Annotating image file to text using googleapiclient

Question

I am trying to annotate a local image file using google cloud services. I followed the instructions given here https://cloud.google.com/natural-language/docs/reference/libraries, and setup the google API. The given test examples on the page executed without any problem. However, when I am trying to actually annotate a file I am getting error, here is the code I am using:

files = [];
files.append("/opt/lampp/htdocs/test.jpg");

def get_text_from_files(fileNames):
    texts = detect_text(fileNames);

def detect_text(fileNames):
    max_results = 6;
    num_retries=3;
    service = googleapiclient.discovery.build('language', 'v1');
    batch_request = [];
    for filename in fileNames:
        request = {
            'image': {},
            'features': [{
                'type': 'TEXT_DETECTION',
                'maxResults': max_results,
            }]
        }

        with open(filename, 'rb') as image_file:
            request['image']['content'] = base64.b64encode(image_file.read()).decode('UTF-8');
        batch_request.append(request);

    request = service.images().annotate(body={'requests': batch_request});

    try:
        responses = request.execute(num_retries=num_retries)
        if 'responses' not in responses:
            return {};

        text_response = {};
        for filename, response in zip(
                input_filenames, responses['responses']):

            if 'error' in response:
                logging.error('API Error for {}: {}'.format(
                    filename,
                    response['error'].get('message', '')))
                continue

            text_response[filename] = response.get('textAnnotations', [])

        return text_response;

    except googleapiclient.errors.HttpError as e:
        print ('Http Error for {}: {}', e)
    except KeyError as e2:
        print ('Key error: {}', e2)


get_text_from_files(files);

But I am getting error, I have given the stack trace below:

Traceback (most recent call last):
  File "test.py", line 68, in <module>
    get_text_from_files(pdf);
  File "test.py", line 21, in get_text_from_files
    texts = detect_text(fileNames);
  File "test.py", line 41, in detect_text
    request = service.images().annotate(body={'requests': batch_request});
AttributeError: 'Resource' object has no attribute 'images'

Thanks in advance.

Answer 1

Note that you are using the wrong Google API Client Python Library. You are using the Natural Language API, while the one that you want to use is the Vision API. The error message AttributeError: 'Resource' object has no attribute 'images' indicates that the resource associated to the Language API does not have any images attribute. In order to solve this issue, it should be enough to do the following change:

# Wrong API being used
service = googleapiclient.discovery.build('language', 'v1');
# Correct API being used
service = googleapiclient.discovery.build('vision', 'v1');

In this Google API Client Libraries page you will find the whole list of available APIs and their names and versions available. And here, there's the complete documentation for the Vision API legacy API Client Library.

Finally, let me recommend you the usage of the idiomatic Client Libraries instead of the legacy API Client Libraries. They are much more intuitive to use and there are some good documentation references in their GitHub page.