def result(self, path):
'''Returns all the results from calling the service on the 'path'. The
results are returned as an TRResult named tuple.
'''
# Check if we already processed it.
if path in self._results:
if __debug__: log('returning already-known result for {}', path)
return self._results[path]
# Read the image and proceed with contacting the service.
(image, error) = self._image_from_file(path)
if error:
return error
base_url = 'https://westus.api.cognitive.microsoft.com/vision/v2.0/'
url = base_url + 'recognizeText'
params = {'mode': 'Handwritten'}
headers = {'Ocp-Apim-Subscription-Key': self._credentials,
'Content-Type': 'application/octet-stream'}
# The Microsoft API for extracting text requires two phases: one call
# to submit the image for processing, then polling to wait until the
# text is ready to be retrieved.
if __debug__: log('sending file to MS cloud service')
response, error = net('post', url, headers = headers, params = params, data = image)
if isinstance(error, NetworkFailure):
if __debug__: log('network exception: {}', str(error))
return TRResult(path = path, data = {}, text = '', error = str(error))
elif isinstance(error, RateLimitExceeded):
# https://docs.microsoft.com/en-us/azure/azure-resource-manager/resource-manager-request-limits
# The headers should have a Retry-After number in seconds.
sleep_time = 30
if 'Retry-After' in response.headers:
sleep_time = int(response.headers['Retry-After'])
if __debug__: log('sleeping for {} s and retrying', sleep_time)
sleep(sleep_time)
return self.result(path) # Recursive invocation
elif error:
raise error
if 'Operation-Location' in response.headers:
polling_url = response.headers['Operation-Location']
else:
if __debug__: log('no operation-location in response headers')
raise ServiceFailure('Unexpected response from Microsoft server')
if __debug__: log('polling MS for results ...')
analysis = {}
poll = True
while poll:
# I never have seen results returned in 1 second, and meanwhile
# the repeated polling counts against your rate limit. So, wait
# for 2 s to reduce the number of calls.
sleep(2)
response, error = net('get', polling_url, polling = True, headers = headers)
if isinstance(error, NetworkFailure):
if __debug__: log('network exception: {}', str(error))
return TRResult(path = path, data = {}, text = '', error = str(error))
elif isinstance(error, RateLimitExceeded):
# Pause to let the server reset its timers. It seems that MS
# doesn't send back a Retry-After header when rated limited
# during polling, but I'm going to check it anyway, in case.
sleep_time = 30
if 'Retry-After' in response.headers:
sleep_time = int(response.headers['Retry-After'])
if __debug__: log('sleeping for {} s and retrying', sleep_time)
sleep(sleep_time)
elif error:
raise error
# Sometimes the response comes back without content. I don't know
# if that's a bug in the Azure system or not. It's not clear what
# else should be done except keep going.
if response.text:
analysis = response.json()
if 'recognitionResult' in analysis:
poll = False
if 'status' in analysis and analysis['status'] == 'Failed':
poll = False
else:
if __debug__: log('received empty result from Microsoft.')
if __debug__: log('results received.')
# Have to extract the text into a single string.
full_text = ''
if 'recognitionResult' in analysis:
lines = analysis['recognitionResult']['lines']
sorted_lines = sorted(lines, key = lambda x: (x['boundingBox'][1], x['boundingBox'][0]))
full_text = '\n'.join(x['text'] for x in sorted_lines)
# Create our particular box structure for annotations. The Microsoft
# structure is like this: data['recognitionResult']['lines'] contains
# a list of dict with keys 'words', 'boundingBox', and 'text'.
boxes = []
for chunk in lines:
boxes.append(TextBox(boundingBox = chunk['boundingBox'], text = chunk['text']))
# Put it all together.
self._results[path] = TRResult(path = path, data = analysis,
text = full_text, boxes = boxes,
error = None)
return self._results[path]
def result(self, path):
'''Returns the results from calling the service on the 'path'. The
results are returned as an TRResult named tuple.
