從圖像中提取文本

Question

我需要從圖像中提取字符，但是由於周圍的光效，圖像變化很大。 因此，我無法修復任何特定的預處理方法。

我的預處理代碼如下所示：

from skimage import io
import cv2
from skimage.filters import threshold_otsu, sobel
from skimage import img_as_ubyte
import numpy as np
import matplotlib.pyplot as plt
from skimage.color import rgb2gray

image = io.imread(imgg)
dim = (700, 100)   #76 pixels
resized_image = cv2.resize(image, dim, interpolation = cv2.INTER_AREA)

image = rgb2gray(resized_image)
threshold = threshold_otsu(image)
bina_image = image < threshold

img = img_as_ubyte(bina_image )
image_copy = img.copy()
kernel = np.ones((3,3), np.uint8)
clahe = cv2.createCLAHE(clipLimit=5.0, tileGridSize=(1,1))
img[:,:,0] = clahe.apply(img[:,:,0])

imghsv = cv2.cvtColor(img, cv2.COLOR_BGR2HSV)
imghsv[:,:,2] = [[max(pixel - 25, 0) if pixel < 190 else min(pixel + 25, 255) for pixel in row] for row in imghsv[:,:,2]]
imghsv[imghsv < 170] = 0
imghsv[imghsv > 170] = 255

我嘗試過 tesseract、EasyOCR 和 KerasOCR 等 ocrs，但沒有一個適用於這種情況。 你能建議我如何從這些圖像中獲取所有字符嗎？

Answer 1

文本二值化代表了在不同光照和噪聲下的復雜任務。 諸如灰度級、亮度和背景的變化等因素使閾值方案復雜化。 如果你有足夠的資源，我推薦你谷歌雲視覺

實現它的代碼很容易理解：

def detect_text_uri(uri):
"""Detects text in the file located in Google Cloud Storage or on the Web.
"""
from google.cloud import vision
client = vision.ImageAnnotatorClient()
image = vision.Image()
image.source.image_uri = uri

response = client.text_detection(image=image)
texts = response.text_annotations
print('Texts:')

for text in texts:
    print('\n"{}"'.format(text.description))

    vertices = (['({},{})'.format(vertex.x, vertex.y)
                for vertex in text.bounding_poly.vertices])

    print('bounds: {}'.format(','.join(vertices)))

if response.error.message:
    raise Exception(
        '{}\nFor more info on error messages, check: '
        'https://cloud.google.com/apis/design/errors'.format(
            response.error.message))