Google cloud vision not accepting base64 encoded images python

Question

I'm having a problem with base64 encoded images sent to Google Cloud Vision. Funny thing is that if I send the image via URI, it works fine, so I suspect there is something wrong the way I'm encoding.

Here's the deal:

from google.cloud import vision
import base64
client = vision.ImageAnnotatorClient()
image_path ='8720911950_91828a2aeb_b.jpg'
with open(image_path, 'rb') as image:
    image_content = image.read()
    content = base64.b64encode(image_content)   
    response = client.annotate_image({'image': {'content': content}, 'features': [{'type': vision.enums.Feature.Type.LABEL_DETECTION}],})
    print(response)

The response I get always is:

error {
  code: 3
  message: "Bad image data."
}

If I try using URI instead:

response = client.annotate_image({'image': {'source': {'image_uri': 'https://farm8.staticflickr.com/7408/8720911950_91828a2aeb_b.jpg'}}, 'features': [{'type': vision.enums.Feature.Type.LABEL_DETECTION}],})

Response is ok...

label_annotations {
  mid: "/m/0168g6"
  description: "factory"
  score: 0.7942917943000793
}
label_annotations {
  mid: "/m/03rnh"
  description: "industry"
  score: 0.7761002779006958
}

I've followed the recommended way to encode from Google

Any idea what is wrong here?

@Leon I get this "TypeError: '/9j/4AAQSkZJRgABAQEA8ADwAAD/4gJASUNDX1BST0ZJTEUAAQEAAAIwQURCRQIQAABtbnRyUkdCIFhZWiAHzwAGAAMAAAAAAAB has type str, but expected one of: bytes " — AlejandroVK
Have you tried the other way of doing it as in this example, where encoding is obviously done automatically inside the types.Image() constructor. — Leon
@Leon I don't want to use what they call shortcuts, I want to use the annotator client so I select what type of analysis, and more important, send more than one image per request — AlejandroVK

Leon Leon · Accepted Answer · 2017-08-15T15:54:57

I don't have any experience with Google Cloud Vision, however after looking at their documentation and examples, my feeling is that the linked documentation page about base64 encoding of image data is for the case when you create and send the HTTP requests on your own, without using vision.ImageAnnotatorClient. The latter seems to encode the image data automatically, hence in your example double encoding is applied. Therefore I believe that you should remove the encoding step from your code:

from google.cloud import vision
import base64
client = vision.ImageAnnotatorClient()
image_path ='8720911950_91828a2aeb_b.jpg'
with open(image_path, 'rb') as image:
    content = image.read()
    response = client.annotate_image({'image': {'content': content}, 'features': [{'type': vision.enums.Feature.Type.LABEL_DETECTION}],})
    print(response)

Google cloud vision not accepting base64 encoded images python

2 Answers