SRG2classic further re-integration

This commit is contained in:
James Betker 2020-11-10 16:06:14 -07:00
parent 9e2c96ad5d
commit 4e5ba61ae7

View File

@ -2,201 +2,18 @@ import os
import torch import torch
import torchvision import torchvision
from matplotlib import cm
from torch import nn from torch import nn
import torch.nn.functional as F import torch.nn.functional as F
import functools import functools
from collections import OrderedDict from collections import OrderedDict
from torch.nn import init from models.archs.SwitchedResidualGenerator_arch import HalvingProcessingBlock, ConfigurableSwitchComputer
from models.archs.arch_util import ConvBnLelu, ConvGnSilu, ExpansionBlock, MultiConvBlock
from models.archs.arch_util import ConvBnLelu, ConvGnSilu from switched_conv.switched_conv import BareConvSwitch, AttentionNorm
from utils.util import checkpoint from utils.util import checkpoint
def initialize_weights(net_l, scale=1):
if not isinstance(net_l, list):
net_l = [net_l]
for net in net_l:
for m in net.modules():
if isinstance(m, nn.Conv2d) or isinstance(m, nn.Conv3d):
init.kaiming_normal_(m.weight, a=0, mode='fan_in')
m.weight.data *= scale # for residual block
if m.bias is not None:
m.bias.data.zero_()
elif isinstance(m, nn.Linear):
init.kaiming_normal_(m.weight, a=0, mode='fan_in')
m.weight.data *= scale
if m.bias is not None:
m.bias.data.zero_()
elif isinstance(m, nn.BatchNorm2d):
init.constant_(m.weight, 1)
init.constant_(m.bias.data, 0.0)
class AttentionNorm(nn.Module):
def __init__(self, group_size, accumulator_size=128):
super(AttentionNorm, self).__init__()
self.accumulator_desired_size = accumulator_size
self.group_size = group_size
# These are all tensors so that they get saved with the graph.
self.accumulator = nn.Parameter(torch.zeros(accumulator_size, group_size), requires_grad=False)
self.accumulator_index = nn.Parameter(torch.zeros(1, dtype=torch.long, device='cpu'), requires_grad=False)
self.accumulator_filled = nn.Parameter(torch.zeros(1, dtype=torch.bool, device='cpu'), requires_grad=False)
# Returns tensor of shape (group,) with a normalized mean across the accumulator in the range [0,1]. The intent
# is to divide your inputs by this value.
def compute_buffer_norm(self):
if self.accumulator_filled:
return torch.mean(self.accumulator, dim=0)
else:
return torch.ones(self.group_size, device=self.accumulator.device)
def add_norm_to_buffer(self, x):
flat = x.sum(dim=[0, 1, 2], keepdim=True)
norm = flat / torch.mean(flat)
# This often gets reset in GAN mode. We *never* want gradient accumulation in this parameter.
self.accumulator.requires_grad = False
self.accumulator[self.accumulator_index] = norm.detach()
self.accumulator_index += 1
if self.accumulator_index >= self.accumulator_desired_size:
self.accumulator_index *= 0
self.accumulator_filled |= True
# Input into forward is an attention tensor of shape (batch,width,height,groups)
def forward(self, x: torch.Tensor):
assert len(x.shape) == 4
# Push the accumulator to the right device on the first iteration.
if self.accumulator.device != x.device:
self.accumulator = self.accumulator.to(x.device)
self.add_norm_to_buffer(x)
norm = self.compute_buffer_norm()
x = x / norm
# Need to re-normalize x so that the groups dimension sum to 1, just like when it was fed in.
groups_sum = x.sum(dim=3, keepdim=True)
return x / groups_sum
class BareConvSwitch(nn.Module):
"""
Initializes the ConvSwitch.
initial_temperature: The initial softmax temperature of the attention mechanism. For training from scratch, this
should be set to a high number, for example 30.
attention_norm: If specified, the AttentionNorm layer applied immediately after Softmax.
"""
def __init__(
self,
initial_temperature=1,
attention_norm=None
):
super(BareConvSwitch, self).__init__()
self.softmax = nn.Softmax(dim=-1)
self.temperature = initial_temperature
self.attention_norm = attention_norm
initialize_weights(self)
def set_attention_temperature(self, temp):
