Get correct image orientation by Google Cloud Vision api (TEXT_DETECTION)

As described in the Public Issue Tracker, our engineering team is now aware of this feature request, and there is currently no ETA for its implementation.

Note, orientation information may already be available in your image's metadata. An example of how to extract the metadata can be seen in this Third-party library.

A broad workaround would be to check the returned "boundingPoly" "vertices" for the returned "textAnnotations". By calculating the width and height of each detected word's rectangle, you can figure out if an image is not right-side-up if the rectangle 'height' > 'width' (aka the image is sideways).

You can leverage the fact that we know the sequence of characters in a word to infer the orientation of a word as follows (obviously slightly different logic for non-LTR languages):

for page in annotation:
    for block in page.blocks:
        for paragraph in block.paragraphs:
            for word in paragraph.words:
                if len(word.symbols) < MIN_WORD_LENGTH_FOR_ROTATION_INFERENCE:
                    continue
                first_char = word.symbols[0]
                last_char = word.symbols[-1]
                first_char_center = (np.mean([v.x for v in first_char.bounding_box.vertices]),np.mean([v.y for v in first_char.bounding_box.vertices]))
                last_char_center = (np.mean([v.x for v in last_char.bounding_box.vertices]),np.mean([v.y for v in last_char.bounding_box.vertices]))

                #upright or upside down
                if np.abs(first_char_center[1] - last_char_center[1]) < np.abs(top_right.y - bottom_right.y): 
                    if first_char_center[0] <= last_char_center[0]: #upright
                        print 0
                    else: #updside down
                        print 180
                else: #sideways
                    if first_char_center[1] <= last_char_center[1]:
                        print 90
                    else:
                        print 270

Then you can use the orientation of individual words to infer the orientation of the document overall.