Planning

Tesseract release planning

Here we can plan the next releases of Tesseract.

4.0.0

That will be the next release.

See also the discussion for issue #1423.

Open issues which should be fixed

• Issues with the "bug" label (see list here)

• Segmentation fault when training from .lstm extracted from tessdata/eng.traineddata Issue 1573

• Report a warning when the Tesseract initialisation code detects an unsupported locale setting. (See comment)

• Segfault on using -psm 0 when using fast eng.traineddata Issue 1167

• combine_lang_model does not print correct usage help Issue 1375

• Insufficient error message when output file cannot be created Issue 1424

• “no best words!!” on mixed language (fra+ara) items (see issue 235)

• Tesseract creates output for missing input (see issue 1023)

• mgr_.Init(traineddata_path.c_str()):Error:Assert failed: #1075 (see issue 1075)

• Some images translated to text using Tesseract 4 throw an error ... (see issue 1205)

Features wanted for this release

• Remove deprecated code

  This does not include OpenCL or the old Tesseract engine. Some recent commits already removed such code, for example API include files, so it could be good enough for 4.0.0.

• Script for installing only selected languages from github (see issue)

To be discussed

Depending on available resources and opinions, these suggestions will either be added to the planning for the next or a future release or abandoned.

• Enhance --list-langs to show additional information for scripts and languages like legacy / LSTM, version
  

  This will make the command slower, because each file must be opened and parsed. Add this as --list-langs-details or as --list-lang-details for one language file based on lang-code?

• --list-langs should also display the directory it is using

• Fix the autotools build so that the debug mode uses -O0 as intended

• Add option to optionally select implementation for dot product (CPU, SSE, AVX, ...)

• Relative includes for traineddata

  tessedit_load_sublangs should search for the sublangs relative to the parent, not starting in tessdata dir.

• More fixes for compiler warnings and issues reported by Coverity Scan

• Add a simple bash script for building tesseract

• New traineddata format

  In addition to the current proprietary format Tesseract could also support ZIP archives (see discussion). A possible implementation using libarchive is available, but needs more testing.

• "Training light" - Learning by doing (see issue)

• Modify text2image to use PrepareDistortedPix() #1052

• Fix #736 - text2image segfault on macOS

• Schedule date

Regression of features from 3.0x

Tesseract 4.0 should be a full replacement for Tesseract 3.05 and have the same features when used with the old OCR engine (--oem 0). The following regressions still need verification (are they really regressions, or are they just missing features for LSTM):

• User Words (See comment)

• User Patterns (See issue)

Features from 3.0x which are missing for LSTM

These features still work with the old OCR engine (--oem 0), but are missing and desired for LSTM.

• Black list / White list (See issue). Here is a workaround.

• hOCR font info (See comment)

Future release

Here we collect important issues and features for the release(s) following 4.0.0.

• New LSTM-based OSD detector (see comment).

• Remove Legacy Tesseract Engine (see issue)

• Better Multi-language implementation for training (See comment)

• ARM SIMD support for dot product #519

• Using OpenMP for dot product #983

• Issue 1353: Patch for /training/tessopt.cpp (see pull request 13)

  It looks like it is not possible to run more than one training in the same process. The pull request describes a possible fix, but does not include a complete implementation (low priority).