# Tesseract OCR 5.5.1: lesson test 2026-10-11 (passed)

Cite: headlesson test:djrmwhe — Tesseract OCR 5.5.1, 2026-10-11: 8/8 lesson steps passed (operator record). On 2026-10-11, the headlesson operator ran all 8 steps of this lesson with Tesseract OCR 5.5.1 (macOS26.5.2 arm64; Homebrew tesseract 5.5.1 and tesseract-lang 4.1.0 already installed (not reinstalled; upstream latest is 5.5.3); poppler 26.04.0 for pdftoppm; self-made text page only), and all passed. The final Next step is advice and was not run. No independent check has been reviewed. This is the operator's own run, not a vendor claim. https://headlesson.com/tests/djrmwhe

Record test:djrmwhe. Question: Render a self-made text page to a PNG, OCR it with tesseract and check the recognized text.

## Answer

On 2026-10-11, the headlesson operator ran all 8 steps of this lesson with Tesseract OCR 5.5.1 (macOS26.5.2 arm64; Homebrew tesseract 5.5.1 and tesseract-lang 4.1.0 already installed (not reinstalled; upstream latest is 5.5.3); poppler 26.04.0 for pdftoppm; self-made text page only), and all passed. The final Next step is advice and was not run. No independent check has been reviewed. This is the operator's own run, not a vendor claim.

## Tested on

- Test date: 2026-10-11
- Record confirmed: 2026-10-11
- Version: 5.5.1
- Environment: macOS26.5.2 arm64; Homebrew tesseract 5.5.1 and tesseract-lang 4.1.0 already installed (not reinstalled; upstream latest is 5.5.3); poppler 26.04.0 for pdftoppm; self-made text page only
- Result: passed, 8/8 steps

## Lesson steps and what happened

- 1. [passed] command -v tesseract || brew install tesseract
- 2. [passed] tesseract --version
- 3. [passed] tesseract --list-langs
- 4. [passed] printf 'Invoice 2026-001\nTotal: 42 apples\n' > note.txt
- 5. [passed] cupsfilter -m application/pdf note.txt > note.pdf
- 6. [passed] pdftoppm -r 300 -png -singlefile note.pdf scan
- 7. [passed] tesseract scan.png out -l eng
- 8. [passed] grep -c 'Total: 42 apples' out.txt

## Next (advice, not tested)

Next: Agree with the user on the real images, their languages and the output format; check that the language codes appear in tesseract --list-langs, OCR one page with -l <lang> (add tsv to get word confidences), and compare a sample of the text with the image before processing the rest.

## Cautions recorded with the lesson

These notes come from the lesson. Some describe failures seen in tests; others are general cautions. Each one is not a separately tested result.

- The Homebrew tesseract formula contains only the eng and osd language data; other languages need brew install tesseract-lang.
- An unavailable language (for example -l xxx) printed "Failed loading language" and exited 1 in the test; check tesseract --list-langs first.
- The second argument is an output base name; tesseract scan.png out writes out.txt. Pass - as the output base to print to standard output.
- Low-resolution input is misread without an error; a 50 dpi render gave "Inyatce 2026" and exit 0 in the test, while a 300 dpi render was read correctly. Check the text, not only the exit code.
- Appending the config names tsv, hocr or pdf selects word-level TSV with positions and confidence, hOCR, or a searchable PDF with a text layer.
- Steps 4 and 5 use macOS cupsfilter and poppler's pdftoppm only to make a test image; any PNG of printed text works as input.
- Confirm: Check which images are read, which language data is used and where the output file is written (an existing out.txt is replaced), and spot-check the OCR text against the image before passing it to a downstream step.

## What this record does not show

- Not measured in this run: Tesseract 5.5.3 (the release current at test time).
- Not measured in this run: installing the language data from scratch.
- Not measured in this run: non-Latin scripts on real scans.
- Not measured in this run: photos, skewed or noisy scans.
- Not measured in this run: multi-page TIFF.
- Not measured in this run: the --psm and --oem choices.
- Not measured in this run: training.
- Whether an agent new to this tool can use it from this record alone (the operator wrote and ran the lesson).
- Comparisons between models or clients.
- Production use, accounts, or real customer data.
- Behaviour of the latest version (the test is tied to the version and date below).
- The final "Next" step is advice and was not part of the test.

## Primary record

Operator record: a past lesson trial (legacy). It is not claimed to meet level L1 of run-task-contract/0.1.0.

## Independent check

Independent check: not yet reviewed. (Whether an independent check exists has not been looked up for this record.)

## Evidence

A non-public test report exists and is not published, so third parties cannot check it directly.

## Retrieve over MCP

`headlesson_get id="app:tesseract" sections ["lesson","gotchas"]` on https://mcp.headlesson.com/mcp

## Source version

This page is built from the catalog record app:tesseract at revision 0a66d9cd024b. It is not rewritten when the current lesson changes; a new test gets a new record ID.

## Sources (lesson text at the fixed revision)

Each line names fields of this page (as JSON pointers into the .json version) and where they come from. Labels without a link are non-public sources. Fields not listed (such as test results) are the headlesson operator's own observations.

- /question, /next_advice, /cautions/items/5, /cautions/items/6: headlesson editorial judgement (checked 2026-10-11, inferred, editorial)
- /steps/0/step, /cautions/items/0: [https://formulae.brew.sh/formula/tesseract](https://formulae.brew.sh/formula/tesseract) (checked 2026-10-11, primary, third-party)
- /steps/1/step, /steps/2/step, /steps/3/step, /steps/4/step, /steps/5/step, /steps/6/step, /steps/7/step, /cautions/items/1, /cautions/items/2, /cautions/items/3: headlesson editorial judgement (checked 2026-10-11, primary, editorial)
- /cautions/items/4: [https://tesseract-ocr.github.io/tessdoc/Command-Line-Usage.html](https://tesseract-ocr.github.io/tessdoc/Command-Line-Usage.html) (checked 2026-10-11, primary, official)

## Corrections

None.

Page updated: 2026-10-13 (the date its content last changed).

要約（日本語）: Tesseract OCR の lesson を 2026-10-11 に headlesson の運営が 5.5.1 で試し、8/8 段が通った（passed、運営の実測で製品側の主張ではない）。この記録が示さないこと・独立確認の状況は本文のとおり。