Segfault on using -psm 0 when using fast eng.traineddata

[jbarlow83]

Environment

• Tesseract Version: 4.00 alpha
• Commit Number: 1b0379c
• Platform: Presumably all - found on Ubuntu 17.04, confirmed on macOS Sierra

Current Behavior:

When using eng.traineddata from tessdata_fast in -psm 0 mode Tesseract crashes for all input files. Example:

b095cb28b6c868b99d19e1c64b48a626bc4cb944  osd.traineddata
31abd495e0f719db4f524c447e9d855124a0b0d6  eng.traineddata

$ tesseract -psm 0 testing/phototest.tif stdout
Segmentation fault

Behaviour is the same using tessdata_best.

After replacing with tessdata/eng.traineddata, OSD works fine:

b095cb28b6c868b99d19e1c64b48a626bc4cb944  osd.traineddata
cdcfae0c5c272b5b2f0406cc91ac5d022f7df7f4 eng.traineddata

$ tesseract -psm 0 testing/phototest.tif stdout
Page 1
Page number: 0
Orientation in degrees: 0
Rotate: 0
Orientation confidence: 15.98
Script: Latin
Script confidence: 460.00

I discovered this in the Ubuntu 17.04 PPA (ppa:alex-p/tesseract-ocr) and replicated it on macOS tesseract built from source.

Stack trace

Stack trace (Linux version)

#0  0x00007f5e14a5494d in tesseract::Classify::CharNormClassifier(TBLOB*, tesseract::TrainingSample const&, ADAPT_RESULTS*) () from /usr/lib/libtesseract.so.4
#1  0x00007f5e14a55885 in tesseract::Classify::DoAdaptiveMatch(TBLOB*, ADAPT_RESULTS*) () from /usr/lib/libtesseract.so.4
#2  0x00007f5e14a55f89 in tesseract::Classify::AdaptiveClassifier(TBLOB*, BLOB_CHOICE_LIST*) () from /usr/lib/libtesseract.so.4
#3  0x00007f5e14973c82 in os_detect_blob(BLOBNBOX*, OrientationDetector*, ScriptDetector*, OSResults*, tesseract::Tesseract*) ()
   from /usr/lib/libtesseract.so.4
#4  0x00007f5e1497413b in os_detect_blobs(GenericVector<int> const*, BLOBNBOX_CLIST*, OSResults*, tesseract::Tesseract*) () from /usr/lib/libtesseract.so.4
#5  0x00007f5e1497453d in os_detect(TO_BLOCK_LIST*, OSResults*, tesseract::Tesseract*) () from /usr/lib/libtesseract.so.4
#6  0x00007f5e14974782 in orientation_and_script_detection(STRING&, OSResults*, tesseract::Tesseract*) () from /usr/lib/libtesseract.so.4
#7  0x00007f5e14943f8f in tesseract::TessBaseAPI::DetectOS(OSResults*) ()
   from /usr/lib/libtesseract.so.4
#8  0x00007f5e149440b9 in tesseract::TessBaseAPI::DetectOrientationScript(int*, float*, char const**, float*) () from /usr/lib/libtesseract.so.4
#9  0x00007f5e149441b1 in tesseract::TessBaseAPI::GetOsdText(int) ()
   from /usr/lib/libtesseract.so.4
#10 0x00007f5e1494bcd4 in tesseract::TessOsdRenderer::AddImageHandler(tesseract::TessBaseAPI*) () from /usr/lib/libtesseract.so.4

[amitdo]

tesseract -psm 0 testing/phototest.tif stdout

The eng is the default lang even when you use --psm 0.

The OSD module is based on the legacy engine. 'fast' and 'best' traineddatas were trained for LSTM only.

[amitdo]

Try this:

tesseract --psm 0 -l osd testing/phototest.tif stdout

[jbarlow83]

The explicit -l osd works around the issue.

Although it shouldn't crash even if the arguments are invalid.

