Remove vision OCR — use Tesseract-only pipeline for receipt parsing

The llama3.2-vision model was producing unreliable structured data
(wrong vendors, amounts, dates) making expense reports worse than
Tesseract + LLM extraction.  Removes _ocr_image_vision(), the
vision JSON fast path in _parse_receipt_text(), _match_category(),
and the vision_ocr_model config setting entirely.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
This commit is contained in:
Carlos Garcia
2026-05-20 22:32:26 -04:00
parent ec6b41943f
commit 0320591344
4 changed files with 4 additions and 247 deletions

View File

@@ -317,30 +317,6 @@ class ExpensesAgent(BaseAgent):
return None
@staticmethod
def _match_category(category: str, expense_products: list) -> str:
"""Map a vision-model category label to the nearest expense product name.
Tries exact/substring match first, then a fuzzy SequenceMatcher pass.
Returns empty string when no reasonable match is found.
"""
if not expense_products or not category:
return ''
cat = category.lower().strip()
# Exact or substring match
for p in expense_products:
name = p['name'].lower()
if cat == name or cat in name or name in cat:
return p['name']
# Fuzzy fallback (ratio >= 0.4)
names_lower = [p['name'].lower() for p in expense_products]
matches = difflib.get_close_matches(cat, names_lower, n=1, cutoff=0.4)
if matches:
for p in expense_products:
if p['name'].lower() == matches[0]:
return p['name']
return ''
async def _parse_receipt_text(self, text: str, filename: str,
expense_products: list = None,
date_hint: str = None) -> dict:
@@ -348,35 +324,7 @@ class ExpensesAgent(BaseAgent):
fallback = {'vendor': filename, 'amount': 0.0,
'date': date_hint or today, 'time': None, 'product_name': ''}
# ── Fast path: vision model already returned structured JSON ──────────
# receipt_parser._ocr_image_vision() returns a JSON string directly
# when a vision model is configured. Skip the second LLM call entirely.
stripped = (text or '').strip()
if stripped.startswith('{'):
try:
data = json.loads(stripped)
if 'amount' in data:
logger.debug('expenses_agent: using vision pre-extracted JSON for %s', filename)
# Map the vision category label → expense product name
product_name = self._match_category(
data.get('category', ''), expense_products or [])
# Vision model sometimes returns the string "null" instead
# of JSON null — normalise both fields.
_NULL = (None, 'null', 'None', '')
raw_time = data.get('time')
time_val = None if raw_time in _NULL else str(raw_time)
raw_date = data.get('date')
date_val = None if raw_date in _NULL else str(raw_date)
return {
'vendor': str(data.get('vendor') or filename),
'amount': float(data.get('amount', 0.0)),
'date': date_val or date_hint or today,
'time': time_val,
'product_name': product_name,
}
except (json.JSONDecodeError, ValueError, TypeError):
pass # not clean JSON — fall through to LLM path
ocr_failed = not stripped or stripped.startswith('[')
product_list = ''

View File

@@ -16,10 +16,6 @@ class Settings(BaseSettings):
ollama_model: str = 'activeblue-chat'
ollama_timeout: int = 300
ollama_max_concurrent: int = 2
# Set to a vision-capable model (e.g. llama3.2-vision:11b) to use
# vision OCR for receipt images instead of Tesseract. Leave empty
# to keep the Tesseract pipeline.
vision_ocr_model: str = ''
# Anthropic / Claude
anthropic_api_key: str = ''

