一、图片变换
0、导入模块
导入相关函数,遇到报错的话,直接pip install 函数名。
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import numpy as np
import argparse
import cv2
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参数初始化
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ap = argparse.ArgumentParser()
ap.add_argument( "-i" , "--image" , required = True ,
help = "Path to the image to be scanned" )
args = vars (ap.parse_args())
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Parameters:
--image images\page.jpg
1、重写resize函数
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def resize(image, width = None , height = None , inter = cv2.INTER_AREA):
dim = None
(h, w) = image.shape[: 2 ]
if width is None and height is None :
return image
if width is None :
r = height / float (h)
dim = ( int (w * r), height)
else :
r = width / float (w)
dim = (width, int (h * r))
resized = cv2.resize(image, dim, interpolation = inter)
return resized
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2、预处理
读取图片后进行重置大小,并计算缩放倍数;进行灰度化、高斯滤波以及Canny轮廓提取
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image = cv2.imread(args[ "image" ])
ratio = image.shape[ 0 ] / 500.0
orig = image.copy()
image = resize(orig, height = 500 )
gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
gray = cv2.GaussianBlur(gray, ( 5 , 5 ), 0 )
edged = cv2.Canny(gray, 75 , 200 )
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3、边缘检测
检测轮廓并排序,遍历轮廓。
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cnts = cv2.findContours(edged.copy(), cv2.RETR_LIST, cv2.CHAIN_APPROX_SIMPLE)[ 0 ] # 轮廓检测
cnts = sorted (cnts, key = cv2.contourArea, reverse = True )[: 5 ] #保留前5个轮廓
# 遍历轮廓
for c in cnts:
# 计算轮廓近似
peri = cv2.arcLength(c, True ) # 计算轮廓长度,C表示输入的点集,True表示轮廓是封闭的
#(C表示输入的点集,epslion判断点到相对应的line segment 的距离的阈值,曲线是否闭合的标志位)
approx = cv2.approxPolyDP(c, 0.02 * peri, True )
# 4个点的时候就拿出来
if len (approx) = = 4 :
screenCnt = approx
break
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4、透视变换
画出近似轮廓,透视变换,二值处理
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cv2.drawContours(image, [screenCnt], - 1 , ( 0 , 255 , 0 ), 2 )
warped = four_point_transform(orig, screenCnt.reshape( 4 , 2 ) * ratio) #透视变换
# 二值处理
warped = cv2.cvtColor(warped, cv2.COLOR_BGR2GRAY)
ref = cv2.threshold(warped, 100 , 255 , cv2.THRESH_BINARY)[ 1 ]
cv2.imwrite( 'scan.jpg' , ref)
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二、OCR识别
0、安装tesseract-ocr
链接: 下载
在环境变量、系统变量的Path里面添加安装路径,例如:E:\Program Files (x86)\Tesseract-OCR
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tesseract - v #打开命令行,进行测试
tesseract XXX.png result #得到结果
pip install pytesseract #安装依赖包
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打开python安装路径里面的python文件,例如C:\ProgramData\Anaconda3\Lib\site-packages\pytesseract\pytesseract.py
将tesseract_cmd 修改为绝对路径即可,例如:tesseract_cmd = ‘C:/Program Files (x86)/Tesseract-OCR/tesseract.exe'
1、导入模块
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from PIL import Image
import pytesseract
import cv2
import os
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2、预处理
读取图片、灰度化、滤波
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image = cv2.imread( 'scan.jpg' )
gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
gray = cv2.medianBlur(gray, 3 )
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3、输出结果
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filename = "{}.png" . format (os.getpid())
cv2.imwrite(filename, gray)
text = pytesseract.image_to_string(Image. open (filename))
print (text)
os.remove(filename)
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原文链接:https://blog.csdn.net/weixin_44942126/article/details/114162934