[brlin-tw]

Here's a more complete stack trace from issue #1258 with commit 000d027 with debugging enabled:

#0  tesseract::Classify::CharNormClassifier (this=0x7ffff7fd1010, blob=0x5d3f080, sample=..., 
    adapt_results=0x5cc7630) at adaptmatch.cpp:1349
#1  0x00007ffff77052a8 in tesseract::Classify::DoAdaptiveMatch (this=0x7ffff7fd1010, Blob=0x5d3f080, 
    Results=0x5cc7630) at adaptmatch.cpp:1581
#2  0x00007ffff76fff89 in tesseract::Classify::AdaptiveClassifier (this=0x7ffff7fd1010, Blob=0x5d3f080, 
    Choices=0x7fffffffc0d0) at adaptmatch.cpp:192
#3  0x00007ffff75feb32 in os_detect_blob (bbox=0x5cd6870, o=0x7fffffffc170, s=0x7fffffffc180, 
    osr=0x7fffffffcc50, tess=0x7ffff7fd1010) at osdetect.cpp:354
#4  0x00007ffff75fe756 in os_detect_blobs (allowed_scripts=0x0, blob_list=0x7fffffffca00, 
    osr=0x7fffffffcc50, tess=0x7ffff7fd1010) at osdetect.cpp:305
#5  0x00007ffff75fe490 in os_detect (port_blocks=0x7fffffffcb90, osr=0x7fffffffcc50, tess=0x7ffff7fd1010)
    at osdetect.cpp:264
#6  0x00007ffff75fe0b1 in orientation_and_script_detection (filename=..., osr=0x7fffffffcc50, 
    tess=0x7ffff7fd1010) at osdetect.cpp:225
#7  0x00007ffff75c047e in tesseract::TessBaseAPI::DetectOS (this=0x607360 <main::api>, osr=0x7fffffffcc50)
    at baseapi.cpp:2382
#8  0x00007ffff75be7db in tesseract::TessBaseAPI::DetectOrientationScript (this=0x607360 <main::api>, 
    orient_deg=0x7fffffffd420, orient_conf=0x7fffffffd424, script_name=0x7fffffffd438, 
    script_conf=0x7fffffffd428) at baseapi.cpp:1896
#9  0x00007ffff75be8fd in tesseract::TessBaseAPI::GetOsdText (this=0x607360 <main::api>, page_number=0)
    at baseapi.cpp:1928
#10 0x00007ffff75cb8bc in tesseract::TessOsdRenderer::AddImageHandler (this=0x81c890, 
    api=0x607360 <main::api>) at renderer.cpp:268
#11 0x00007ffff75cafe5 in tesseract::TessResultRenderer::AddImage (this=0x81c890, api=0x607360 <main::api>)
    at renderer.cpp:86
#12 0x00007ffff75bbd11 in tesseract::TessBaseAPI::ProcessPage (this=0x607360 <main::api>, pix=0x40d8140, 
    page_index=0, filename=0x7fffffffde53 "/tmp/com.github.ocrmypdf.ec7wbvyw/000001.ocr.png", 
    retry_config=0x0, timeout_millisec=0, renderer=0x81c890) at baseapi.cpp:1224
#13 0x00007ffff75bb973 in tesseract::TessBaseAPI::ProcessPagesInternal (this=0x607360 <main::api>, 
    filename=0x7fffffffde53 "/tmp/com.github.ocrmypdf.ec7wbvyw/000001.ocr.png", retry_config=0x0, 
    timeout_millisec=0, renderer=0x81c890) at baseapi.cpp:1156
#14 0x00007ffff75bb385 in tesseract::TessBaseAPI::ProcessPages (this=0x607360 <main::api>, 
    filename=0x7fffffffde53 "/tmp/com.github.ocrmypdf.ec7wbvyw/000001.ocr.png", retry_config=0x0, 
    timeout_millisec=0, renderer=0x81c890) at baseapi.cpp:1056
#15 0x0000000000403ae6 in main (argc=11, argv=0x7fffffffda28) at tesseractmain.cpp:529

[Shreeshrii]

@stweil Should the program use -l osd by default internally for 4.0.0 when --psm 0 is used?

[amitdo]

Should the program use -l osd by default internally for 4.0.0 when --psm 0 is used?

Yes, IMO.