I'm still hoping to learn how to use GetComponentImages / SetRectangle
better, but I found a workaround to get what I need out of GetIterator /
iterate_level... BoundingBoxInternal is not something I can find
documentation for, but I saw a reference to it
<https://zdenop.github.io/tesseract-doc/group___advanced_a_p_i.html#ga56369b1654400ef97e581bb65749ec3d>
and
decided to see if I could get it to work. I now see bounding boxes for my
faster and more correct method.
#!/usr/bin/python
from PIL import Image
Image.MAX_IMAGE_PIXELS=1000000000
from tesserocr import PyTessBaseAPI, RIL, iterate_level
image = Image.open('/Users/gordot2/tess-install/tesseract/scan_2_new.tif')
with PyTessBaseAPI() as api:
api.SetImage(image)
api.Recognize()
api.SetVariable("save_blob_choices","T")
ri=api.GetIterator()
level=RIL.WORD
for r in iterate_level(ri, level):
print r.BoundingBoxInternal(level)
symbol = r.GetUTF8Text(level)
conf = r.Confidence(level)
if symbol:
print u'symbol {},conf:
{}\n'.format(symbol,conf).encode('utf-8')
On Monday, January 2, 2017 at 7:25:39 AM UTC-5, T G wrote:
>
> I've continued to spend a little time each day working on my problem. I've
> found something that fuels my desire to understand what GetComponentImages
> does differently from iterate_level.
>
> from PIL import Image
>
> Image.MAX_IMAGE_PIXELS=1000000000
>
> from tesserocr import PyTessBaseAPI, RIL
>
>
> image =
> Image.open('/Users/chrysrobyn/tess-install/tesseract/scan_2_new.tif')
>
> with PyTessBaseAPI() as api:
>
> api.SetImage(image)
>
> api.Recognize()
>
> api.SetVariable("save_blob_choices","T")
>
> boxes = api.GetComponentImages(RIL.WORD, True)
>
> print 'Found {} textword image components.'.format(len(boxes))
>
> print enumerate(boxes)
>
> for i, (im, box, _, _) in enumerate(boxes):
>
> # api.SetRectangle(box['x'], box['y'], box['w'], box['h'])
>
> api.SetRectangle(int(box['x'])-8, int(box['y'])-8,
> int(box['w'])+16, int(box['h'])+16)
>
> ocrResult = api.GetUTF8Text()
>
> conf = api.MeanTextConf()
>
> thresholdedImage = api.GetThresholdedImage()
>
>
> thresholdedImage.save('/Users/chrysrobyn/tess-install/tesseract/scan_2_new_piece'+str(i)+str(ocrResult)+'.tif')
>
> if ocrResult:
>
> print u'symbol {},conf:
> {}\n'.format(ocrResult,conf).encode('utf-8')
>
> I've highlighted in green my debugging steps. 1) I started saving the
> boxed images to see what commonality I could see. It's picking out words
> that work in my Example2.py script below. Unfortunately, api.GetUTF8Text()
> isn't returning anything for the vast majority of these boxes (second
> example below, plus this modified one). r.GetUTF8Text() (first example
> below), however, picks it up with high confidence. 2) I started playing
> with making bigger boxes. This has yielded some improvements, but nothing
> drastic.
>
> I'm again left struggling to understand: What can I do to
> GetComponentImages / SetRectangle / GetUTF8Text to make it match
> GetIterator / iterate_level / GetUTF8Text?
>
> On Friday, December 30, 2016 at 6:21:49 AM UTC-5, T G wrote:
>>
>> I'm trying to learn Python in parallel with the Tesseract API. My end
>> goal is to learn how to use the Tesseract API to be able to read a document
>> and do some basic error checking. I've found a few examples that seem to be
>> good places to start, but I'm having trouble understanding the difference
>> between two pieces of code that, while different in behavior, seem to me
>> like they should be equivalent. These were both modified slightly from
>> https://pypi.python.org/pypi/tesserocr .
>>
>> The first example produces this output:
>>
>> $ time ./GetComponentImagesExample2.py|tail -2
>> symbol MISSISSIPPI,conf: 88.3686599731
>>
>>
>> real 0m14.227s
>> user 0m13.534s
>> sys 0m0.397s
>>
>> This is accurate and completes in 14 seconds. Reviewing the rest of the
>> output, it is pretty good -- I'm probably a few SetVariable commands away
>> from 99+% accuracy.
>>
>> $ ./GetComponentImagesExample2.py|wc -l
>> 1289
>>
>> Manually reviewing the results, it appears to get all the text.
>>
>> #!/usr/bin/pythonfrom PIL import ImageImage.MAX_IMAGE_PIXELS=1000000000from
>> tesserocr import PyTessBaseAPI, RIL, iterate_level
>>
>> image =
>> Image.open('/Users/chrysrobyn/tess-install/tesseract/scan_2_new.tif')with
>> PyTessBaseAPI() as api:
>> api.SetImage(image)
>> api.Recognize()
>> api.SetVariable("save_blob_choices","T")
>> ri=api.GetIterator()
>> level=RIL.WORD
>> boxes = api.GetComponentImages(RIL.WORD, True)
>> print 'Found {} textline image components.'.format(len(boxes))
>> for r in iterate_level(ri, level):
>> symbol = r.GetUTF8Text(level)
>> conf = r.Confidence(level)
>> if symbol:
>> print u'symbol {},conf: {}\n'.format(symbol,conf).encode('utf-8')
>>
>> The second example produces this output.
>>
>> $ time ./GetComponentImagesExample4.py|tail -4
>> symbol MISSISS IPPI,conf: 85
>>
>>
>> real 0m17.524s
>> user 0m16.600s
>> sys 0m0.427s
>>
>> This is less accurate (extra space detected in a word) and slower (takes
>> 17.5 seconds).
>>
>> $ ./GetComponentImagesExample4.py|wc -l
>> 223
>>
>> This is sorely lacking a large amount of text and I don't understand why
>> it misses some stuff.
>>
>> #!/usr/bin/pythonfrom PIL import ImageImage.MAX_IMAGE_PIXELS=1000000000from
>> tesserocr import PyTessBaseAPI, RIL
>>
>> image =
>> Image.open('/Users/chrysrobyn/tess-install/tesseract/scan_2_new.tif')with
>> PyTessBaseAPI() as api:
>> api.SetImage(image)
>> api.Recognize()
>> api.SetVariable("save_blob_choices","T")
>> boxes = api.GetComponentImages(RIL.WORD, True)
>> print 'Found {} textword image components.'.format(len(boxes))
>> for i, (im, box, _, _) in enumerate(boxes):
>> api.SetRectangle(box['x'], box['y'], box['w'], box['h'])
>> ocrResult = api.GetUTF8Text()
>> conf = api.MeanTextConf()
>> if ocrResult:
>> print u'symbol {},conf:
>> {}\n'.format(ocrResult,conf).encode('utf-8')# print (u"Box[{0}]:
>> x={x}, y={y}, w={w}, h={h}, "# "confidence: {1}, text:
>> {2}").format(i, conf, ocrResult, **box).encode('utf-8')
>>
>> My end goal relies on understanding where text is found in the document,
>> so I need the bounding boxes like the second example. As near as I can
>> tell, the iterate_level doesn't expose the coordinates of the found text,
>> so I need the GetComponentImages... but the output is not equivalent.
>>
>> Why do these pieces of code behave differently in accuracy? Can I get
>> GetComponentImages to match GetIterator?
>>
>>
>> Thanks for any help.
>>
>
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