Quick summary (tl;dr)

• macOS: Install via Homebrew (`brew install tesseract` + `brew install tesseract-lang` for extra languages) or download prebuilt libs (MBS offers lib bundles). Then call MBS("OCR.Load"; "/opt/homebrew/lib/libtesseract.4.dylib") (or path where Homebrew installed libs).
• Linux (Debian/Ubuntu): Install libraries and language files with apt: sudo apt-get install libtesseract5 tesseract-ocr-lang. Then call MBS("OCR.Load"; "libtesseract.so.5") (and load leptonica first if required).
• Windows: Use a community build/installer (UB-Mannheim and similar). Place DLLs in program folder and call MBS("Process.SetCurrentDirectory"; "C:\Program Files\Tesseract-OCR") & MBS("OCR.Load"; "libtesseract-4.dll").
• Important: Tesseract library version must match tessdata files (wrong combinations can crash). When using Tesseract 4.x+ with MBS, prefer OCR.Load to explicitly load newer runtimes.

Why explicit loading matters (MBS plugin)

The MBS FileMaker/Xojo plugin ships with its own built-in engine historically (older Tesseract 3.x). To use modern Tesseract 4.x or later you must explicitly load the newer native libraries using MBS("OCR.Load"; Path). Use MBS("OCR.IsLoaded") to check whether a newer engine is active. This avoids accidentally using mismatched data files and improves accuracy and speed on modern versions.

Warning: Using tessdata files for a different major Tesseract version than the library can crash the process. Always match the library version and tessdata set.

Where to get the libraries (official & common sources)

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
brew install tesseract
brew install tesseract-lang   # optional: many extra languages

sudo apt-get update
sudo apt-get install libtesseract5 tesseract-ocr tesseract-ocr-

Loading Tesseract into the MBS plugin — practical examples

The MBS plugin provides three functions you’ll use:

• MBS("OCR.IsLoaded") — returns 1 if a newer Tesseract (4.x+) is loaded.
• MBS("OCR.Load"; Path) — load native library by full native path or filename (depending on OS and working dir).
• MBS("OCR.Initialize"; PathToTessdata; "eng") — point tesseract to the tessdata folder and select language(s).

Linux example

# (install libs once)
sudo apt-get install libtesseract5 tesseract-ocr-eng

# In FileMaker script (pseudo)
# load leptonica first if not part of the same library file:
MBS("OCR.Load"; "liblept.so.5") &
MBS("OCR.Load"; "libtesseract.so.5")

# then initialize (point to directory which contains tessdata):
MBS("OCR.Initialize"; "/usr/share/tesseract-ocr/4.00/tessdata"; "eng")

macOS example (Homebrew)

# install via Homebrew (once)
brew install tesseract
brew install tesseract-lang   # optional

# In FileMaker script:
MBS("OCR.Load"; "/opt/homebrew/lib/liblept.5.dylib") &
MBS("OCR.Load"; "/opt/homebrew/lib/libtesseract.4.dylib")

# initialize (point to tessdata root - common homebrew path is /opt/homebrew/Cellar/tesseract//share/tessdata)
MBS("OCR.Initialize"; "/opt/homebrew/share/tessdata"; "eng")

Windows example (UB-Mannheim installer)

# After installing to C:\Program Files\Tesseract-OCR
MBS("Process.SetCurrentDirectory"; "C:\\Program Files\\Tesseract-OCR") &
MBS("OCR.Load"; "libleptonica-6.dll") & 
MBS("OCR.Load"; "libtesseract-5.dll")

# Initialize: pass native path to parent of tessdata (must end with tessdata folder name)
MBS("OCR.Initialize"; "C:\\Program Files\\Tesseract-OCR\\tessdata"; "eng+deu")

Notes:

• If the leptonica code is included in the same dynamic library file you may only need to load one file. If not, load leptonica first then tesseract (order matters).
• On macOS the full path to the `.dylib` is usually required; on Linux a soname like libtesseract.so.5 can work if the loader searches the standard system library paths.
• On Windows you may need to set the current directory or ensure the DLLs are discoverable by the process loader (PATH or same folder).

Initializing OCR and language data (tessdata)

After the native library is loaded, call MBS("OCR.Initialize"; PathToTessdata; Lang). The PathToTessdata parameter must be a native path that ends with the folder name tessdata. The language string is usually an ISO 639-3 code (for English use "eng"). For multiple languages use plus sign: "eng+deu".

Important: data files are version-specific. Tesseract 4.x and 5.x use different tessdata models (tessdata_fast / tessdata_best); feeding 3.x data to a 4.x+ library or vice versa may crash the process.

MBS also provides a download for language files and an archive of ready-to-use tessdata that matches the plugin’s expectations — this can simplify deployment, especially on FileMaker Server where permissions and file access can be restricted.

Common troubleshooting tips

1. Check OCR.IsLoaded before relying on default bindings: If [ MBS("OCR.IsLoaded") = 0 ].
2. Library load errors: If MBS("OCR.Load") reports errors, confirm the path, file name and loader search paths. On macOS Homebrew paths differ by CPU architecture (/opt/homebrew vs /usr/local).
3. Missing tessdata files: If initialization fails or Tesseract aborts, check that tessdata contains the language model and any required auxiliary files. Some languages require additional traineddata or config files.
4. Version mismatch: If OCR crashes unexpectedly, confirm that the tessdata files were built for the same major engine version you loaded.
5. Server environments: On FileMaker Server, each server thread may need per-thread initialization: check MBS("OCR.IsInitialized") and initialize as needed for each execution thread.

Deployment checklist

• Ensure the correct native libraries (leptonica + libtesseract) are available on the target system.
• Ship or point to the matching tessdata folder; verify language files exist.
• Use MBS("OCR.Load") to load the native libraries when you require a newer engine (4.x or later).
• Initialize per-thread on server installations using MBS("OCR.Initialize").
• Test OCR on representative documents for each language to surface missing model files early.
• If Windows can't find a module, you may use Process.SetDllDirectory function to tell Windows where to find the DLL files.