Files
surya-ocr/tools.py
T
Fu DaiandClaude Opus 4.8 1a585693be Suya OCR API — vLLM-backed, OpenAI-compatible OCR service
FastAPI service wrapping the Surya-OCR-2 model (datalab-to) served through vLLM:
legacy /v1/api/ai/* endpoints, an OpenAI-compatible /v1/chat/completions endpoint,
a coalescing request batcher, a local OCR CLI, Docker packaging, multilingual
example outputs, and quantization/concurrency benchmarks.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-17 10:20:02 +04:00

243 lines
6.6 KiB
Python

import io
import tempfile
from typing import List
import pypdfium2
from surya.debug.draw import draw_polys_on_image, draw_bboxes_on_image
from PIL import Image
from surya.settings import settings
from vllm_tools import predictors_vllm, ocr_vllm
predictors = predictors_vllm
def rescale_bbox(bbox, source_size, target_size):
width_ratio = target_size[0] / source_size[0]
height_ratio = target_size[1] / source_size[1]
return [
bbox[0] * width_ratio,
bbox[1] * height_ratio,
bbox[2] * width_ratio,
bbox[3] * height_ratio,
]
def expand_bbox(bbox, margin=5):
return [
max(0, int(bbox[0]) - margin),
max(0, int(bbox[1]) - margin),
int(bbox[2]) + margin,
int(bbox[3]) + margin,
]
def page_counter(pdf_file):
doc = open_pdf(pdf_file)
doc_len = len(doc)
doc.close()
return doc_len
def ocr_errors(pdf_file, page_count, sample_len=512, max_samples=10, max_pages=15):
from pdftext.extraction import plain_text_output
with tempfile.NamedTemporaryFile(suffix=".pdf") as f:
f.write(pdf_file.getvalue())
f.seek(0)
# Sample the text from the middle of the PDF
page_middle = page_count // 2
page_range = range(
max(page_middle - max_pages, 0), min(page_middle + max_pages, page_count)
)
text = plain_text_output(f.name, page_range=page_range)
sample_gap = len(text) // max_samples
if len(text) == 0 or sample_gap == 0:
return "This PDF has no text or very little text", ["no text"]
if sample_gap < sample_len:
sample_gap = sample_len
# Split the text into samples for the model
samples = []
for i in range(0, len(text), sample_gap):
samples.append(text[i : i + sample_len])
results = predictors["ocr_error"](samples)
label = "This PDF has good text."
if results.labels.count("bad") / len(results.labels) > 0.2:
label = "This PDF may have garbled or bad OCR text."
return label, results.labels
def text_detection(img):
text_pred = predictors["detection"]([img])[0]
text_polygons = [p.polygon for p in text_pred.bboxes]
det_img = draw_polys_on_image(text_polygons, img.copy())
return det_img, text_pred
def layout_detection(img):
pred = predictors["layout"]([img])[0]
polygons = [p.polygon for p in pred.bboxes]
labels = [
f"{p.label}-{p.position}-{round(p.top_k[p.label], 2)}" for p in pred.bboxes
]
layout_img = draw_polys_on_image(
polygons, img.copy(), labels=labels, label_font_size=18
)
return layout_img, pred
def table_recognition(
img, highres_img, skip_table_detection: bool
):
if skip_table_detection:
layout_tables = [(0, 0, highres_img.size[0], highres_img.size[1])]
table_imgs = [highres_img]
else:
_, layout_pred = layout_detection(img)
layout_tables_lowres = [
line.bbox
for line in layout_pred.bboxes
if line.label in ["Table", "TableOfContents"]
]
table_imgs = []
layout_tables = []
for tb in layout_tables_lowres:
highres_bbox = rescale_bbox(tb, img.size, highres_img.size)
# Slightly expand the box
highres_bbox = expand_bbox(highres_bbox)
table_imgs.append(highres_img.crop(highres_bbox))
layout_tables.append(highres_bbox)
table_preds = predictors["table_rec"](table_imgs)
table_img = img.copy()
for results, table_bbox in zip(table_preds, layout_tables):
adjusted_bboxes = []
labels = []
colors = []
for item in results.cells:
adjusted_bboxes.append(
[
(item.bbox[0] + table_bbox[0]),
(item.bbox[1] + table_bbox[1]),
(item.bbox[2] + table_bbox[0]),
(item.bbox[3] + table_bbox[1]),
]
)
labels.append(item.label)
if "Row" in item.label:
colors.append("blue")
else:
colors.append("red")
table_img = draw_bboxes_on_image(
adjusted_bboxes,
highres_img,
labels=labels,
label_font_size=18,
color=colors,
)
return table_img, table_preds
# Function for OCR
def ocr(
img: Image.Image,
highres_img: Image.Image,
skip_text_detection: bool = False,
recognize_math: bool = True,
with_bboxes: bool = True,
):
return ocr_vllm(
img,
highres_img,
skip_text_detection=skip_text_detection,
recognize_math=recognize_math,
with_bboxes=with_bboxes,
)
def open_pdf(pdf_file):
stream = io.BytesIO(pdf_file.getvalue())
return pypdfium2.PdfDocument(stream)
def get_page_image(pdf_file, page_num, dpi=settings.IMAGE_DPI):
doc = open_pdf(pdf_file)
renderer = doc.render(
pypdfium2.PdfBitmap.to_pil,
page_indices=[page_num - 1],
scale=dpi / 72,
)
png = list(renderer)[0]
png_image = png.convert("RGB")
doc.close()
return png_image
def page_counter(pdf_file):
doc = open_pdf(pdf_file)
doc_len = len(doc)
doc.close()
return doc_len
import pandas as pd
def bbox_intersection(box1, box2):
x1 = max(box1[0], box2[0])
y1 = max(box1[1], box2[1])
x2 = min(box1[2], box2[2])
y2 = min(box1[3], box2[3])
if x1 < x2 and y1 < y2:
return (x1, y1, x2, y2)
else:
return None
def area_of_bbox(box):
return (box[2] - box[0]) * (box[3] - box[1])
def is_bbox_inside(box, parent_box):
interaction_box = bbox_intersection(box, parent_box)
if interaction_box is None:
return False
return area_of_bbox(interaction_box) / area_of_bbox(box) > 0.5
def center_of_bbox(box):
return ((box[0] + box[2]) / 2, (box[1] + box[3]) / 2)
def extract_text_from_image(image):
layout_predictor = predictors["layout"]
recognition_predictor = predictors["recognition"]
layout_prediction = layout_predictor([image])[0]
prediction = recognition_predictor([image], [layout_prediction], full_page=False)[0]
items = [
{
"text": block.html,
"position": block.reading_order,
"order_value": block.bbox[1],
}
for block in prediction.blocks
if not block.skipped and not block.error and block.html
]
if not items:
return ""
df = pd.DataFrame(items)
df = df.sort_values(by=['position', 'order_value'])
ds = df.groupby('position').apply(lambda x: " ".join(x['text'].tolist()))
full_text = "\n\n".join(ds.to_list())
return full_text