'''
# Read the image and proceed with contacting the service.
(image, error) = self._image_from_file(path)
if error:
return error
try:
if __debug__: log('building Google vision API object')
client = gv.ImageAnnotatorClient()
image = gv.types.Image(content=image)
context = gv.types.ImageContext(
language_hints=['en-t-i0-handwrit'])
# Iterate over the known API calls and store each result.
result = dict.fromkeys(self._known_features)
for feature in self._known_features:
if __debug__:
log('sending image to Google for {} ...', feature)
response = getattr(client, feature)(image=image,
image_context=context)
if __debug__: log('received result.')
result[feature] = MessageToDict(response)
# Extract text and bounding boxes into our format.
# Their structure looks like this:
#
# result['document_text_detection']['fullTextAnnotation']['pages'][0]['blocks'][0].keys()
# --> dict_keys(['boundingBox', 'confidence', 'paragraphs', 'blockType'])
#
# result['document_text_detection']['fullTextAnnotation']['pages'][0]['blocks'][0]['paragraphs'][0].keys()
# --> dict_keys(['boundingBox', 'words', 'confidence'])
#
# https://cloud.google.com/vision/docs/reference/rest/v1/images/annotate#Block
full_text = ''
boxes = []
if 'fullTextAnnotation' in result['document_text_detection']:
fta = result['document_text_detection']['fullTextAnnotation']
full_text = fta['text']
for block in fta['pages'][0]['blocks']:
for para in block['paragraphs']:
for word in para['words']:
text = ''
for symbol in word['symbols']:
text += symbol['text']
bb = word['boundingBox']['vertices']
corners = corner_list(bb)
if corners:
boxes.append(
TextBox(boundingBox=corners, text=text))
else:
# Something is wrong with the vertex list.
# Skip it and continue.
if __debug__:
log('bad bb for {}: {}', text, bb)
return TRResult(path=path,
data=result,
boxes=boxes,
text=full_text,
error=None)
except google.api_core.exceptions.PermissionDenied as ex:
text = 'Authentication failure for Google service -- {}'.format(ex)
raise AuthFailure(text)
except KeyboardInterrupt as ex:
raise
except Exception as ex:
if isinstance(ex, KeyError):
# Can happen if you control-C in the middle of the Google call.
# Result is "Exception ignored in: 'grpc._cython.cygrpc._next'"
# printed to the terminal and we end up here.
raise KeyboardInterrupt
else:
text = 'Error: {} -- {}'.format(str(ex), path)
return TRResult(path=path,
data={},
boxes=[],
text='',
error=text)
def amazon_result(self, file_path, variant, api_method, image_keyword,
response_key, value_key, block_key):
'''Returns the results from calling the service on the 'file_path'.
The results are returned as an TRResult named tuple.
'''
# Check if we already processed it.
if file_path in self._results:
if __debug__:
log('returning already-known result for {}', file_path)
return self._results[file_path]
# Read the image and proceed with contacting the service.
# If any exceptions occur, let them be passed to caller.
(image, error) = self._image_from_file(file_path)
if error:
return TRResult(path=file_path,
data={},
boxes=[],
text='',
error=error)
if __debug__: log('setting up Amazon client function "{}"', variant)
creds = self._credentials
try:
client = boto3.client(
variant,
region_name=creds['region_name'],
aws_access_key_id=creds['aws_access_key_id'],
aws_secret_access_key=creds['aws_secret_access_key'])
if __debug__: log('calling Amazon API function')
response = getattr(client, api_method)(**{
image_keyword: {
'Bytes': image
}
})
if __debug__:
log('received {} blocks', len(response[response_key]))
full_text = ''
boxes = []
width, height = imagesize.get(file_path)
for block in response[response_key]:
if value_key in block and block[value_key] == "WORD":
text = block[block_key]
full_text += (text + ' ')
corners = corner_list(block['Geometry']['Polygon'], width,
height)
if corners:
boxes.append(TextBox(boundingBox=corners, text=text))
else:
# Something's wrong with the vertex list. Skip & continue.
if __debug__: log('bad bb for {}: {}', text, bb)
result = TRResult(path=file_path,
data=response,
boxes=boxes,
text=full_text,
error=None)
self._results[file_path] = result
return result
except KeyboardInterrupt as ex:
raise
except Exception as ex:
text = 'Error: {} -- {}'.format(str(ex), file_path)
return TRResult(path=file_path,
data={},
boxes=[],
text='',
error=text)