crash on rotated image about tesserocr HOT 13 CLOSED

AnalyseLayout returns:

Page iterator or None on error or an empty page.

So you need to check if the returned value is not None before calling Orientation.

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Right, it is None. But rotating an image 3 deg shouldn't cause that to happen correct?

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Also, just tested via the c-api and it works fine. So not an issue with tesseract or leptonica.

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If you look at the source code linked in my previous comment, all it does is call the respective AnalyseLayout C function and if its value is NULL returns None. Is it possible that you're getting None due to the issue in #4?

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See #5 (comment)

Here's part of the working code if it helps

def get_native_orientation(tesseract, leptonica, api, path, mode=PAGE_MODE):
    tesseract.TessBaseAPISetPageSegMode(api, mode)
    pix = leptonica.pixRead(path)
    tesseract.TessBaseAPISetImage2(api, pix)

    if tesseract.TessBaseAPIRecognize(api, None):
        leptonica.pixDestroy(byref(pix))
        tesseract.TessBaseAPIDelete(api)
        raise Exception('Tesseract recognition failed')

    it = tesseract.TessBaseAPIAnalyseLayout(api)
    orientation, direction, line_order = c_int(), c_int(), c_int()
    skew = c_float()

    tesseract.TessPageIteratorOrientation(
        it, byref(orientation), byref(direction), byref(line_order),
        byref(skew))

    return orientation.value, direction.value, line_order.value, skew.value

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Alright, the problem seems to be with the usage of PIL.Image. If you use the SetImageFile method instead of SetImage it'll work. I'm going to debug this issue and apply the appropriate fix.

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Hey could you please test with the latest commit? It should now work as expected with PIL images.

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it works, thanks! Can you let me know once you publish the new version?

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Another issue tho. It works for 3deg and 4deg, but crashes when the image is rotated 5deg. And fwiw, the c-api crashes as well with Segmentation fault: 11.

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With the 5 degrees tilt, tesseract fails to detect any text in the image (try tesseract eurotext_ang.tiff -) so this isn't related to the issue we fixed here.

Note that the tesseract executable applies a different logic to output the orientation when -psm 0 is specified. In our case we're using psm 1 and given that no text is detected, AnalyseLayout returns None.

Unfortunately, I didn't expose the DetectOS which is used in tesseract 3.04.00 to write the same logic in tesserocr. The nice thing is they made it much easier to do in tesseract 3.04.01 but implementing it will break compatibility with version 3.04.00 so I'm gonna see how to do it properly while maintaining backward compatibility (preferably with 3.02 as well).

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So does that explain why running the script with psm=0 returns null
results? I wasnt aware of 'DetectOS' but it looks like it may be what i
need.

CR #6

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Yes certainly does, seems that AnalyseLayout always returns None when psm is 0. Orientation needs to be detected differently when psm is 0, I'm going to work on it with support for 3.04.00 and the newer 3.04.01 as well, will let you know once it's ready.

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Hello, Anyone can help with my conversion of C/C++ tesseract-ocr code to Python?
https://stackoverflow.com/questions/60166781/ctypesconvert-the-c-c-tesseract-ocr-code-to-python

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