View File

@@ -80,121 +80,10 @@ def _extract_zip(zip_filename: str, data: bytes) -> list[dict]:
def _ocr_image(data: bytes, filename: str) -> str:
"""Extract text from a receipt image.
Tries vision-model OCR first when VISION_OCR_MODEL is configured,
then falls back to the Tesseract pipeline.
"""
from agent_service.config import get_settings
settings = get_settings()
if settings.vision_ocr_model:
result = _ocr_image_vision(data, filename,
settings.ollama_url,
settings.vision_ocr_model)
if result:
return result
logger.warning('Vision OCR returned empty for %s — falling back to Tesseract', filename)
"""Extract text from a receipt image using Tesseract."""
return _ocr_image_tesseract(data, filename)
def _ocr_image_vision(data: bytes, filename: str, ollama_url: str, model: str) -> str:
"""Use an Ollama vision model to extract receipt data directly as JSON.
Returns a JSON string {vendor, amount, date, time, category} so the
expenses agent can skip the second LLM extraction step entirely.
Returns empty string on any failure so the caller falls back to Tesseract.
"""
import json as _json
import re as _re
def _repair_json(s: str) -> str:
"""Fix the most common LLM JSON formatting mistakes.
Handles:
- trailing commas before } or ] → {"a":1,} becomes {"a":1}
- single-quoted strings → {'a':'b'} becomes {"a":"b"}
- unquoted string keys → {a: "b"} becomes {"a": "b"}
"""
# trailing commas
s = _re.sub(r',\s*([}\]])', r'\1', s)
# single-quoted strings (careful around apostrophes in values)
s = _re.sub(r"'([^']*)'", r'"\1"', s)
# unquoted keys: word characters before a colon
s = _re.sub(r'(?<!["\w])(\w+)\s*:', r'"\1":', s)
return s
try:
import ollama as _ollama
client = _ollama.Client(host=ollama_url)
response = client.chat(
model=model,
format='json', # Ollama JSON mode — forces syntactically valid output
messages=[{
'role': 'user',
'content': (
'You are a receipt data extractor. '
'Read this receipt image and extract the following fields. '
'Copy values EXACTLY as printed — do NOT guess, infer, or '
'invent values you cannot clearly see.\n\n'
'Fields to extract:\n'
'- vendor: the store or restaurant name exactly as printed; '
'empty string if not clearly visible\n'
'- amount: the FINAL total the customer paid; find a line '
'labeled "Total", "Grand Total", "Amount Due", or "Balance Due"; '
'copy the number exactly; do NOT use subtotal, tax, or tip; '
'return 0 if no clearly labeled final total is visible\n'
'- date: transaction date in YYYY-MM-DD format; '
'null if not clearly visible\n'
'- time: transaction time in HH:MM 24-hour format; '
'null if not clearly visible\n'
'- category: one of: meals, fuel, hotel, office, transport, other\n\n'
'Return ONLY a valid JSON object, no commentary, no markdown:\n'
'{"vendor":"...","amount":0.00,"date":"YYYY-MM-DD or null",'
'"time":"HH:MM or null","category":"..."}'
),
'images': [data],
}],
)
if isinstance(response, dict):
raw = (response.get('message', {}).get('content') or '').strip()
else:
raw = (response.message.content or '').strip()
# Must contain a JSON object, not prose
first, last = raw.find('{'), raw.rfind('}')
if first == -1 or last <= first:
logger.warning('Vision OCR %s: model returned prose, falling back to Tesseract',
filename)
return ''
json_str = raw[first:last + 1]
# Parse — on failure attempt common repairs then retry once
try:
parsed = _json.loads(json_str)
except _json.JSONDecodeError as json_err:
repaired = _repair_json(json_str)
try:
parsed = _json.loads(repaired)
logger.debug('Vision OCR %s: JSON repaired successfully', filename)
except _json.JSONDecodeError:
logger.warning('Vision OCR %s: JSON parse failed (%s), falling back',
filename, json_err)
return ''
if 'amount' not in parsed:
logger.warning('Vision OCR %s: JSON missing amount field, falling back', filename)
return ''
logger.debug('Vision OCR %s (%s): extracted JSON ok', filename, model)
# Re-serialise so downstream always gets clean, canonical JSON
return _json.dumps(parsed)
except ImportError:
logger.warning('ollama package not installed — vision OCR unavailable for %s', filename)
return ''
except Exception as exc:
logger.warning('Vision OCR failed for %s: %s', filename, exc)
return ''
def _ocr_image_tesseract(data: bytes, filename: str) -> str:
"""Tesseract-based OCR pipeline (fallback)."""
try:

