.sqrt(ratio / image_ratio)
anchor_height = unit_box_size / math.sqrt(ratio / image_ratio)
anchor_info.append(SSD.AnchorInfo(
(center_y, center_x),
(anchor_height, anchor_width),
len(anchors),
layer_index,
(index_y, index_x),
len(box_colors) - 1,
ratio,
size_factor
))
anchors.append([center_y, center_x, anchor_height, anchor_width])
return np.asarray(anchors, dtype=np.float32), anchor_info, box_colors