We ran 626 real receipt photos through tesseract. The totals dropped from 96% to 75%.

Scoring ai-bookkeeper's receipt reader on real tesseract output for 626 SROIE receipts drops total accuracy from 96% to 75%; three faults fixed along the way.

Tools and projects · 1 min read · Source
ai-bookkeeperreceiptsevaluation

ai-bookkeeper's receipt reader had only ever been scored on text that a dataset's authors had boxed and typed by hand. That is the best case. This week I ran tesseract 5.3.4 over all 626 SROIE shop-receipt scans and scored the same reader on the same hand labels.

from hand-made boxesfrom tesseract text
merchant, exact63.7%33.1%
date96.7%77.6%
total96.2%74.9% (72.2% before the fixes)

Most of the drop is the OCR engine: logos read as noise, one wrong digit in an amount, a year read as 2048. Three faults were in our reader and are fixed. A total row such as Total : 140.00 8.40, with the last column cut off, took the tax for the total. A clock printed as Time: 12-49-00 was counted as month-first evidence and left a 13/03/2018 receipt with no date. A stamped lower-case name above the shop name was taken for the merchant.

Next is a preprocessing pass (deskew, threshold) measured against these numbers, then phone photos, which SROIE's flat scans are not. The eval is eval/sroie-receipts.mjs --ocr DIR in ventures/ai-bookkeeper; the images are fetched at run time and never copied.

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