View File

@@ -423,88 +423,12 @@ async def test_act_no_employee_returns_empty_and_escalates():
# ---------------------------------------------------------------------------
# _match_category
# ---------------------------------------------------------------------------
class TestMatchCategory:
PRODUCTS = [
{'id': 1, 'name': 'Meals'},
{'id': 2, 'name': 'Fuel'},
{'id': 3, 'name': 'Hotel'},
{'id': 4, 'name': 'Office Supplies'},
{'id': 5, 'name': 'Transport'},
{'id': 6, 'name': 'Other'},
]
def test_exact_match(self):
assert ExpensesAgent._match_category('Meals', self.PRODUCTS) == 'Meals'
def test_case_insensitive(self):
assert ExpensesAgent._match_category('meals', self.PRODUCTS) == 'Meals'
assert ExpensesAgent._match_category('FUEL', self.PRODUCTS) == 'Fuel'
def test_substring_match(self):
# 'office' is a substring of 'Office Supplies'
assert ExpensesAgent._match_category('office', self.PRODUCTS) == 'Office Supplies'
def test_fuzzy_match(self):
# 'transport' is close to 'Transport'
assert ExpensesAgent._match_category('transport', self.PRODUCTS) == 'Transport'
def test_no_match_returns_empty(self):
assert ExpensesAgent._match_category('zxqwerty', self.PRODUCTS) == ''
def test_empty_category(self):
assert ExpensesAgent._match_category('', self.PRODUCTS) == ''
def test_empty_products(self):
assert ExpensesAgent._match_category('meals', []) == ''
# ---------------------------------------------------------------------------
# _parse_receipt_text — vision JSON fast path
# _parse_receipt_text — LLM extraction path
# ---------------------------------------------------------------------------
@pytest.mark.asyncio
async def test_parse_vision_json_fast_path():
"""When text is pre-extracted JSON from vision model, skip LLM call."""
agent = _make_agent()
agent._llm.submit = AsyncMock() # should NOT be called
vision_json = ('{"vendor":"McDonald\'s","amount":12.50,'
'"date":"2026-05-09","time":"13:30","category":"meals"}')
products = [{'id': 1, 'name': 'Meals'}, {'id': 2, 'name': 'Fuel'}]
result = await agent._parse_receipt_text(vision_json, 'receipt.jpg',
expense_products=products)
assert result['vendor'] == "McDonald's"
assert result['amount'] == 12.50
assert result['date'] == '2026-05-09'
assert result['time'] == '13:30'
assert result['product_name'] == 'Meals'
agent._llm.submit.assert_not_called()
@pytest.mark.asyncio
async def test_parse_vision_json_null_time():
"""Vision model may return the string 'null' for time — normalise to None."""
agent = _make_agent()
agent._llm.submit = AsyncMock()
vision_json = '{"vendor":"Shell","amount":45.00,"date":"2026-05-09","time":"null","category":"fuel"}'
products = [{'id': 1, 'name': 'Meals'}, {'id': 2, 'name': 'Fuel'}]
result = await agent._parse_receipt_text(vision_json, 'shell.jpg',
expense_products=products)
assert result['time'] is None
assert result['product_name'] == 'Fuel'
agent._llm.submit.assert_not_called()
@pytest.mark.asyncio
async def test_parse_non_json_text_falls_through_to_llm():
"""Plain OCR text (not JSON) should go through the LLM extraction path."""
async def test_parse_plain_ocr_text_uses_llm():
"""Plain OCR text should go through the LLM extraction path."""
agent = _make_agent()
llm_resp = MagicMock()
llm_resp.content = '{"vendor":"Acme","amount":9.99,"date":"2026-05-09","time":null,"product_name":"Meals"}'