File size: 4,476 Bytes
e8aa256 |
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 |
# Copyright 2023 The HuggingFace Team. 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.
from typing import Optional, Tuple
import jax
import jax.numpy as jnp
from flax import linen as nn
from flax.core.frozen_dict import FrozenDict
from transformers import CLIPConfig, FlaxPreTrainedModel
from transformers.models.clip.modeling_flax_clip import FlaxCLIPVisionModule
def jax_cosine_distance(emb_1, emb_2, eps=1e-12):
norm_emb_1 = jnp.divide(emb_1.T, jnp.clip(jnp.linalg.norm(emb_1, axis=1), a_min=eps)).T
norm_emb_2 = jnp.divide(emb_2.T, jnp.clip(jnp.linalg.norm(emb_2, axis=1), a_min=eps)).T
return jnp.matmul(norm_emb_1, norm_emb_2.T)
class FlaxStableDiffusionSafetyCheckerModule(nn.Module):
config: CLIPConfig
dtype: jnp.dtype = jnp.float32
def setup(self):
self.vision_model = FlaxCLIPVisionModule(self.config.vision_config)
self.visual_projection = nn.Dense(self.config.projection_dim, use_bias=False, dtype=self.dtype)
self.concept_embeds = self.param("concept_embeds", jax.nn.initializers.ones, (17, self.config.projection_dim))
self.special_care_embeds = self.param(
"special_care_embeds", jax.nn.initializers.ones, (3, self.config.projection_dim)
)
self.concept_embeds_weights = self.param("concept_embeds_weights", jax.nn.initializers.ones, (17,))
self.special_care_embeds_weights = self.param("special_care_embeds_weights", jax.nn.initializers.ones, (3,))
def __call__(self, clip_input):
pooled_output = self.vision_model(clip_input)[1]
image_embeds = self.visual_projection(pooled_output)
special_cos_dist = jax_cosine_distance(image_embeds, self.special_care_embeds)
cos_dist = jax_cosine_distance(image_embeds, self.concept_embeds)
# increase this value to create a stronger `nfsw` filter
# at the cost of increasing the possibility of filtering benign image inputs
adjustment = 0.0
special_scores = special_cos_dist - self.special_care_embeds_weights[None, :] + adjustment
special_scores = jnp.round(special_scores, 3)
is_special_care = jnp.any(special_scores > 0, axis=1, keepdims=True)
# Use a lower threshold if an image has any special care concept
special_adjustment = is_special_care * 0.01
concept_scores = cos_dist - self.concept_embeds_weights[None, :] + special_adjustment
concept_scores = jnp.round(concept_scores, 3)
has_nsfw_concepts = jnp.any(concept_scores > 0, axis=1)
return has_nsfw_concepts
class FlaxStableDiffusionSafetyChecker(FlaxPreTrainedModel):
config_class = CLIPConfig
main_input_name = "clip_input"
module_class = FlaxStableDiffusionSafetyCheckerModule
def __init__(
self,
config: CLIPConfig,
input_shape: Optional[Tuple] = None,
seed: int = 0,
dtype: jnp.dtype = jnp.float32,
_do_init: bool = True,
**kwargs,
):
if input_shape is None:
input_shape = (1, 224, 224, 3)
module = self.module_class(config=config, dtype=dtype, **kwargs)
super().__init__(config, module, input_shape=input_shape, seed=seed, dtype=dtype, _do_init=_do_init)
def init_weights(self, rng: jax.Array, input_shape: Tuple, params: FrozenDict = None) -> FrozenDict:
# init input tensor
clip_input = jax.random.normal(rng, input_shape)
params_rng, dropout_rng = jax.random.split(rng)
rngs = {"params": params_rng, "dropout": dropout_rng}
random_params = self.module.init(rngs, clip_input)["params"]
return random_params
def __call__(
self,
clip_input,
params: dict = None,
):
clip_input = jnp.transpose(clip_input, (0, 2, 3, 1))
return self.module.apply(
{"params": params or self.params},
jnp.array(clip_input, dtype=jnp.float32),
rngs={},
)
|