PyLaia / app.py
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Cache download model location, load images in L mode
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from uuid import uuid4
import gradio as gr
from laia.scripts.htr.decode_ctc import run as decode
from laia.common.arguments import CommonArgs, DataArgs, TrainerArgs, DecodeArgs
import sys
from tempfile import NamedTemporaryFile, mkdtemp
from pathlib import Path
from contextlib import redirect_stdout
import re
from huggingface_hub import snapshot_download
images = Path(mkdtemp())
IMAGE_ID_PATTERN = r"(?P<image_id>[-a-z0-9]{36})"
CONFIDENCE_PATTERN = r"(?P<confidence>[0-9.]+)" # For line
TEXT_PATTERN = r"\s*(?P<text>.*)\s*"
LINE_PREDICTION = re.compile(rf"{IMAGE_ID_PATTERN} {CONFIDENCE_PATTERN} {TEXT_PATTERN}")
models_name = ["Teklia/pylaia-rimes"]
MODELS = {}
DEFAULT_HEIGHT = 128
def get_width(image, height=DEFAULT_HEIGHT):
aspect_ratio = image.width / image.height
return height * aspect_ratio
def load_model(model_name):
if model_name not in MODELS:
MODELS[model_name] = Path(snapshot_download(model_name))
return MODELS[model_name]
def predict(model_name, input_img):
model_dir = load_model(model_name)
temperature = 2.0
batch_size = 1
weights_path = model_dir / "weights.ckpt"
syms_path = model_dir / "syms.txt"
language_model_params = {"language_model_weight": 1.0}
use_language_model = (model_dir / "tokens.txt").exists()
if use_language_model:
language_model_params.update(
{
"language_model_path": str(model_dir / "language_model.arpa.gz"),
"lexicon_path": str(model_dir / "lexicon.txt"),
"tokens_path": str(model_dir / "tokens.txt"),
}
)
common_args = CommonArgs(
checkpoint=str(weights_path.relative_to(model_dir)),
train_path=str(model_dir),
experiment_dirname="",
)
data_args = DataArgs(batch_size=batch_size, color_mode="L")
trainer_args = TrainerArgs(
# Disable progress bar else it messes with frontend display
progress_bar_refresh_rate=0
)
decode_args = DecodeArgs(
include_img_ids=True,
join_string="",
convert_spaces=True,
print_line_confidence_scores=True,
print_word_confidence_scores=False,
temperature=temperature,
use_language_model=use_language_model,
**language_model_params,
)
with NamedTemporaryFile() as pred_stdout, NamedTemporaryFile() as img_list:
image_id = uuid4()
# Resize image to 128 if bigger/smaller
input_img = input_img.resize((int(get_width(input_img)), DEFAULT_HEIGHT))
input_img.save(str(images / f"{image_id}.jpg"))
# Export image list
Path(img_list.name).write_text("\n".join([str(image_id)]))
# Capture stdout as that's where PyLaia outputs predictions
with redirect_stdout(open(pred_stdout.name, mode="w")):
decode(
syms=str(syms_path),
img_list=img_list.name,
img_dirs=[str(images)],
common=common_args,
data=data_args,
trainer=trainer_args,
decode=decode_args,
num_workers=1,
)
# Flush stdout to avoid output buffering
sys.stdout.flush()
predictions = Path(pred_stdout.name).read_text().strip().splitlines()
assert len(predictions) == 1
_, score, text = LINE_PREDICTION.match(predictions[0]).groups()
return input_img, {"text": text, "score": score}
gradio_app = gr.Interface(
predict,
inputs=[
gr.Dropdown(models_name, value=models_name[0], label="Models"),
gr.Image(
label="Upload an image of a line",
sources=["upload", "clipboard"],
type="pil",
height=DEFAULT_HEIGHT,
width=2000,
image_mode="L",
),
],
outputs=[
gr.Image(label="Processed Image"),
gr.JSON(label="Decoded text"),
],
examples=[
["Teklia/pylaia-rimes", str(filename)]
for filename in Path("examples").iterdir()
],
title="Decode the transcription of an image using a PyLaia model",
cache_examples=True,
)
if __name__ == "__main__":
gradio_app.launch()