Python调整图像大小并发送到谷歌视觉功能

Question

由于谷歌视觉在输入图像大小上有一些restrictions，我想先调整输入图像的大小，然后使用detect_labels() 函数。

这是他们的sample code

def detect_labels(path):
"""Detects labels in the file."""
vision_client = vision.Client()

with io.open(path, 'rb') as image_file:
    content = image_file.read()

image = vision_client.image(content=content)

labels = image.detect_labels()
print('Labels:')

for label in labels:
    print(label.description)

他们使用io 打开图像文件。我想知道这样，如何在内存中调整图像大小，然后调用detect_labels()？

Answer 1

您可以通过 PIL/Pillow 调整图像大小，然后将其传递给客户端：

替换

with io.open(path, 'rb') as image_file:
    content = image_file.read()

与

# Warning: untested code, may require some fiddling
import Image, StringIO

img = Image.open(path)
img.thumbnail((512, 512))
buffer = StringIO.StringIO()
img.save(buffer, "PNG")

content = buffer.getvalue()

Answer 2

python3 的代码：

致谢：@kristaps

import io
from PIL import Image
img = Image.open(path)
img.thumbnail((512, 512))
buffer = io.BytesIO()
img.save(buffer, "JPEG")
content = buffer.getvalue()