File size: 7,512 Bytes
9231ab9
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
from typing import List, Union

from ..utils import (
    add_end_docstrings,
    is_tf_available,
    is_torch_available,
    is_vision_available,
    logging,
    requires_backends,
)
from .base import PIPELINE_INIT_ARGS, Pipeline


if is_vision_available():
    from PIL import Image

    from ..image_utils import load_image

if is_tf_available():
    from ..models.auto.modeling_tf_auto import TF_MODEL_FOR_VISION_2_SEQ_MAPPING_NAMES

if is_torch_available():
    import torch

    from ..models.auto.modeling_auto import MODEL_FOR_VISION_2_SEQ_MAPPING_NAMES

logger = logging.get_logger(__name__)


@add_end_docstrings(PIPELINE_INIT_ARGS)
class ImageToTextPipeline(Pipeline):
    """
    Image To Text pipeline using a `AutoModelForVision2Seq`. This pipeline predicts a caption for a given image.

    Example:

    ```python
    >>> from transformers import pipeline

    >>> captioner = pipeline(model="ydshieh/vit-gpt2-coco-en")
    >>> captioner("https://huggingface.co/datasets/Narsil/image_dummy/raw/main/parrots.png")
    [{'generated_text': 'two birds are standing next to each other '}]
    ```

    Learn more about the basics of using a pipeline in the [pipeline tutorial](../pipeline_tutorial)

    This image to text pipeline can currently be loaded from pipeline() using the following task identifier:
    "image-to-text".

    See the list of available models on
    [huggingface.co/models](https://huggingface.co/models?pipeline_tag=image-to-text).
    """

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        requires_backends(self, "vision")
        self.check_model_type(
            TF_MODEL_FOR_VISION_2_SEQ_MAPPING_NAMES if self.framework == "tf" else MODEL_FOR_VISION_2_SEQ_MAPPING_NAMES
        )

    def _sanitize_parameters(self, max_new_tokens=None, generate_kwargs=None, prompt=None, timeout=None):
        forward_kwargs = {}
        preprocess_params = {}

        if prompt is not None:
            preprocess_params["prompt"] = prompt
        if timeout is not None:
            preprocess_params["timeout"] = timeout

        if generate_kwargs is not None:
            forward_kwargs["generate_kwargs"] = generate_kwargs
        if max_new_tokens is not None:
            if "generate_kwargs" not in forward_kwargs:
                forward_kwargs["generate_kwargs"] = {}
            if "max_new_tokens" in forward_kwargs["generate_kwargs"]:
                raise ValueError(
                    "'max_new_tokens' is defined twice, once in 'generate_kwargs' and once as a direct parameter,"
                    " please use only one"
                )
            forward_kwargs["generate_kwargs"]["max_new_tokens"] = max_new_tokens
        return preprocess_params, forward_kwargs, {}

    def __call__(self, images: Union[str, List[str], "Image.Image", List["Image.Image"]], **kwargs):
        """
        Assign labels to the image(s) passed as inputs.

        Args:
            images (`str`, `List[str]`, `PIL.Image` or `List[PIL.Image]`):
                The pipeline handles three types of images:

                - A string containing a HTTP(s) link pointing to an image
                - A string containing a local path to an image
                - An image loaded in PIL directly

                The pipeline accepts either a single image or a batch of images.

            max_new_tokens (`int`, *optional*):
                The amount of maximum tokens to generate. By default it will use `generate` default.

            generate_kwargs (`Dict`, *optional*):
                Pass it to send all of these arguments directly to `generate` allowing full control of this function.
            timeout (`float`, *optional*, defaults to None):
                The maximum time in seconds to wait for fetching images from the web. If None, no timeout is set and
                the call may block forever.

        Return:
            A list or a list of list of `dict`: Each result comes as a dictionary with the following key:

            - **generated_text** (`str`) -- The generated text.
        """
        return super().__call__(images, **kwargs)

    def preprocess(self, image, prompt=None, timeout=None):
        image = load_image(image, timeout=timeout)

        if prompt is not None:
            if not isinstance(prompt, str):
                raise ValueError(
                    f"Received an invalid text input, got - {type(prompt)} - but expected a single string. "
                    "Note also that one single text can be provided for conditional image to text generation."
                )

            model_type = self.model.config.model_type

            if model_type == "git":
                model_inputs = self.image_processor(images=image, return_tensors=self.framework)
                input_ids = self.tokenizer(text=prompt, add_special_tokens=False).input_ids
                input_ids = [self.tokenizer.cls_token_id] + input_ids
                input_ids = torch.tensor(input_ids).unsqueeze(0)
                model_inputs.update({"input_ids": input_ids})

            elif model_type == "pix2struct":
                model_inputs = self.image_processor(images=image, header_text=prompt, return_tensors=self.framework)

            elif model_type != "vision-encoder-decoder":
                # vision-encoder-decoder does not support conditional generation
                model_inputs = self.image_processor(images=image, return_tensors=self.framework)
                text_inputs = self.tokenizer(prompt, return_tensors=self.framework)
                model_inputs.update(text_inputs)

            else:
                raise ValueError(f"Model type {model_type} does not support conditional text generation")

        else:
            model_inputs = self.image_processor(images=image, return_tensors=self.framework)

        if self.model.config.model_type == "git" and prompt is None:
            model_inputs["input_ids"] = None

        return model_inputs

    def _forward(self, model_inputs, generate_kwargs=None):
        # Git model sets `model_inputs["input_ids"] = None` in `preprocess` (when `prompt=None`). In batch model, the
        # pipeline will group them into a list of `None`, which fail `_forward`. Avoid this by checking it first.
        if (
            "input_ids" in model_inputs
            and isinstance(model_inputs["input_ids"], list)
            and all(x is None for x in model_inputs["input_ids"])
        ):
            model_inputs["input_ids"] = None

        if generate_kwargs is None:
            generate_kwargs = {}
        # FIXME: We need to pop here due to a difference in how `generation.py` and `generation.tf_utils.py`
        #  parse inputs. In the Tensorflow version, `generate` raises an error if we don't use `input_ids` whereas
        #  the PyTorch version matches it with `self.model.main_input_name` or `self.model.encoder.main_input_name`
        #  in the `_prepare_model_inputs` method.
        inputs = model_inputs.pop(self.model.main_input_name)
        model_outputs = self.model.generate(inputs, **model_inputs, **generate_kwargs)
        return model_outputs

    def postprocess(self, model_outputs):
        records = []
        for output_ids in model_outputs:
            record = {
                "generated_text": self.tokenizer.decode(
                    output_ids,
                    skip_special_tokens=True,
                )
            }
            records.append(record)
        return records