self.temperature = temp
# SwitchedConv.forward takes these arguments;
# conv_group: List of inputs (len=n) to the switch, each with shape (b,f,w,h)
# conv_attention: Attention computation as an output from a conv layer, of shape (b,n,w,h). Before softmax
# output_attention_weights: If True, post-softmax attention weights are returned.
def forward(self, conv_group, conv_attention, output_attention_weights=False):
# Stack up the conv_group input first and permute it to (batch, width, height, filter, groups)
conv_outputs = torch.stack(conv_group, dim=0).permute(1, 3, 4, 2, 0)
conv_attention = conv_attention.permute(0, 2, 3, 1)
conv_attention = self.softmax(conv_attention / self.temperature)
if self.attention_norm:
conv_attention = self.attention_norm(conv_attention)
# conv_outputs shape: (batch, width, height, filters, groups)
# conv_attention shape: (batch, width, height, groups)
# We want to format them so that we can matmul them together to produce:
# desired shape: (batch, width, height, filters)
# Note: conv_attention will generally be cast to float32 regardless of the input type, so cast conv_outputs to
# float32 as well to match it.
if self.training:
# Doing it all in one op is substantially faster - better for training.
attention_result = torch.einsum(
"...ij,...j->...i", [conv_outputs.float(), conv_attention]
)
else:
# eval_mode substantially reduces the GPU memory required to compute the attention result by performing the
# attention multiplications one at a time. This is probably necessary for large images and attention breadths.
attention_result = conv_outputs[:, :, :, :, 0] * conv_attention[:, :, :, 0].unsqueeze(dim=-1)
for i in range(1, conv_attention.shape[-1]):
attention_result += conv_outputs[:, :, :, :, i] * conv_attention[:, :, :, i].unsqueeze(dim=-1)
# Remember to shift the filters back into the expected slot.
if output_attention_weights:
return attention_result.permute(0, 3, 1, 2), conv_attention
else:
return attention_result.permute(0, 3, 1, 2)
class MultiConvBlock(nn.Module):
def __init__(self, filters_in, filters_mid, filters_out, kernel_size, depth, scale_init=1.0, norm=False, weight_init_factor=1):
assert depth >= 2
super(MultiConvBlock, self).__init__()
self.noise_scale = nn.Parameter(torch.full((1,), fill_value=.01))
self.bnconvs = nn.ModuleList([ConvBnLelu(filters_in, filters_mid, kernel_size, norm=norm, bias=False, weight_init_factor=weight_init_factor)] +
[ConvBnLelu(filters_mid, filters_mid, kernel_size, norm=norm, bias=False, weight_init_factor=weight_init_factor) for i in range(depth - 2)] +
[ConvBnLelu(filters_mid, filters_out, kernel_size, activation=False, norm=False, bias=False, weight_init_factor=weight_init_factor)])
self.scale = nn.Parameter(torch.full((1,), fill_value=scale_init))
self.bias = nn.Parameter(torch.zeros(1), requires_grad=False)
def forward(self, x, noise=None):
if noise is not None:
noise = noise * self.noise_scale
x = x + noise
for m in self.bnconvs:
x = m.forward(x)
return x * self.scale + self.bias
# VGG-style layer with Conv(stride2)->BN->Activation->Conv->BN->Activation
# Doubles the input filter count.
class HalvingProcessingBlock(nn.Module):
def __init__(self, filters):
super(HalvingProcessingBlock, self).__init__()
self.bnconv1 = ConvGnSilu(filters, filters * 2, stride=2, norm=False, bias=False)
self.bnconv2 = ConvGnSilu(filters * 2, filters * 2, norm=True, bias=False)
def forward(self, x):
x = self.bnconv1(x)
return self.bnconv2(x)
# Block that upsamples 2x and reduces incoming filters by 2x. It preserves structure by taking a passthrough feed
# along with the feature representation.
class ExpansionBlock(nn.Module):
def __init__(self, filters_in, filters_out=None, block=ConvGnSilu):
super(ExpansionBlock, self).__init__()
if filters_out is None:
filters_out = filters_in // 2
self.decimate = block(filters_in, filters_out, kernel_size=1, bias=False, activation=False, norm=True)
self.process_passthrough = block(filters_out, filters_out, kernel_size=3, bias=True, activation=False, norm=True)
self.conjoin = block(filters_out*2, filters_out, kernel_size=3, bias=False, activation=True, norm=False)
self.process = block(filters_out, filters_out, kernel_size=3, bias=False, activation=True, norm=True)
# input is the feature signal with shape (b, f, w, h)
# passthrough is the structure signal with shape (b, f/2, w*2, h*2)
# output is conjoined upsample with shape (b, f/2, w*2, h*2)
def forward(self, input, passthrough):
x = F.interpolate(input, scale_factor=2, mode="nearest")
x = self.decimate(x)
p = self.process_passthrough(passthrough)
x = self.conjoin(torch.cat([x, p], dim=1))
return self.process(x)
# This is a classic u-net architecture with the goal of assigning each individual pixel an individual transform # This is a classic u-net architecture with the goal of assigning each individual pixel an individual transform
