Format OCR text annotation from Cloud Vision API in Python

Question

I am using the Google Cloud Vision API for Python on a small program I'm using. The function is working and I get the OCR results, but I need to format these before being able to work with them.

This is the function:

# Call to OCR API
def detect_text_uri(uri):
    """Detects text in the file located in Google Cloud Storage or on the Web.
    """
    client = vision.ImageAnnotatorClient()
    image = types.Image()
    image.source.image_uri = uri

    response = client.text_detection(image=image)
    texts = response.text_annotations

    for text in texts:
        textdescription = ("    "+ text.description )
        return textdescription

I specifically need to slice the text line by line and add four spaces in the beginning and a line break in the end, but at this moment this is only working for the first line, and the rest is returned as a single line blob.

I've been checking the official documentation but didn't really find out about the format of the response of the API.

Ciborium

Answer 1

You are almost right there. As you want to slice the text line by line, instead of looping the text annotations, try to get the direct 'description' from google vision's response as shown below.

def parse_image(image_path=None):
    """
    Parse the image using Google Cloud Vision API, Detects "document" features in an image
    :param image_path: path of the image
    :return: text content
    :rtype: str
    """

    client = vision.ImageAnnotatorClient()
    response = client.text_detection(image=open(image_path, 'rb'))
    text = response.text_annotations
    del response     # to clean-up the system memory

    return text[0].description

The above function returns a string with the content in the image, with the lines separated by "\n"

Now, you can add prefix & suffix as you need to each line.

image_content = parse_image(image_path="path\to\image")

my_formatted_text = ""
for line in image_content.split("\n"):
    my_formatted_text += "    " + line + "\n"

my_formatted_text is the text you need.

Cyanate