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将扫描表单与系统记录核对

一个设备借用台会扫描每张手写借用单，并把信息录入系统。借用结束前，每份扫描件都要与录入的记录核对：纸面上的姓名、序列号和归还日期是否一致，是否已签名？

无误归还日期错误未签名
Lin Chen 的借用单Omar Haddad 的借用单Sara Novak 的借用单

工作原理​

代码把记录的每个字段转换成一句一眼就能核对的陈述，并按纸面上的写法来写（"The return date handwritten on the form is 12 March 2026"），再加一道关于签名栏的问题。四道判断题和扫描件放在同一次请求中。

字段核对状态
任一低于 0.3reject，列出未通过的字段
任一在 0.3 – 0.7review
全部 0.7 及以上accept

运行​

先下载一次示例包。caches/document_check.json 中录制的回答让脚本无需 API key 即可运行；加 --replay off 则改为调用免费托管 API。

Bash
curl -fLO https://valen-team.github.io/cookbook/valen-cookbook.zip
python -m zipfile -e valen-cookbook.zip .
cd valen-cookbook && python -m pip install -r requirements.txt
python document_check.py
python document_check.py --replay off --base-url https://api.valen-team.workers.dev/v1

代码​

document_check.py
"""Check a scanned loan form against the record typed into the system, field by field. Apache-2.0."""
from datetime import date
import json

from common import HERE, client, emit, image_bytes, image_input, parser, request

FIELDS = {"name": "borrower name", "serial": "serial number", "return_date": "return date"}


def written(field, value):
    # The record is stored in machine form; ask about it the way a person would read it on paper.
    if field != "return_date":
        return value
    day = date.fromisoformat(value)
    return f"{day.day} {day:%B %Y}"


def run(predict, record):
    questions = [{"name": field, "type": "predicate",
                  "instructions": f"The {label} handwritten on the form is {written(field, record[field])}."}
                 for field, label in FIELDS.items()]
    questions.append({"name": "signed", "type": "predicate",
                      "instructions": "The signature box contains a handwritten signature."})
    answers = request(predict, image_input(image_bytes(HERE / "media" / record["scan"])), questions)
    checks = {name: answers[name]["probability"] for name in [*FIELDS, "signed"]}
    failed = [name for name, p in checks.items() if p < 0.3]
    unclear = [name for name, p in checks.items() if 0.3 <= p < 0.7]
    status = "reject" if failed else "review" if unclear else "accept"
    return {"scan": record["scan"], "status": status, "failed": failed, "unclear": unclear, "checks": checks}


def main():
    args = parser(__doc__).parse_args()
    records = json.loads((HERE / "document_check_data.json").read_text())
    with client(args) as predict:
        emit([run(predict, record) for record in records], args)


if __name__ == "__main__":
    main()
document_check_data.json
[
  {"scan": "loan-a.jpg", "name": "Lin Chen", "serial": "CAM-20417", "return_date": "2026-03-12"},
  {"scan": "loan-b.jpg", "name": "Omar Haddad", "serial": "CAM-20562", "return_date": "2026-03-12"},
  {"scan": "loan-c.jpg", "name": "Sara Novak", "serial": "LAP-11873", "return_date": "2026-03-19"}
]

输出​

录制的输出
[
  {
    "scan": "loan-a.jpg",
    "status": "accept",
    "failed": [],
    "unclear": [],
    "checks": {
      "name": 0.9992125595012277,
      "serial": 0.9983302126024323,
      "return_date": 0.9976673179646833,
      "signed": 0.9990492985319737
    }
  },
  {
    "scan": "loan-b.jpg",
    "status": "reject",
    "failed": [
      "return_date"
    ],
    "unclear": [],
    "checks": {
      "name": 0.9986719510816103,
      "serial": 0.9984982673413811,
      "return_date": 0.007865409520616382,
      "signed": 0.997229301770541
    }
  },
  {
    "scan": "loan-c.jpg",
    "status": "reject",
    "failed": [
      "signed"
    ],
    "unclear": [],
    "checks": {
      "name": 0.9989126426472942,
      "serial": 0.9990923741991619,
      "return_date": 0.997633862429052,
      "signed": 0.006129618756955932
    }
  }
]

改成你自己的​

  • 用表单自身的写法询问记录内容：日期按书写的样子，姓名按签名的样子。
  • 对于长文档，用代码裁出每个字段区域，把裁剪图作为单独的请求发送。
  • 这里的表单是用手写字体为本教程生成的。