IndexError:带有 Google Cloud Vision API 的字节数组
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【中文标题】IndexError:带有 Google Cloud Vision API 的字节数组【英文标题】:IndexError: bytearray with Google Cloud Vision API 【发布时间】:2021-02-22 00:56:27 【问题描述】:我正在尝试使用 Google Cloud Vision API 来检测图像中的文本。我按照以下教程中的代码进行操作:https://cloud.google.com/vision/docs/fulltext-annotations
完整代码如下:
import argparse
from enum import Enum
import io
from google.cloud import vision
from PIL import Image, ImageDraw
class FeatureType(Enum):
PAGE = 1
BLOCK = 2
PARA = 3
WORD = 4
SYMBOL = 5
def draw_boxes(image, bounds, color):
"""Draw a border around the image using the hints in the vector list."""
draw = ImageDraw.Draw(image)
for bound in bounds:
draw.polygon([
bound.vertices[0].x, bound.vertices[0].y,
bound.vertices[1].x, bound.vertices[1].y,
bound.vertices[2].x, bound.vertices[2].y,
bound.vertices[3].x, bound.vertices[3].y], None, color)
return image
def get_document_bounds(image_file, feature):
"""Returns document bounds given an image."""
client = vision.ImageAnnotatorClient()
bounds = []
with io.open(image_file, 'rb') as image_file:
content = image_file.read()
image = vision.Image(content=content)
response = client.document_text_detection(image=image)
document = response.full_text_annotation
# Collect specified feature bounds by enumerating all document features
for page in document.pages:
for block in page.blocks:
for paragraph in block.paragraphs:
for word in paragraph.words:
for symbol in word.symbols:
if (feature == FeatureType.SYMBOL):
bounds.append(symbol.bounding_box)
if (feature == FeatureType.WORD):
bounds.append(word.bounding_box)
if (feature == FeatureType.PARA):
bounds.append(paragraph.bounding_box)
if (feature == FeatureType.BLOCK):
bounds.append(block.bounding_box)
# The list `bounds` contains the coordinates of the bounding boxes.
return bounds
def render_doc_text(filein, fileout):
image = Image.open(filein)
bounds = get_document_bounds(filein, FeatureType.BLOCK)
draw_boxes(image, bounds, 'red')
bounds = get_document_bounds(filein, FeatureType.PARA)
draw_boxes(image, bounds, 'red')
bounds = get_document_bounds(filein, FeatureType.WORD)
draw_boxes(image, bounds, 'red')
if fileout != 0:
image.save(fileout)
else:
image.show()
if __name__ == '__main__':
parser = argparse.ArgumentParser()
parser.add_argument('detect_file', help='The image for text detection.')
parser.add_argument('-out_file', help='Optional output file', default=0)
args = parser.parse_args()
render_doc_text(args.detect_file, args.out_file)
我正在使用带有 Python 3.7 的 Windows 10,并在命令提示符中使用以下代码:
C:\Users\ariel\Dropbox\Research\Mestizo\Code>python doctext.py censo_19940_tab_corta-30.png -out_file out.jpg
我得到以下错误和回溯:
Traceback (most recent call last):
File "C:\ProgramData\Anaconda3\lib\site-packages\PIL\ImagePalette.py", line 99, in getcolor
return self.colors[color]
KeyError: (255, 0, 0)
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "doctext.py", line 96, in <module>
render_doc_text(args.detect_file, args.out_file)
File "doctext.py", line 78, in render_doc_text
draw_boxes(image, bounds, 'red')
File "doctext.py", line 35, in draw_boxes
bound.vertices[3].x, bound.vertices[3].y], None, color)
File "C:\ProgramData\Anaconda3\lib\site-packages\PIL\ImageDraw.py", line 239, in polygon
ink, fill = self._getink(outline, fill)
File "C:\ProgramData\Anaconda3\lib\site-packages\PIL\ImageDraw.py", line 113, in _getink
ink = self.palette.getcolor(ink)
File "C:\ProgramData\Anaconda3\lib\site-packages\PIL\ImagePalette.py", line 109, in getcolor
self.palette[index + 256] = color[1]
IndexError: bytearray index out of range
我已经查看了有关此错误的以前的帖子,但我无法弄清楚这是从哪里来的。
【问题讨论】:
【参考方案1】:问题是我应该使用 jpg 文件时使用的是 png 文件。代码/教程的文档使用 jpg 文件作为输入:
https://cloud.google.com/vision/docs/fulltext-annotations
转换为 jpg 后,代码运行没有问题并产生了预期的输出。
【讨论】:
据我所知,我想补充一点,问题的根本原因是代码需要一个 rgb 文件,而您的 png 文件是 rgba,这导致了错误。 Jpg 文件总是 rgb,而 png 文件可以是 rgb 也可以不是。使用 rgb png 文件也应该可以解决问题。此外,文本注释本身应该适用于所有 jpg/png 文件,只有 PIL 部分受错误影响。 同样的错误,也是由于不是正确的 RGB 格式,在另一个 post 中可以看到,它链接到 this 简洁的解释。以上是关于IndexError:带有 Google Cloud Vision API 的字节数组的主要内容,如果未能解决你的问题,请参考以下文章
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