# switching set. # switching set.
class ConvBasisMultiplexer(nn.Module): class ConvBasisMultiplexer(nn.Module):
@ -231,50 +48,6 @@ class ConvBasisMultiplexer(nn.Module):
return x return x
class ConfigurableSwitchComputer(nn.Module):
def __init__(self, base_filters, multiplexer_net, pre_transform_block, transform_block, transform_count, init_temp=20,
add_scalable_noise_to_transforms=False):
super(ConfigurableSwitchComputer, self).__init__()
tc = transform_count
self.multiplexer = multiplexer_net(tc)
self.pre_transform = pre_transform_block()
self.transforms = nn.ModuleList([transform_block() for _ in range(transform_count)])
self.add_noise = add_scalable_noise_to_transforms
self.noise_scale = nn.Parameter(torch.full((1,), float(1e-3)))
# And the switch itself, including learned scalars
self.switch = BareConvSwitch(initial_temperature=init_temp, attention_norm=AttentionNorm(transform_count, accumulator_size=16 * transform_count))
self.switch_scale = nn.Parameter(torch.full((1,), float(1)))
self.post_switch_conv = ConvBnLelu(base_filters, base_filters, norm=False, bias=True)
# The post_switch_conv gets a low scale initially. The network can decide to magnify it (or not)
# depending on its needs.
self.psc_scale = nn.Parameter(torch.full((1,), float(.1)))
def forward(self, x, output_attention_weights=True):
identity = x
if self.add_noise:
rand_feature = torch.randn_like(x) * self.noise_scale
x = x + rand_feature
x = self.pre_transform(x)
xformed = [t.forward(x) for t in self.transforms]
m = self.multiplexer(identity)
outputs, attention = self.switch(xformed, m, True)
outputs = identity + outputs * self.switch_scale
outputs = outputs + self.post_switch_conv(outputs) * self.psc_scale
if output_attention_weights:
return outputs, attention
else:
return outputs
def set_temperature(self, temp):
self.switch.set_attention_temperature(temp)
def compute_attention_specificity(att_weights, topk=3): def compute_attention_specificity(att_weights, topk=3):
att = att_weights.detach() att = att_weights.detach()
vals, indices = torch.topk(att, topk, dim=-1) vals, indices = torch.topk(att, topk, dim=-1)
@ -347,7 +120,7 @@ class ConfigurableSwitchedResidualGenerator2(nn.Module):
multiplx_fn = functools.partial(ConvBasisMultiplexer, transformation_filters, switch_filters, switch_reductions, switch_processing_layers, trans_counts) multiplx_fn = functools.partial(ConvBasisMultiplexer, transformation_filters, switch_filters, switch_reductions, switch_processing_layers, trans_counts)
pretransform_fn = functools.partial(ConvBnLelu, transformation_filters, transformation_filters, norm=False, bias=False, weight_init_factor=.1) pretransform_fn = functools.partial(ConvBnLelu, transformation_filters, transformation_filters, norm=False, bias=False, weight_init_factor=.1)
transform_fn = functools.partial(MultiConvBlock, transformation_filters, int(transformation_filters * 1.5), transformation_filters, kernel_size=trans_kernel_sizes, depth=trans_layers, weight_init_factor=.1) transform_fn = functools.partial(MultiConvBlock, transformation_filters, int(transformation_filters * 1.5), transformation_filters, kernel_size=trans_kernel_sizes, depth=trans_layers, weight_init_factor=.1)
switches.append(ConfigurableSwitchComputer(transformation_filters, multiplx_fn, switches.append(ConfigurableSwitchComputer(transformation_filters, multiplx_fn, attention_norm=True,
pre_transform_block=pretransform_fn, transform_block=transform_fn, pre_transform_block=pretransform_fn, transform_block=transform_fn,
transform_count=trans_counts, init_temp=initial_temp, transform_count=trans_counts, init_temp=initial_temp,
add_scalable_noise_to_transforms=add_scalable_noise_to_transforms)) add_scalable_noise_to_transforms=add_scalable_noise_to_transforms))
@ -412,10 +185,11 @@ class ConfigurableSwitchedResidualGenerator2(nn.Module):
class Interpolate(nn.Module): class Interpolate(nn.Module):
def __init__(self, factor): def __init__(self, factor, mode="nearest"):
super(Interpolate, self).__init__() super(Interpolate, self).__init__()
self.factor = factor self.factor = factor
self.mode = mode
def forward(self, x): def forward(self, x):
return F.interpolate(x, scale_factor=self.factor) return F.interpolate(x, scale_factor=self.factor, mode=self.mode)